Rising Sap: I Keep Thinking It's Spring

With both the Winter Solstice and recent bout of plummeting temperatures behind us, it feels as if spring is around the corner. I have to keep reminding myself winter has barely begun, rising sap or no rising sap. And it's not even as if things were warm outside, not with temperatures running about 3 deg C.

Encouraged by healthy new fuchsia growth on cuttings taken last October, and - as you shall see shortly - by similar growth in the coffee jar propagator, I could not resist taking some new cuttings, just to see if they will take (yes, I know it's foolish - we usually get a break like this in the winter weather (though usually later, about mid-February)). I had trained myself to resist the said temptation. But this time it somehow feels different. I don't know why. Perhaps it's with being so close to the Solstice.

The lengthening days have not gone unnoticed by the plants (they use phytochrome to detect these, as you will see). If I keep talking like this I'll have sap running in my veins.

Surprise Beneath the Fleece

I don't have to tell you it has been cold. And when I say 'cold', I do mean 'COLD' (us Brits are a bit 'nesh', to say the least - except for our Scottish contingent who can chew nails and spit rust). So I could hardly believe my eyes to find this fuchsia looking up at me the other day. It has been under a double fleece plus three sheets of newspaper for at least two weeks. Incredible. I thought it would have been long gone. However, not only has it survived, it doesn't even appear to want to shut down.

As you can see, there seems to be only the slightest hint of frost damage. Temperatures have not been that low - not with a 60 watt tubular electric heater in the porch - but they have been well below zero on several occasions, otherwise consistently just a couple of degrees above freezing.

But it's not just the temperature: it's the light, or lack of it (because of the newspaper). I thought there would have been signs of chlorosis (yellowing) before now.

PERHAPS THE CLUE IS IN THE FLOWERS
I'm not sure if you can see them, but apart from the healthy green colour, what really struck me were the fresh flower buds. Flowers in December? Amazing. Well, perhaps not:

Flower buds are laid down in the meristems long before there is any hint of their existence. And with temperatures being so low for so long, there has been little development in the growth process. Growth slows down dramatically as temperatures fall. And if I were to say that the cuttings taken in October have taken 8 to 10 weeks to develop roots (versus 10 days in May), it becomes clear that these flowers might have been developing for at least the same amount of time.

Nevertheless, this plant's persistence makes me think there is some sort of 'determined effort' to flower at all costs - to finish the job it has started. I know this is ridiculous. But who knows? Stranger things have happened at sea . . ..

Triphylla Fuchsias Do Not Like Cold

Just a couple of weeks ago, things were looking up for the troubled triphylla fuchsia. It seemed to have recovered and was looking really healthy, though rather uneven. Now things don't look so good.




Although the smaller leaves are not too bad, the larger ones seem to be losing green chlorophyll, giving them a rather insipid appearance. Cold can cause loss of chlorophyll, but they also seem to be dying back. So I'm not sure whether the problem is the cold, or the low day length and light levels (or both). However, it is well known that triphyllas do not like the cold.

Hopefully, things will improve if temperatures and light become more favourable. It will be interesting to follow developments. Funny how a few odd plants seem to suffer all the woes whilst others seem to sail through life. A bit like us, I suppose.

After-Christmas Hyacinths

I don't know about 'After-Christmas', these hyacinths might not even make it by February. So much for letting them grow in their own time to make stronger plants.

Temperatures have been running at little over the growing threshold for the past few weeks (most plants do not grow at temperatures below 6 deg C - this is why you will see your daffodils growing in spurts during the warmer spells of winter). I am surprised. For some unknown reason I had thought this temperature limit might not apply to hyacinths.

Of course, it's always possible they do not like the multi-purpose compost (I did not use bulb fibre, to keep costs down).

Supercooling Helps Plants Resist Frost

When a solution's temperature falls below freezing point without ice crystals forming, it is said to be supercooled. Some plants are able to do this, and so can withstand freezing temperatures (many fish can do this as well). We saw recently how plants can avoid ice damage by removing fluid from the inside to the outside of their cell walls, where it can freeze between the cells without causing damage.

This article not only illustrates supercooling, it also shows how the latent heat of fusion released by this liquid as it turns to ice raises the temperature to the extent of 80 calories per gram of ice formed (This also illustrates the usefulness of spraying crops with water on the evening before a frost).

It also mentions that plants induce this supercooling by producing such compounds as sugars, amino acids and other solutes; also that plants produce antifreeze proteins and other low molecular weight compounds, which 'provide freeze tolerance by inhibiting ice crystal growth and the nucleation of ice crystals' (crystal structures form around a nucleus - usually a solid one such as dust (though obviously not inside a cell)).

Should Geranium Shoot Growth Dictate Pruning?

I hope you can make out the strong new shoots which have grown from the collapsed stems (due to growing too fast) of this geranium. The point here is they have grown in the gap without any encouragement (the stem has not been cut back), almost certainly because the spot has received unrestricted sunlight; nodes further up the stems, which are in the shade because they are behind other stems, have not developed. This looks like phytochrome at work again.

Of course, it could just be coincidence. And, strangely, I have never before noticed such a response. But if new shoots have a preference for non-shade, then it will pay to prune accordingly. In other words, the plant can be pruned into a conical rather than a mushroom shape, thus helping ensure all new buds are free from shade.

Note that when a stem collapses into a horizontal position, the dominant effect of the apical bud is removed and the axillary buds lower down the stem are able to develop (they were previously restricted by auxin produced by the apical bud) into several upwardly-growing new shoots. This effect can often be seen on fallen trees which still have some roots left in tact.

Going Back to Basil. Are Low Energy Lights the Problem?

It's been bothering me all year. I don't like failure, at the best of times. And to fail at the first hurdle . . . Well! But those who have read the early posts know this is just what happened - the very first seeds (basil) failed to germinate, and I wasn't really able to give a satisfactory explanation (I put it down to temperature). Now, after reading something more about the effects of light quality on lettuce seed germination, I have had a re-think. I don't know why I never saw it before. Basil might also need a light stimulus to germinate.

The seeds were placed near a low-energy fluorescent bulb, so were probably low in essential orange-red (660nm) light. This seems especially apt since basil comes from a part of the world where natural light contains much light of this wavelength.
The more I think about this explanation, the more it makes sense. Although the propagator was warmer than the original position, it was also in stronger natural light.

Note that phytochrome stimulation does not need strong light, as does photosynthesis. A low wattage tungsten bulb is effective.

Don't Confuse 'Phytochrome' with 'Photosynthesis'

I realise that all this talk about phyto-this and phyto-that might be more than a little confusing, especially if you have no previous knowledge of biology. I would really like to go through it all and explain it to you (at least as far as I understand it), but it takes up an awful lot of space.

Although this blog is about growing plants successfully, I feel that a deeper knowledge of how plants operate is not just USEFUL but ESSENTIAL in achieving this. Of course, you don't need to absorb every detail, but I think it's good to know where things are coming from. And you can always do some of your own research - there's loads of readable information on the Internet. Even though some of this could present a more accurate picture, by selecting those web pages you can get on with, you can learn more about plants and how they grow. Don't try to take it all in; just have a look; it will all make sense eventually.

By the way, Phytochrome is a blue PIGMENT which the plant uses as a photoreceptor with which it can determine light quality and also probably day length. Photosynthesis, on the other hand, is a PROCESS - one in which a plant uses green chlorophyll to manufacture the sugar glucose.

Not As Much Frost Damage As Expected?

Such a prolonged bout of freezing temperatures so early in the winter is uncharacteristic for the UK; I am sure I'm not the only one caught out. However, at first sight, thank goodness there doesn't seem to be as much damage as expected.

I was really surprised when dahlia tubers close to the surface and pulled up with dead stems were not frozen; they had only had a covering of loose, dead leaves. I find leaving the old vegetation gives much protection to the over-wintering tubers - it's a bit messy, and it also shelters pests, but it is good for both the tubers and the soil (dead leaves gradually break down and help structure; many are even pulled down by earthworms).

However, the winter is still young. As usual, I have probably spoken too soon.

Hydrangea Mops Protect Buds From Frost

I usually leave the foliage on old plants to give some sort of structure to the garden during the bleak winter months. Often these look untidy, but they come into their own when the frost arrives, and can on occasion look quite spectacular. However, there is more to it than this. These frozen hydrangea mops are protecting the buds on the lower parts of the stems from frost. They say this is because cover cuts down heat loss to the atmosphere by radiation, though I find this hard to appreciate fully.

I have found that frost seems to be far more damaging if it is allowed to settle on the plant - even glass gives considerable protection in this regard, though will do little to cut down heat loss through radiation (radiated heat passes straight through it, as it does through a tungsten light bulb).

As far as the hydrangeas are concerned, best not to remove the mops until late spring when the stems can be cut back to strong buds.

Should We Dig in the Dark?

I know the ground is frozen solid, but for those of you with some digging still to do in weedy soil, here's something to consider:

As mentioned elsewhere, many seeds are sensitive to the quality of light for germination; this helps them grow in ideal positions. Some species require an open site; others prefer company. By assessing the quality of light (i.e. its constitution), they are able to determine their position.

How do they do this? They use a pigment called 'phytochrome', which is capable of determining the proportions of red and far-red light available. Leaves filter out red light whilst far-red is filtered much less, hence decreasing the red:far-red ratio. Those seeds requiring an open position germinate when there is a high proportion of red light available, and vice versa.

Many garden weeds germinate following light stimulation, often for just a few seconds. Digging in the dark would deprive exposed red-light-requiring weed seeds of this stimulus and hence hence reduce germination up to four-fold (since they would have the impression that they had landed in shade).

Before you rush for the spade handle and the flashlight, please bear in mind that this is only an idea, not - I think - one to be taken too seriously. . . although I don't know . . .?

Watch Sun on Frozen Evergreens

We have recently seen how plants can survive hard frosts by reducing the water content in their cells. And if things get really bad, the roots can freeze as well. The plants react as they would in drought: they shut down and begin to wilt, as seen here with this frozen fatsia, which has dropped its leaves down by its side awaiting the thaw.

This is a particularly dangerous time for many evergreens, especially young ones with tender tissue and shallow roots. A drying wind could leave them unable to replace any water which might be subsequently lost, thus causing scorching. Strong morning sun is also a problem on such plants as camellias which might have similar difficulties in frosty weather.

Hyacinth Shoots Through

I had almost forgotten about these hyacinths under a bucket in the garage. They are certainly going to have to get a move on if they are to flower for Christmas. No, seriously, there's not much chance of that; they are not developed enough, probably because it has been too cold. Of course, I could always warm them up and force them along. But I don't want to do this; they will turn spindly and thin. Better to wait and let them flower in their own time.

Plants have all sorts of ways to tell what time of year it is and where they are. Hyacinths need to go through a period of several weeks (preferably at least 10) of cool darkness, so they can be fooled into thinking they're underground and it's spring. Many seeds and storage organs need a prolonged period of temperatures around freezing before they will flower, a process called 'vernalisation' (some seeds need cold treatment before they will germinate; a process called 'stratification') . Fortunately, this fact has been accommodated by the retailers who have pre-treated their wares. Special 'Christmas' hyacinths have already been heat (cold) treated, so all we need do is plant them cool and dark till they come through, then place them gradually into a light.

Note that the shoots are just starting developing chlorophyll (the stuff they need for photosynthesis) and turning green in the light. The compost is mouldy and too damp. This could be because I used multi-purpose instead of bulb fibre. I know it's not ideal, but the idea of 'My Broken Garden' is one-size-fits-all, if possible, since this keeps the costs down.

Fuchsias Seem to be Thriving Now

It always seems to happen. I don't know why. But whenever I make a definitive statement, I seem to end up eating the words. It seems plants have personalities like we humans - they will do everything they can to resist being labelled and understood. These thriving fuchsia cuttings are a case in point. They appeared to be on their last legs a couple of weeks ago. Now they look as if they have been given a new lease of life.

I know I should be grateful. I am, really. But I wish I knew what's happened and why. I would like to report that we have now overcome the botrytis and shortening days, but reason says otherwise. Anyway, it's just as well they're surviving - with the sudden unexpected low temperatures, I might have lost quite a few of those in storage.

Dormant Bulb

If you're wondering why I'm showing you a drawing (don't you think my hand's becoming steadier since I gave up the drink?) of an 'onion', can I just say, that's not an appropriate attitude. No. With the hyacinths and daffodils now through, I thought I might point out firstly that a bulb is not a root, it's a modified shoot (I never shall get the hang of this botany thing - just when I thought it was safe . . ..). It has a very short stem and fleshy storage leaves. Also, the roots are called 'adventitious' because they grow from the stem.

The amazing thing about bulbs is that they contain next year's plant in miniature, including the flowers. So if you buy bulbs from the nursery or garden centre and they fail to flower during the season, don't blame yourself, it's not your fault - it was the bulb's (or the nursery's).

Incidentally, if your daffodils have been blanking (growing leaves only, without flowers) recently, they might have become over-crowded. Try lifting them and re-planting - it often does the trick. Add a little bonemeal to the soil first to help them along.

Patchy Triphylla

Due to recent hard frosts, I have brought the triphylla fuchsia indoors (they don't like being too cold). Now that it is growing a little, you can probably see the problem: growth has become patchy, limited mostly to the perimeter of the plant. The withering leaves reported earlier were confined to the centre, and this tendency seems to have been stopped by watering, indicating that the core of the plant was too dry.

TWO BIRDS WITH ONE STONE
The problem has been how to water without bringing on botrytis through the subsequent cold wet conditions. So I have had to keep it dry to fight the botrytis. Growing indoors should 'kill two birds with one stone': It should allow watering, whilst controlling botrytis (due to being warmer). The only problem might be that it goes leggy. I have given it a full sun position to try to avoid this.

Disbudding Cuttings Improves Growth

You will often hear it said that it pays to remove buds from cuttings because they take up energy which could otherwise be used for growth. Whilst this is undoubtedly true, it is not my main reason for dis-budding.

Once a cutting starts to form flowers (and most of them do, surprisingly early) it stops producing new stem and leaves. This is a problem for me, since the growing season is already too short (apart from insurance, this is why I take cuttings for next year's plants - to give them a longer season). I like the plants to get some growth over the winter months, albeit apparently somewhat stunted; this will give them a really good start next season.

Take care when removing the buds, not to disturb any delicate new roots which might have formed.

Should We Keep Pots Wet or Dry in Winter?

This is the $64k question. It's a situation where growing suddenly becomes an art: where something which sounds easy to work out on paper suddenly becomes incredibly complex.

Just in case you don't want to follow the story (and who can blame you?), here's my advice: KEEP THEM AS DRY AS YOU CAN (i.e. don't water them unless you really have to). If you are unsure, stick in a thermometer and check things out.

CONDUCTION, CONVECTION AND RADIATION
We are back to conduction, convection and radiation again - with something called HEAT CAPACITY thrown in for good measure.

Heat Capacity
This is the amount of heat required to raise the temperature of an object by a given amount. Both water and bricks have high heat capacities. This means they are slow to warm up (think of coming home to find the heating has been off for a few days and how much heat it takes to get back to normal). Whilst this isn't good when planting in spring, it is fantastic in winter, since it means pots of wet soil/compost kept close to the house are much slower to freeze than they would otherwise be (think of standing next to a storage heater). So we just water pots and keep them close to the house? If only it were that simple.

WET COMPOST PRODUCES TURGID CELLS
Much depends upon whether the frost is severe enough - either through a large drop in temperature, or through the length of exposure during a prolonged cold spell - to cause the compost to freeze solid. Should this be the case, we can be in trouble. We saw recently that plant cells are damaged by the formation of ice crystals within turgid (full of fluid) cells, since the sudden expansion can rupture the cell walls. This is the problem with watering the compost; there is no way to prevent this water entering the plant and producing these turgid cells.

DRY COMPOST PRODUCES FLACCID CELLS
However, the flaccid cells produced in drier compost not only have more concentrated sap (which freezes at a lower temperature), but can also accommodate any ice crystals which do manage to form. This seems like a better situation. But things are complicated by the fact that plants, even in damp compost, can produce this situation by hardening themselves, as we saw elsewhere.

CONDUCTION AND CONVECTION
Sandy soils can be a problem for two reasons:
They are good heat conductors, so easily bring heat to the surface from down below.
They have large pores through which air currents can easily pass and remove heat by convection.

These soils tend to be too hot in summer and too cold in winter. The problem is made worse by the fact they cannot hold much water.

RADIATION
Lighter soils tend to be cooler, since they reflect the sun's heat back in summer and are reluctant to reflect valuable soil heat in winter. These effects are lessened if the soil is wetted, since it inevitably becomes darker and therefore a better radiator.

EFFECT OF MULCHING
Mulching can provide a solution. I like to apply dry peat or potting compost to pots and delicate plants just before a severe frost. This provides an insulating layer and helps considerably. Garden compost has a similar effect. If applied at this time, the lighter frosts will have had a chance to kill off some of the pests which might be in the surface layers. If using potting compost, take care not to use it around lime-hating plants (calcifuges).

How Plants Lose Heat

The best way to protect plants against frost is to understand how they can lose heat (note that they lose heat, not gain cold), then take appropriate action. There are three main ways:

Convection
Conduction
Radiation
Evaporation


CONVECTION
Associated with air currents moving around the plant and soil (think of putting on a jacket to keep out the wind). Most plants (and objects) have a layer of still air close to their surface, which acts as insulation. Air currents remove this. Some plants have leaf hairs, which help matters since they help trap this layer of air. Although the main function of this is to cut down water loss, it also helps insulate the plant. (and if the hairs are light in colour, they also aid cooling by reflecting back the sun's rays).

CONDUCTION
Associated with heat loss through making contact with a surface with a different temperature (think of touching cold metal with a warm hand). Since the ground is invariably warmer than the air on a frosty night, this usually warms the plant.

RADIATION
Even bodies in a vacuum can gain and lose heat by radiation, provided the sides of the vessel are clear; no air or contact is necessary. Dark objects are the best (or worst) radiators; light ones vice verse. As recently mentioned, fleece (because it is white) cuts down radiant heat loss (by reflecting back any heat trying to escape this way). We also saw in the summer that black pots could cause compost temperature to rise so much that roots could literally boil. Covering the pot with shiny aluminium foil helped prevent this and reduced temperatures considerably in the tomato pots. Foil will work the other way in winter.

EVAPORATION
Plants cool themselves in summer by 'perspiring' water through the pores (stomata) in their leaves. The act of turning water at 100 deg C to vapour at 100 deg C uses up much energy and takes this as heat from the plant, thus cooling it. The heat needed to do this is called 'latent heat of vaporisation'. The process of plant water loss is called 'transpiration'.

Water acts in the opposite way at freezing point, when it turns from liquid to ice - it GIVES UP HEAT to the plant surface and thus lowers the freezing point slightly, often just enough to prevent damage. Market gardeners spray their crops before nightfall when spring frosts are forecast.

The Worst of All Frosts

In the UK, a bitter east wind (forecast for later in the week) provides the worst of all frosts - a penetrating one. It might take more than horticultural fleece to protect sensitive plants.

Fleece insulates plants by preventing radiant heat loss and to some extent restricting air movement around them. But I don't think it will be strong enough to protect against strong air movements; these will brush aside the still air (because it's porous) and allow freezing temperatures to reach the plant surface.

Much protection can therefore be obtained by blocking up cracks in doors and windows through which this wind can pass. I am also going to cover plants with newspaper overnight to help reduce air movement around them. Fortunately, daytime temperatures should remain above freezing.

Don't Paint It Green

If you're thinking of giving your growing area a bit of a face lift some time soon, can I give you some advice: Don't paint it green. As you can see from this approximation of the absorption spectrum of chlorophyll 'a' (it shows how much of each colour the plant can use), plants use hardly any green light, tending to use light from the blue and red ends of the spectrum for photosynthesis.

I remember thinking it such a good idea to paint my rear porch green, only to discover much later this was why the plants weren't prospering - not the poor season which subsequently followed. It never occurred to me that plants are not really green: they only appear green because the chlorophyll (and other pigments) has absorbed all the other colours from the visible spectrum, leaving just the green light (or whatever an object appears to be) to be reflected to our eyes.

I find white the best colour for a growing room, especially this time of year when plants benefit from as much reflected light as possible. You can even use tin foil in the winter, though it tends to be too much when the sun gets stronger. Like we humans, plants can also suffer sunburn.

Coming or Going? Short of Phytoalexins?

With the shortening days and weakening light of late autumn, plants want to shut shut down and have a good long sleep till spring. Then they can awake refreshed about early February when things are picking up. Just like us, as tiredness sets in and they become weaker they are extremely susceptible to disease, since they have no vigour with which to resist it. Resist it? How do they do that?

Whereas humans produce antibodies with which to attack disease, plants have other methods:

• Firstly, they can restrict entry by quickly forming calluses (the plants' equivalent of scabs) over wounds.
• Secondly, they can produce toxins; woody plants, for example, often produce resins, which act as poisons. However, they can also react more actively.
  

ACTIVE DEFENCE
In the 1940s, scientists discovered that infected plants could react actively in response to fungal attack by producing substances which they called 'Phytoalexins'. Since that time about twenty phytoalexins have been discovered, of which each plant species uses one or two. Unlike antibodies, they are not species specific, so just like a contact fungicide they can be used against a wide range of fungal infections.

Now back to the fuchsias. It is hard to know whether the suddenly-yellowing leaves are caused by the plants trying to shut down, or whether it is our old friend botrytis gaining the upper hand as the plants lose vigour. Just a couple of weeks ago I noted how the healthy fuchsias grown in soil outside had resisted this disease. Could this be evidence of phytoalexin use by fuchsias?

Checking the Drainage

As you know, I have now lifted and stored some of the dahlias. But I usually leave some in the ground all winter. They seem to survive very well like this, especially if planted deep (at least 10 cm) and get some sun during the day. The sun thaws out any frost and prevents it penetrating deep into the soil during any weeks of continuous 24 hour bouts of freezing temperatures, usually in late December-early February when days are shortest. If storage is a problem, you can do this as well, with one proviso: the soil must not become water-logged.

What causes water logging? - Poor drainage.

How do you know if you have it? Dig a narrow hole about a spade deep and watch it. If it doesn't drain within about 8 to 10 hours after a bout of heavy rain, then drainage is a problem. If it doesn't rain, tip in a bucket of water. (Incidentally, if it drains too quickly, this indicates another problem - too-light soil (remedy by adding clay or compost)).

FACTORS CAUSING POOR DRAINAGE

High Water Table
As winter approaches, the water table gradually rises and can even reach the surface causing bogginess, even permanent puddles of wataer. This problem usually occurs with low-lying land; it does not affect most gardens since it is low enough beneath the surface. However, if you have this problem, you should think about a drainage system. Unless you do this, your plants will never do well (unless, of course, they are bog plants).

Heavy Soil
Heavy soils, such as clay, do not drain fast enough in times of continual rain. Dahlia roots (and also those of many other plants, especially bulbs and corms) do not like this and will quickly rot. Planting in sand will help to keep the cold wet earth away; it will also improve drainage by keeping the soil open. Adding compost, sand, or horticultural grit will help to improve the drainage.

Hard-Pan
If you live in a new property (or an older one), the garden might have been created by dumping topsoil onto what was effectively a building site compacted by heavy traffic. As the surface water seeps down, it is prevented from getting away by this layer and thus creates a false water table.

Hard-Pan can be cured by penetrating the pan, the more places the better. Although double-digging is best, just loosening the soil in spots close to each other will have a large effect. If you do double-dig, try to avoid mixing the subsoil (usually the lighter soil) with the topsoil (the darker soil), since it is invariably infertile. After removing the first spadeful, try to loosen the lower layer without lifting it out; this will allow the water to get through.

Patience Produces Short-Jointed Geraniums

Look how much shorter-jointed (shorter internodes) the geranium on the left is, compared to its partner: the larger cutting (which received normal feeding) we took in late summer. Furthermore, look how many axillary buds are developing into new shoots.

What's that: 'So what, you're not impressed'?

Well, think of it this way: Each new shoot will bear a flower. So the more shoots we have . . ..

Of course, this does't happen overnight; it takes time - too much time for most growers. But you might remember me telling you earlier that patience is a virtue when growing plants. Growing this plant slowly in almost dry soil (you can use compost - preferably seed and cutting compost, since it contains less food) with little or no feed is the proof of the pudding.

It's that hard growing again. And in my experience, this will reward you time and time again. Both plants are good cuttings. They will both make good plants. But I fancy the hard-grown one. Let's wait and see . . ..

I Should Have Node

This winter twig should demonstrate what is meant by nodes and internodes, at least as far as plants are concerned.

Axillary buds (those between the stem and leaf base) become dormant after leaf fall (as demonstrated here). So technically I should have labelled it 'dormant bud'. These are the buds we cut back to when pruning, the problem in older wood being they can be almost impossible to detect. Many's the time I have cut back an old woody stem only to discover buds developing in the most unexpected places.

As far as we growers are concerned, the internodes are important, since long ones develop into straggly plants. Light and temperature are key factors in this.

Dahlia Tubers Ready for Storing

The soil on the inverted dahlia tubers in the garage has now dried sufficiently to turn them right-way-up. The tubers are not soft but are not nearly as brittle and delicate as they were - drying has made them leathery, ideal for resisting light frosts. I will not cover them until harsh frosts are forecast. This will help keep the necks (the part where the stem meets the tuber) dry and rot-free.

TUBERS ARE NOW DORMANT
This is the only washed tuber on its way to the fridge (it hasn't got there yet). It's not my day for photographs, but the small reddish dots on the neck (roughly in the centre of picture) are the dormant axillary buds from which next year's new growth will emerge. The fact they are not developing shows that the tuber is dormant, probably because of low temperatures and loss of foliage.

Crocus Bargains

These crocus corms seemed a real bargain: the store was clearing out old stock. You need to be careful about buying old bulbs and corms, but although these corms are growing, they are still quite firm and have no roots showing. This would indicate they are free from disease and simply aching to get growing properly.

I added them to the autumn arrangement; it's looking a bit sparse, since I didn't have any spare corms when I made it up. I just stuck my finger in the compost to make a hole then carefully pushed them in. They might be a little later flowering, but it is surprising how things in nature have a way of catching up - re this year's nearly normal summer after the harsh winter and cold spring.

Cutting Back Geranium Stems

When geraniums get too straggly, their stems can be cut back to strong-growing side-shoots. You don't have to do this; you can cut to an axillary bud (bud in the axil where the leaf meets the stem). But I find this is not so reliable and can lead to loss of the bud. Be careful not to cut too close to the new shoot (leave at least 5 mm of stem).

I usually cut back one or two long stems per plant at one time (you can cut them all back if you don't mind the complete loss of flowers for a few weeks), choosing shoots which will help shape the plant appropriately. The idea is to get as many new shoots growing from as close to the base as possible, helping to keep the plant compact.

Don't forget to make new plants from the cutting material. If you don't want to pot them up, just stick them in the compost around the plant. They will probably grow into new stems and should soon blend and appear to be part of the main plant. This principle is called 'multi-planting' and is something we shall be dealing with very soon.

Roses Cut Back

I finally cut back the roses this week, leaving about 15 cms (6 inches) of stem. Not so much as last year (down to 5 cms); but afraid of another hard winter.

They have flowered very well this year, but seem to have given a very heavy first flush and no second; then a third, and were just budding up for a fourth. This is probably because I have given more feed than normal at the start of the season.

Blackspot does not seem to have been much of a problem this year, probably because they were cut back so much. Cleared away all old rose leaves. Will probably spray the stumps (blackspot over-winters on the stems) and soil surface (it over-winters here as well) in mid-winter to kill any over-wintering spores.

Geraniums Seem to Thrive on a Hard Time

This straggly geranium has certainly had a hard time, of late. After recent over-watering, it is now recovering. And the loss of the older leaves has not stopped it flowering. In fact, it's flowering better now than it has done all summer, despite the over-watering, despite becoming pot-bound, and despite not having been fed for over two months (it was fed every third watering in the summer).

It seems geraniums (pelargoniums) thrive on a hard time. Provided they are not kept too wet for too long, they will do everything they can to prosper. If ever there was an ambassador for 'hard growing', this plant is it. Careful pruning and watering should now help it build into an attractive plant.

Triphylla Fuchsia Surviving Botrytis

After treating with sulphur powder (I got a bit carried away), it is hard to tell whether the triphylla fuchsia is surviving the new botrytis attack, or not (the photo doesn't help much, either, sorry). But things appear to be more postitive: There seems to have been some growth around the edges.

I don't know if you can see, but the leaves have looked strange since applying the 'Systhane'. However, the new shoots look quite strong. So might get some new cuttings yet.

Taking Geranium Cuttings

I thought I had published this article in July. Sorry. I've amended it slightly.

Pot geraniums (pelargoniums) are one of the easiest of all plants to propagate from shoot tip cuttings. There is still time to do this if you have a spot which gets some sun. Don't use rooting powder or any form of propagator - Just cut off about 7.5 mm (3 inches) of stem (flowering or non-flowering), carefully tear away the lower leaves and leaf bracts, then push them into slightly moist soil or compost. To avoid disease, use the compost as it comes straight from the bag (add some perlite or sand if you wish); do not add water.

Removing any developing flower buds will speed growth, since more food will be available for structural development. Keep them in good light.

GETTING THEM TO BRANCH BENEATH THE SURFACE
If you take care not to damage the axillary buds when removing lower leaves and leaf bracts, they can develop into new shoots and push up through the compost as if by magic. This has the effect of keeping the initial branching as low as possible, hence producing a bushier and more attractive plant.

You can then induce further branching by pinching out the shoot tips after every 2 or 3 nodes (places where leaves join stem).

Give the as little water as possible (water from below when necessary, never from above) over winter to avoid disease.

ROOTING IN PERLITE AND WATER
Geraniums will also root very well in perlite and in water. See 'Rooting Geraniums in Perlite and Water'.

See also 'A Cut Below Average' . Click 'Geranium' category to see all geranium posts.

Vine Weevil Damage on Pansies in Containers

Vine weevils love to over-winter plants in containers, especially if they have some nice fresh pansy leaves (and later, roots) to feed on. The semi-circular chunks missing from the edges of the leaves reveal their presence. However, they do not usually chew holes in the centre of the leaves.

A dose of 'Provado Vine Weevil Killer' (9g/litre thiacloprid, mixed at 30mls per litre of water) will protect containers until spring.

Vine weevils (especially the grubs, which chew through the roots) are also a problem for primroses, often used in winter containers as a source of bright colours. 'Provado' protects these as well.

Is Systhane (Myclobutanil) Effective Against Botrytis in Fuchsias?

Watering with 'Systhane' at normal strength does not seem to have worked on the triphylla fuchsia I treated last week.

The botrytis seems to be reviving in the freshly-dampened compost. It also seems to have survived on other cuttings of fuchsias, as well; the fungus has been restricted but not apparently killed. I don't know if a stronger dose would do the trick.

TIME OF APPLICATION MIGHT BE CRITICAL
Synthetic fungicides are usually curative in action (and can also be preventative, as well, if applied before infection), so they should work on the mature fungal body (mycelium) and not just the spores. They attack the fungus metabolism at a particular - and usually very specific - stage.

So application at the right stage is essential. (Myclobutanil, the active ingredient of 'Systhane', works by inhibiting the biosynthesis of sterols (enzymes used by fungus) in fungal membranes). Nevertheless, I would expect sterol inhibiting to be effective at any stage. However, to be fair, there was never any claim that 'Systhane' is effective against this disease. But here's something strange:

These young fuchsia cuttings are completely free from botrytis, yet they are sealed in a cool (10 - 12 deg C) damp propagator (inverted 200 gram Coffee Jar), and have been for two weeks. Surely these are ideal conditions for botrytis? Why aren't they infected? I don't know. But I'll wager it has something to do with first spraying the cuttings and compost with 'Systhane'.

MORE PROBLEMS
And there's another problem: The damage to these leaves (these are the cuttings you saw last week) has only occurred since I used 'Systhane'. Yet the cuttings in the propagator have not been damaged. Why is this?

Of course, it could be that the damage is not caused by 'Systhane'. However, I think it more likely that damage only occurs when the treated leaves are allowed to dry.

DO NOT USE 'SYSTHANE' ON YOUNG FUCHSIAS
The instructions on the bottle did advise against using 'Systhane' on young fuchsias. So no point complaining too much.

Grey Mould (Botrytis) on Broken Begonia Stem

Botrytis now becoming a real problem: witness this mouldy begonia stem. Like the fuchsia earlier, it's been feeding on sugar in sap oozed from wound. Seems to have already entered stem, probably through vascular system, and has begun to break down the plant tissue, causing rot.

What's worrying about all this? Begonia is still growing. Not yet in storage. But has somewhat reduced vigour from earlier in season, making it easier for the fungus to attack (healthy active plants can fight back against diseases).

CURRENT TREATMENT

• Cut off infected stem at least an inch into clean growth.
• Blotted wound dry with clean kitchen towel.
  
• Sprayed wound with 'Systhane Fungus Fighter'.
  
• Sprayed botrytis spores on old stem with 'Systhane', as well.
  

Perhaps yellow sulphur powder might have been more appropriate, since it would keep the wound dry and is effective against most types of fungi. But 'Systhane' (myclobutanil) is systemic and has a chance of entering the stem (sulphur powder is a contact fungicide) to kill any fungus which might have got in there.

FUTURE TREATMENTS

• Shall have to start dusting all fresh wounds with sulphur powder.
  
• Good idea to spray botrytis with liquid fungicide before handling, to prevent spores being shaken into atmosphere. This would both kill them and prevent dispersal (because they will be wet).
  
• Need to be more vigilant and examine plants every week. All dead plant material should be removed immediately.

LEAVE LONGER STEMS, IF NECESSARY
After removing foliage, leaving a piece of dusted stem about 10 to 15 cm (4 to 6 inches) attached to tuber is a good idea when storing - allows room for fungus attack to be cut away, if necessary. The stems fall off later, once tubers have prepared themselves. They can then be removed.

Outside Fuchsias Doing Fine - No Botrytis

This young fuchsia, taken from a cutting in early summer, has never looked better, despite being potted in garden soil and despite the frost and torrential rains. I have only recently put it beneath the hedge to give it a bit of shelter. Even though there are dead leaves on the soil surface, there is no sign of any disease whatsoever.

It obviously requires more than merely cold wet conditions to induce botrytis. Still and humid air seem the key factors..

It is recommended to keep windows wide open to keep air moving. Starting to feel colder already.

Botrytis Rampant on Fuchsia Cuttings

It's never been a problem before. Now, suddenly, botrytis (at least, I'm pretty sure this is what it is) is really getting going, as seen from this pot of fuchsia cuttings. Cool still air; damp compost - it seems to love these. And I'm sure I doused these cuttings with 'Systhane' not too long ago. It's starting to resemble something from a science-fiction movie.

And the cure is almost as bad. After dusting with yellow sulphur powder, things don't look much better. But it did seem to work with the triphylla fuchsia in August.

Apart from sulphur dust on leaves blocking out the light (which is already in short supply), it is at least dry and does not wet the compost (unlike a liquid fungicide such as 'Systhane'. Just hope it does the trick.

FUNGICIDES WEAR OFF
Fungicides designed to become ineffective after a short time; might be the problem. (It could have been the problem with the Tomato Blight earlier, when 'Dithane' seemed to have become ineffective after 3 weeks).

Strip Geraniums Almost Bare

Shortly after bringing the troubled geranium indoors, it became obvious that, even after spraying with fungicide, the leaves did not look healthy. So, because new leaves and buds were developing, I stripped plant almost bare of leaves and flowers, and re-treated with fungicide and insecticide ('Provado': thiacloprid, a systemic). Should really have done this earlier, but afraid of creating too much stress. Shall re-treat with fungicide ('Systhane') in a couple of weeks.

LAYERS OF QUARANTINE
I ought to have made it clear I do not recommend bringing plants from the garden indoors, at least not without placing them in quarantine for a few days (preferably weeks) first. And I ought to have told you I have areas in my house kept for these purposes so I can strictly observe plants for a while.

If you remember, we took cuttings in August. These were for indoors. They're not only cleaner (because they have come from new growth), they don't need as much room either.

In a few weeks, we can take the shoot tips off this plant for cuttings. Removal of the apical (terminal) buds will encourage plant to branch, ready for next year. This way we 'kill two birds with one stone'. That's the theory, anyhow.

Moss in Lawn

Spotted a strand of moss in the lawn two days ago, so treated whole lawn immediately with 20% ferrous sulphate at 1 ounce per gallon of water per 10 square yards (35grams per 5 litres per 8.5(approx) square metres) . First moss this autumn. Moss usually establishing strongly in mid August and, if left untreated, would be rampant by this time.

I feel liming (reduction of acidity) has improved things. Very tempting to give more lime to see if moss removed entirely. But because of disease risk, best take it gradually by adding no more than 35 grams per square metre (1 oz limestone per square yard) at one time.

As you can see, the damage is not too bad. Can tolerate this over winter. Because grass not cut short, it tends to hide any black stuff (dead moss). I haven't cut it since before it was aerated. As stated elsewhere, 'sulphate of iron' is ferrous sulphate (19%). Application by watering-can at the above rate should do the job.

Definitely worth looking very carefully for any signs of moss (there was so little in mine, I could hardly find the spot after leaving and returning) and killing it before it gets established and reproducing. This treatment should hold it at bay for a month or two. Should be well ahead by spring. Unless . . ..

Troubleshooting Shrivelled Fuchsia Leaves

These shrivelled and spotted fuchsia leaves (centre and bottom centre) have appeared over the past week on the tryphilla fuchsia which earlier survived botrytis.

Apart from the spotting (which usually indicates disease), shrivelled leaves are usually a sign of water shortage, either:

• because the compost is dry or frozen
• because the roots cannot take up water due to damage:

• pests (usually vine weevils) have chewed them (aphids and eelworms also cause problems on other plants)
• they have frozen (or are just too cold)
• soil conditions (such as waterlogging, acidity, nutrient concentration, or toxic chemicals)

My first thought was dry compost, since the plant has not been watered since it was re-potted.

Yes, the pot didn't feel light enough to be completely dry, And I could see healthy roots through the bottom. But I thought it might have had something to do with the drastic treatment the roots had earlier received (excess trimming). And of course, there was also the kitchen bleach given to kill the botrytis.

Failing all this, it could be vine weevils (a major problem with fuchsias kept outside). Although, before repotting, the compost had been treated with thiacloprid ('Provado Vine Weevil Killer') a long-lasting (about 2 months) systemic insecticide.

But it is the dark leaf spot I don't like. This looks like a fungus disease.

Normally there would be no problem - just water and give more 'Provado', in case there are vine weevils, then treat with a fungicide if the plant doesn't recover (water-stressed plants usually recover within 12 hours).

But there is a problem - the botrytis -this thrives in wet compost. So if water is added alone, it will encourage the disease.

So I watered with 'Systhane' (myclobutanil). This should should allow the compost to be wetted whilst preventing new botrytis attack. Things need watching closely.

How Frost Damages Plant Cells

An interesting report from the Food and Agriculture Organization of the United Nations states that it is the formation of ice within a plant which causes frost damage, not the sudden change in temperature. A turgid (full to capacity) cell's liquid contents expand as they freeze and can rupture the cell wall. This damage within individual cells is called 'intracellular'. It often occurs when temperatures drop below freezing point very quickly.

If temperatures fall more slowly, the liquid in the cell has more time to be forced outside through the cell wall. If it freezes here, the damage is called 'extracellular'. It has the effect of forcing the plant cells apart and dehydrating the cells.

DROP IN TEMPERATURE IMPORTANT, NOT LENGTH OF FREEZE
Within a reasonable amount of time (less than 24 hours), it is not so much the time endured at freezing temperatures which affects the degree of damage, but the amount of the drop - the lowest temperatures causing the most damage.

DROUGHT-RESISTANCE IMPORTANT
If ice forms outside the cell (extracellular), even though the cell wall remains undamaged the plant can be slowly killed. This is because the saturation vapour pressure is lower over ice than over liquid water, causing water to move out of the cell towards the ice, and thus death by dehydration.

FROST HARDENING
However, if exposed gradually, plants can harden themselves against frost damage in the following ways:

• removal of water from cell contents, making them more concentrated. This has two effects:
• it lowers the freezing point, and acts as a kind of antifreeze
• it makes the cell flaccid, thus pulling the contents away from the wall and thus making room for frost expansion (see diagram)

• decreasing ice-nucleation active (INA) bacteria concentrations during cold periods, thus allowing super-cooling to occur (cooling of contents below freezing point without the formation of ice crystals)

This hardening occurs naturally as a season become progressively colder. However, a warm spell can cause a reversal to occur much quicker than the hardening, especially if growth is resumed.

Fuchsias Short of Light

These etiolated (stretched) fuchsia cuttings are short of light for the temperatures at which they have been grown. This often happens at this time of year as light intensity falls quicker than temperatures.

The solution is to either move to a lighter place, or lower the temperature (this might have already happened as the autumn has progressed).

Etiolation is a common problem with window sills. And, unfortunately, it is not usually possible to remedy. Should this be the case, I would recommend leaving things for now, then cutting back the leggy growth in February when the light will be stronger.

Typical Plant Cell's Structure and Functions

A typical plant or animal cell is comprised of a filling of cytoplasm containing various organelles, including a nucleus, all enclosed in a plasma membrane. Both plant and animal cells are very similar, except plant cells have a cellulose cell wall around the plasma membrane, plastids (e.g. chloroplasts) and a conspicuous vacuole.

Each organelle has its own special function. Do not burden yourself with these at this stage. This is 'purely for the record':

Cell Wall

The primary cell wall consists mostly of layers of cellulose microfibrils, surrounding the plasma membrane. As the cell develops, further layers of microfibrils are laid down in different directions.

Cellulose has a tensile strength (ability to resist extension) approaching that of steel (cotton consists mostly of cellulose). So once turgid (filled with liquid), the cell is well-supported. The microfibrils are given further strength and support by running through and linking with a matrix of hemicelluloses and pectins.

Further strengthening is achieved by laying down the woody compound lignin.

Between the cells is an adhesive layer of the sticky gel-like magnesium and calcium salts (pectates) of pectins; it is called the middle lamella and holds neighbouring cells together.

Plasma Membrane

This is rather like a balloon which surrounds the cell contents. However, it can selectively allow certain materials into and out of the cell. Some materials are always allowed through; others regulated; others rejected. Thus the cell can, against the laws of diffusion, if necessary maintain a constitution different from its surroundings.

Nucleus

This is the control centre of the cell activity, especially the regulation of genetic material DNA. DNA is contained on the chromosomes and is replicated (according to information encoded in the genes) along with the chromosomes, during normal cell division (mitosis), so that each new cell is identical to its sibling; it is also replicated at gamete formation in sexual reproduction (meiosis). The nucleus is surrounded by a double membrane called the nuclear envelope.

Nucleolus

This is a darkened area within the nucleus and is the site of ribosome production.

Chloroplasts

These contain the enzymes necessary for photosynthesis, plus the green pigment chlorophyll which has the function of absorbing light energy, and gives plants their typical green colour.

Ribosomes

The site of protein synthesis, according to instructions given to RNA from DNA in the nucleus. RNA carries these instructions out of the nucleus and into the ribosomes.

Mitochondria

The site of energy production, the powerhouse of the cell, through a process called 'respiration'. Respiration is the reverse of photosynthesis and releases energy from the carbohydrate glucose.

Endoplasmic Reticulum

A network of parallel membranes which extends throughout the cell. If associated with ribosomes (rough endoplasmic reticulum), its function is to manufacture proteins; if not (smooth endoplasmic reticulum), it is associated with lipid (fat) synthesis.

Golgi Apparatus

This collects, processes and distributes materials to be used inside and outside the cell, e.g. enzymes, and cellulose for cell walls.

Vacuole

A major function of this organ is cell 'skeletal' support. As it takes in water, it extends and makes the cell 'turgid' by forcing the contents against the wall. It also acts as temporary storage for various materials.

Microtubules

A support cell, forming the 'cytoskeleton'. It forms the spindle, a structure used in cell division.

Microfilaments

Also part of the 'cytoskeleton'. They control 'cytoplasmic streaming', the movement of cytoplasm within the cell, allowing the movement of chloroplasts to take advantage of changing light directions during the day.

Plasmodesmata

Pores through which plasma membranes of adjacent cells can connect through tubes (desmotubules) of endoplasmic reticulum. Allows regulated transport between cells.

Winter Geraniums Don't Like Dampness

The fungus mould (probably botrytis) developing on these geranium (pelargonium) leaves is caused by keeping them in too-damp conditions.

After lifting them from the garden and potting them in sterilized soil, I left them in a cold porch at the back of the house, adjoining the kitchen. Of course, every time I have opened the kitchen door, warm damp air has condensed on the cold plants (they don't have to be COLD, just COOLER), leaving a film of water on the surface, ideal for fungus.

After removing the infected leaves, I have now brought them inside the house. Hopefully they will recover when they dry, and we can take some cuttings.

I know I keep repeating it, but you do need to be very careful about damp geraniums over the winter months. This sort of thing happens in garages, as well, when warm wet air from the car settles onto cooler surroundings.

see also Strip Geraniums Almost Bare

Time to Reflect

As the seasons change, new challenges emerge. This season is no different, as demonstrated by the recent unexpected hardish frost. Yet, strangely enough, I find the winter to be one of the most interesting (and certainly most challenging) of times.

Because most plants close down at this time, I suppose it sort of focuses the mind on the growth process of the odd few plants which are still active. Things are moving much more slowly - only ticking over - so there is time to observe (be warned: it's a bit like watching paint dry) and to reflect. And because resources (such as light and temperature) are limited, we are challenged to dig down deeper for creative solutions.

I think it true to say that I have learned more about growing, during the winter months than at any other time of year; and this despite my activities being more or less reduced to window ledges. Strange.

As far as this blog is concerned, I should now have time to discuss and explain all those things I didn't have time for during the season. And in addition, I have some interesting (at least I hope they will be interesting) projects in mind. The only problem is that I am very much in the dark as to whether they will work or not. I hope you don't mind that. But it is how I like to be: trying new ideas and techniques. Of course, needless to say, they usually do not work as intended.

Fuchsias Caught by Frost?

Sunday night's frost was hard for October - looks as if I might have been caught out with the outdoor fuchsias.

I had been awaiting a slight frost to kill the foliage, along with any insect pests living on them, before storing. Too much frost can kill the stems, as well. Still, 'no use crying . . .', so to speak. 'What's done is done', and all that. I put them into the garage before it started raining.

Once the dead leaves have decided to drop, I will completely remove them all, spray the plants with a pesticide, then the plants and compost surface with a fungicide, and await the worst. It should be obvious by mid February whether they have survived or not.

At least the compost is not too wet. Even so, I shall have to watch out for signs of botrytis appearing on any dead material lying on the compost.

NO LIGHT NEEDED IN STORAGE
Fuchsias can be stored in any frost-free place such as a garage or attic. They can even be buried in the ground. Light is not necessary until new growth commences.