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.