Learning how to water plants to increase growth in pots, container or garden - especially how to water roots and tubers. Specialities: root growth or tuber growth of lawns, fuchsias, geraniums, dahlias and begonias.

29 July 2010

Geranium Blotch

sunburn scorch on geranium leafIncessant wet weather is a real problem for containers. Most geraniums (pelargoniums) showing signs of leaf blotches on several leaves.

Although not absolutely certain (see update), don't think this is disease. Concentric scorch marks indicate sun scorch caused by hot sunshine shining though rain drops (which act as a lens).

Never seen them so large before, so not ruling out disease. But normal leaf blotch does not have the scorch rings. Shall have to wait and see.

dithane fungicideSprayed with 'Dithane' just in case. Might help. Hope it clears up soon (the weather, I mean).

Caterpillar Alert

Butterflies look very attractive as they flutter from plant to plant in a garden. Watching them on a summer's day completely belies the fact they are high up on the gardener's list of arch enemies.

Eggs laid in rows on the underside of the leaves of many flowering plants soon hatch into little monsters capable of devouring these leaves seemingly within hours (. . . well. . . days).

Dahlias are particularly susceptible. Beware.

provado sprayThe new 'Provado' spray in the yellow bottle (active ingredient 'Thiacloprid') seems to work well against them.

Basil Update

mature basil plantAlthough basil has been growing steadily all season, it's now time to harvest the crop. Project not really been successful, despite final size of plant.

Extremely slow growth combined with the susceptibility to pests (now having trouble with caterpillars), make it unviable as a commercial proposition - far cheaper and easier to purchase from a supermarket; this variety, 'Sweet Genovese' is the same one they sell.

If you have followed the story, you will know that I selected basil as an easy plant for a beginner to grow. Nothing could be further from the truth. I would definitely not recommend basil cultivation to new growers (nor old ones either, for that matter).

Keeping Them Blooming

Removing fading roses before they start setting seed will help keep them blooming (you should do this for most plants).

If you have several roses clustered on each stem (I do mean stem, not plant), cut off each rose as it fades. Once each cluster has finished flowering, remove its remaining branches by cutting below a good leaf bud lower down on the main stem. This will give stronger growth to the next flush. I know you really need a photo of flowers, not buds, but unfortunately I cut all my roses off before I thought about telling you this. Hope your imagination is better than mine.

22 July 2010

Fuchsias Survive Downpours

fuchsia flowerCovering the fuchsia pots, at least for some of the time, has allowed them to survive about 75 mm (3 inches) of rain within 24 hours (plus much more (we've had about 200 mm (8 inches) since the weather broke)).

It is surprising just how much water flowering plants can tolerate, especially as the leaf canopy thickens. Some leaves are arranged like tiles on a roof and turn almost all rainwater. You need to be aware of this when watering. You might find that certain pots are drier than expected.

The geraniums (pelargoniums) seem to have fared worst. If this wet weather continues much longer, I shall have to start covering these, as well. But all plants are doing well for now. And it looks like being fine today.

Getting the Blight Protection

dithane fungicideRecent hot humid conditions ideal for the fungus diseases 'tomato (and potato) blight'. Sprayed tomato plants with 'Dithane' as a precaution. The fruit can still be harvested, when it appears.

Tomatoes Roll Their Own

tomato plant with curled leavesAs you can see, I'm still having trouble with the original tomato plant. A tomato grower told me that rolled leaves are a sign of health, especially in young plants. I don't believe it - not in these, anyway.

However, tomatoes do roll their leaves when they are too cold (Cold? Come to think of it, mine do have a bluish tinge - I Wonder. . .. It's definitely not the warmest of spots). Yet the weather hasn't been particularly cold. And 'Ailsa Craig' can be grown outdoors. And why are the younger side-shoot cuttings doing so well, without any curled leaves - even in the same sort of pot? Another mystery.

The good news is that the second truss has set some fruits, which are starting to swell. Hurray!

Corky Scab

corky scab on pelargonium leafPlants kept in soggy compost and low light often produce corky scab-like growths on their leaves. This potted geranium (pelargonium) had been left out in the rain cramped up in a container.

These will not appear on new leaves once the compost dries out.

Feeding the Growth

I don't know. Someone must have it in for me. Every time I feed the lawn with liquid feed, we get un-forecasted torrential rain (I mean, it's enough to give one a complex). Consequently, because this rain has come down too heavily to be completely absorbed, much will have run off along with some feed.

This is the start of the second spurt of growth, as far as lawns are concerned. And because heavy feeding leads to the production of less thatch at this time, and because the lawn needs building up after the dry weather, I want it growing as fast as possible (hence extra feeding). Was hoping that two feeds given at weekly intervals would have done the trick. Now not sure. Still, if worst comes to worst, can always give some more, even in dry weather. This the beauty of liquid feeding.

dollar spot disease on lawnThe lawn is showing some sign of 'dollar spot disease' (at least, that's what I think it is), as suggested by these small round brown patches. It can deteriorate very quickly at this time, as they coalesce together.

But it seems to come back quickly, especially after receiving some autumn treatment which is coming soon. Did I say 'autumn'? How time flies.

The recent liming and application of ammonium nitrogen do not help from a disease point of view. But no alternative at the moment - between a rock and a hard place. Raking should soon restore the turf. But it's still a bit too soon - and we need some time for the feed to take hold.

Insurance Cuttings

Been taking some shoot tip cuttings of the plants I want to keep for next year. Will grow these inside (if I can find the room) to give a better start. I'm not throwing the parent stock away. But you never know - it might be another cold winter (though this is unlikely; I've prepared for it).

17 July 2010

Rampant Capsid

provado sprayNew 'Provado Ultimate Bug Killer' in yellow bottle does not seem to have worked on capsid bugs on dahlias. Given them a real battering.

Dusted with 'Derris Dust', as I normally do. Problem is, most of it has washed off. Usually seems to work. Will have to see.

When to Water Pots and Containers

Don't be afraid to see the top of the compost dry out between every watering (as already outlined, this will do the roots a world of good). If you remove the plant, or stick your finger into the compost, you'll see it is quite moist below, where the roots are. Remember that plants like DAMP, not WET, compost.

This dampness need only extend to the top of the roots. Keeping it moist above this serves no value.

As a rough guide, I usually let small pots dry out about half an inch down the compost (upto two inches for larger containers (see also 'Jimini Waters Plants -Part 1')). This also helps conserve water in hot dry weather. So it protects against both extremes of weather.

Even plants which require lots of water (such as tomatoes) can usually be left until the surface is just about to change colour (since tomatoes have roots very close to the surface, you should not let the surface become completely dry).


TEST FOR WETNESS

Remember, pinch the compost between fore-finger and thumb to test for moisture. If no free water comes out, it might be time to apply water, even if it hasn't yet changed colour. Ideally, you want to see a drop of water just appear when squeezed, but disappear back into the compost when released.

You need to experiment a bit, since all composts are different.


WEIGHT IS ALSO A GOOD TEST

I prefer to pick up the pot or container to test for water content. This, along with the dryness of the surface, provides a reliable watering guide.

REMEMBER TO ADD ENOUGH WATER TO REACH THROUGH ALL THE COMPOST (water until you see excess draining away from the bottom of the pot). Assess (by the weight of the pot) that the compost has been thoroughly wetted; if it has shrunk, beware of water escaping down the side of the pot.

WATER WHEN NECESSARY, NOT BY DATE. Weather conditions and stage of growth both greatly affect water uptake. Be aware of this.

Keeping Pots Dry

COVER THEM UP

Deep containers usually make watering easy: They rarely need it, especially in a normal British summer. However, recent storms and torrential rains have caused problems, mostly because large containers are impossible to dry out in the normal fashion.

It is therefore a good idea to protect them if you can. Clear plastic bags, cut down the side, make wonderful hats. Whereas there is normally a problem with covering pots (the weight of water builds up and damages the plants beneath), this does not happen with bags. Supermarket carriers are ideal for smaller containers and most pots; secure them with clothes pegs if you have to leave them.


DON'T WATER UNLESS YOU HAVE TO

One of the advantages of leaving pots to dry out as long as possible between watering means that they can usually soak up any normal amount of rainfall.

Drying Out Over-Watered Pot Plants

What do you do if you come home to find those pots you left outside in the sun a sodden mess? Simple: Dry them out P.D.Q. But how?

Method 1

drying wet pot on kitchen towelPlace pot on top of folded kitchen towel, or similar. This will wick out that surplus which stubbornly refuses to drain away (it is held in the lower layer of compost by surface tension, irrespective of the depth of the pot).

Although we gave a general method of watering earlier, some plants, such as fuchsias, are rather sensitive and do not like the tips of their roots being immersed in soggy (especially cold soggy) compost for too long. If you use the immersion method (or absolutely drench them) as recommended, then it is a good finishing touch just to remove the excess water in this way. This will keep them growing, instead of taking a day or two to recover.


Method 2

Don't be afraid to remove your plants from their pots and examine the roots. You can do this as soon as you see them at the bottom of the pot, provided you are careful. White roots, with their delicate root hairs, will confirm that you are watering correctly.

Root distribution throughout the pot might also indicate watering preferences. For example, if the roots look much healthier at the top of the pot, this is a sure sign that you are over-watering.

roots standing on top of potStanding the de-potted plant in dry warm air will help it dry out much quicker, especially if outside (keep out of the sun). If the roots are actually brown, then these can be removed and replaced with fresh compost. In this case, you would have already noticed something wrong with the plant; it would have lost its bloom, and might already have started to wilt.

Pick up your pots regularly. You will soon get a feel for how wet the compost is in the pot. I find this the most reliable method, even for larger pots.

Over-Watering Pot Plants

Most people know plants should not be over-watered. That's the problem. Thinking that giving too much water at one time will kill the plant, they adopt a policy of 'little and often' just to be safe, usually in the form of a daily top-up.

Since more water is invariably given than can be utilized, the compost gradually becomes wetter and wetter, giving the plant a slow death by drowning. This wetting happens so gradually it is virtually imperceptible.

I want you to be quite clear about something:

Provided the plant is flowering in an appropriately-sized pot (i.e. pot is not too large and its roots occupy most of the compost), and provided there is an unblocked drainage hole(s) in the base of the pot (i.e. it can drain freely), it should be almost impossible to over-water, in the sense of giving TOO MUCH water at one time.


So WHAT EXACTLY IS OVER-WATERING?

Not all plants are sensitive to over-watering, since some are specially adapted to deal with it. However, others can be particularly sensitive.

If a plant's roots are left too long in soggy compost (or soil), short of oxygen, they are unable to breathe (respire) properly (aerobically) in the normal way. Consequently, a process called 'anaerobic respiration' occurs. Alcohol is produced which kills the white healthy roots and turns them brown. Unless detected early enough and dealt with by drying out the roots, death quickly follows.

So over-watering is caused by giving too much water over a period of time.


HOW IS OVER-WATERING DETECTED?

Wilting is a sure sign of water stress. However, it can mean different things:

  • In a WET compost, wilting is a first sign of over-watering, since the suffocating roots cannot take in water.
  • If wilting occurs in a DRY compost, the opposite is true: the plant NEEDS water.
  • But if wilting occurs in a DAMP compost (usually in hot weather), this can be quite normal. All that has happened is that the roots cannot take in water fast enough. Once things cool down, normality will be returned, so no extra water is required. Short-term protection can be offered by spraying the leaves and covering with newspaper, or similar.


Yellowing of leaves, particularly at the bottom of the plant and in warm conditions is another sure sign. Look for fallen yellow leaves on the surface of the compost.


HOW LONG CAN ROOTS BE IMMERSED IN WATER?

This depends on:

  • soil temperature (the cooler the better)
  • species of plant (bog plants can stand permanent immersion)
  • plant's water requirements (i.e. how quickly it can use up excess)
  • soil structure (affects drainage rate - not usually a problem unless extra clay is added - soil-based composts drain quicker than soil-less ones)
Most plants can cope with flooding for about 24 hours, even in summer temperatures - often up to 48 hours. Since most soils can drain in this time, over-watering should never be a problem, unless more water is applied. This is why, for most plants, it is best to water infrequently but heavily, as already outlined. This way, although growth may slow for a day or two, it will then resume at maximum rate, and all parts of the compost will have been wetted.

8 July 2010

Capsid Bug Damage

capsid bug damaged leafThese brown-edged 'pin-pricks', which develop into larger torn holes on a twisted leaf, look like Capsid Bug damage.

Sprayed with 'Provado Ultimate Bug Killer' (usually use 'Derris Dust'). Seems to have worked.

Have noticed lop-sided flowers (stunted petals on one side) before. Problem not serious. Plants seem to recover.

Funny how same pests attack same (not EXACTLY the same, I know) plants each year.

P.S. 'Provado' worked a treat on sawfly larvae.

Give Us A Break - More About Feeding

Just when you thought it was safe to grab the feed bottle . . . more restrictions. Yes. I know. And you have my sympathy. But we might as well do a proper job as half of one. Not much more, now.

It's not that there's anything wrong with what I have already told you. Far from it. It's just that I don't want you falling into the same trap almost as almost all novices.

The first thing they do upon receiving new plants is drown them in water and smother them with feed. Not realising that the wilting plants, as they have rapidly become (both too little and too much water causes wilting), are in fact drowning and not gasping of thirst, they apply even more water. Of course, things go from bad to worse. So the novice then assumes that feeding (or, rather, lack of feeding) must be the problem. On goes the 'Baby Bio', or similar - it really doesn't matter what.

Here is some more advice for dealing with new arrivals (before planting):
  • Apply only water at first, if you are sure it is necessary (it probably won't be).

  • Make sure the plant is actually showing some signs of growth before you apply any feed.

Apply no more than the recommended rate (see Feeding Recipe). You cannot make up for lost ground by applying extra.

Beware of applying feed at natural resting times, or when the plant is about to enter dormancy, at the end of the season. We all need a break, after all.

More Drought-Busters

CUT BACK FADING PERENNIALS

cut back foliageEarly-summer-flowering plants, such as these border geraniums (Crane's Bill), can be cut back now by about half to two thirds to induce another set of flowers and greatly reduce water requirements (due to reduced leaf area), provided that the soil surface is still fully covered and this cover is not too thin.


THIN OUT FAST-GROWING SHRUBS

Leafy, fast-growing deciduous shrubs quickly drain the borders of water unless kept in check. Thin them out if possible, or even consider cutting them right back. It will save lots of trips with the watering can. Don't worry. They will soon grow back.

New Pansies

pricked-out pansiesPricked out pansies into old seed trays of multi-purpose compost. I normally buy plants in the autumn for following year. These were grown from seed in garden soil. Much cheaper.

Just sprinkled seed on surface, rubbed lightly in, then watered with a hand spray to avoid capping (panning). Then placed in a light cool spot.

Dry Set Tomatoes

dry set tomato trussNot having much luck with the tomatoes. These young fruits have been like this for about a month now, set without further growth. This is a condition called 'Dry Set', caused by too little humidity and too high temperatures at pollination (recent hot, dry weather).

It looked like a good first truss, too. Cut them off to divert energy to rest of plant. What next?

Out With the Old

roots of stunted tomato plantCouldn't stand looking at stunted tomato plant any longer. Hoofed it out and replaced with one of side-shoot cuttings taken from same plant (removed before problem occurred). As you can see, roots look O.K .- Not fantastic, but O.K (i.e. white, not brown, with some growth and thickening).

Problem must be either weedkiller or a virus. By placing cutting in old compost, should tell us whether compost is suspect (planted the other of the two cuttings in new compost).

Keeping it Sweet

garden limeExcessive thatch on a lawn can be caused by over-acidity on the surface. Acid rain, ammonium fertilizers, ferrous sulphate, and breakdown of old dead material all contribute to acidity. Whilst a certain amount is necessary (pH 5.5 to pH 6.0), too much acidity restricts the activity of the micro-organisms which break down the old thatch materials; it is also conducive to moss.

For the first time, have spread about 35 grams of limestone flour per square metre (1 oz per square yard) on dry lawn surface. Hope this will help reduce thatch without raking (which destroys the turf and leaves it open to water loss).

Note: Lime must be in the form of ground limestone (calcium carbonate, not the stuff they put on walls and houses), the finer the better. Although slower acting (can take 2 or 3 years), this is the safest way. Must be careful not to add too much, as this could make lawn disease-prone. Could do with some more rain now, to help the breakdown process.

Will be interesting to see how much moss develops this autumn. I used to use 'growmore' granules (7-7-7), which contains a proportion of calcium carbonate. I never seemed to have a moss problem then. However, I have since discovered that this might be a cause of thatch, not a cure (because it contains too much phosphorus). Just when I think I've found a solution. . ..

1 July 2010

Male Begonia Flowers

Male flowers (the simpler of the two) can either be removed or left on begonias. Removing them gives slightly larger blooms. I usually remove them.

Jimini's FEEDING RECIPE

WARNING:

  • Never apply liquid feeds to dry roots. Water the plants normally first. Then apply the feed.

  • I never give too much liquid feed at one time. I imagine I am adding caustic acid which will burn the roots if I apply too much. I try to give just enough to reach about a quarter way down the pot. This way it will gradually work its way down. The root hairs will be safe, since they are mostly lower down in the soil at the tips of the roots.

  • Allow about a month to see the results. Most people, thinking the feeding hasn't worked, apply more, only to find they have destroyed their plants

  • Do not apply feed to unhealthy-looking plants in the hope it will revive them, unless you are sure they are suffering from some sort of feed deficiency.


  • FEEDING RECIPE for Bedding Plants


    I said it was simple. Here it is:

    Work about 5 mls of bonemeal into the soil, to a depth of about 10 cm (4 inches), at planting, just below the roots. It must be accessible to the roots. Bonemeal does not dissolve in the soil. And even if it did, phosphates cannot travel far in the soil.

    This should support the plant 'till flowers appear. Then give 'Phostrogen Plant Food (10-14-27)' at the recommended rate. Just feed once, for now, not weekly. Give more a month later if plants look pale.

    That's all there is to it. I said it was simple, didn't I?


    FEEDING RECIPE for Other Plants

    The system is similar for other flowering plants, certainly as far as bonemeal is concerned. We just give it in proportion. When we planted the dahlias, you might remember we added about an egg-cup full.

    'Phostrogen' can be used for all flowering plants, again at instructed rate. Note that some plants such as azaleas and rhododendrons might prefer an ericaceous feed.


    WHAT ABOUT EXISTING BEDDING PLANTS and other flowers?

    Bonemeal is safe (or relatively so). If you want to give your plants a treat, work it into the soil around the edges of the roots (this will be roughly at the tip of the leaf canopy). Just to be safe, put it a bit further away, and dig it deeper in the soil (down to about 15 cm (6 inches)) so the roots will grow into it. Again, allow some time for it to work.

    FEEDING POT PLANTS

    Same principle: But mix about 1 ml bonemeal for one inch of pot, into compost at planting. So, for example, a 3 inch (75 -80 mm) pot would need about 3 mls of bonemeal.

    At flowering, apply 'Phostrogen' in same way.

    And be careful not to burn the roots.

    Kill or Cure

    Been considering it for ages: Should I feed lawn, or shouldn't I?

    Rain decided it. Gave a full liquid feed today, in-between showers. At least it should get washed in, if nothing else.

    Problems would arise if drought returned and dried out soil before feed had had time to strengthen grass leaves and roots. Odds on our side. Being a liquid, some will get in quickly through leaves (I know they call it 'turf') and get down to roots. Rest might take longer, but it still works quicker than granules.

    Don't know if I've done right, or not. Anyhow, I've done it now. And I feel better.

    Might even start cutting again soon. If only it would grow.

    First Fuchsia

    This little fuchsia is flowering as a cutting (taken a couple of months ago) in a 3 inch pot. Really impressive. Love the colour (why can't they put the right colour on the labels?).

    Of course, I shouldn't have let it flower. It's best to remove buds to get bigger plants (plant then uses all resources for making leaves and stems, not flowers). But I couldn't wait to see what they looked like. Others will be out soon.

    Planting a Cyclamen Corm

    cyclamen cormThis cyclamen corm is beginning its fifth year. After flowering finished in May, it was dried off (as it stood, in the pot, complete with leaves), then removed from pot, and old dry compost carefully removed.

    Cyclamen is one of those plants that do not like water on their crowns ('African Violet' is another). So when planting, crowns need leaving proud of the compost. In this case, I selected the smallest pot which would contain the corm, filled it with wetted multi-purpose, then worked corm gently into surface so compost level only slightly above roots.

    Note: Compost should be wetted but not saturated (water should run out between fingers when squeezed in hand, then retract when released).

    If you have a cool humid window (e.g. bathroom) which receives some morning or evening sun, this plant is ideal. I have had best results when kept cool (kitchen can get a bit too hot). It will then flower for about eight months. And it smells gorgeous.

    Jimini Feeds Plants - Introduction

    I know I should have told you earlier. I've been avoiding it. But the truth is, I don't really know HOW I feed plants. I just have a look at them and, if they look as if they need feeding, give them a bit of what I think might do them good.

    Sometimes it works differently: I don't look at them 'till something prompts me they need feeding (it's like that thought which reminds us when we've forgotten something). Don't ask me how this works - instinct, I suppose. And this seems to work the best (now can you see why I'm worried about me?).

    This is not very helpful, I know. But it's how I do it (you did ask).

    WHAT DO WE FEED THEM WITH?

    Once, I only used two feeds: 'Phostrogen Soluble Plant Food' (used as a liquid) and bonemeal (given as a solid, at planting). However, upon beginning this blog, and on reading the recommendations of the experts, I am rather confused as to how I managed to grow any plants at all, other than poor stunted offerings with one or two flowers (reminds me of my mother's geranium, her pride and joy).

    I am so affected by this reading, I have been trying other feeding systems (not just feeding, I have re-assessed my whole growing system). And I have to tell you: so far, I am not over-impressed. The results seem no better than my own. Actually, they do not seem as good (and in the process I managed to amost destroy a pelargonium (geranium) which had been flowering incessantly for over two years (maybe even much longer)). I am not blaming these other systems; I am blaming my lack of familiarity with them. They probably ARE better. It doesn't matter. As I have said on several occasions, 'If it ain't broke . . . '. When will I ever learn?

    What amazes me is how little attention plants actually need. The less we try to help them, the more they seem to appreciate it. We should bear this in mind at all times.

    When I described watering, I tried to give you a one-size-fits-all, easy-to-follow technique - one which might not give you perfect results, but will nevertheless produce a result (and a pretty good one, at that). I intend to do the same here - soon (and, you'll be pleased to know, we are back to bonemeal and 'Phostrogen').

    Don't be impatient. We shall be feeding them soon enough. What you need to understand is, they will have been fed by the nursery with slow-release feed; some of this should still be left. There. Feel better now? First, let's look at a few things.

    WHY DO WE FEED?

    Although a complex process which need not concern us here, we should understand that feeding fuels two distinct processes:

    • the building of a strong framework and rooting system, to support the flowers and absorb the light
    • the production of flowers and seeds
    Feed contains the three major nutrients: nitrogen, phosphorus and potassium (you don't have to know all this (but it's useful), so skip the rest if you wish - go to 'Jimini's FEEDING RECIPE'). Many more elements are present as well, but these are the really important ones - for the moment, at least. So what do they do?

    Roughly speaking:

    • Nitrogen allows plant to produce protein for growth
    • Potassium hardens the plant structure, making it more disease-resistant, and gives good colour to flowers


    N:P:K RATIO

    Each type of feed contains a specific ratio of Nitrogen (N), Phosphorus (P) and Potassium (K). This has already been discussed.

    As far as we are concerned here, bonemeal will provide both the nitrogen and phosphorus to produce the framework and roots. This is usually applied at planting.

    Later, once the plants have grown, 'Phostrogen' will supply nutrients to complete this process. It will strengthen this structure and provide the potassium for flowering. Simple (it's not simple - but as far as we're concerned it is).

    Some of you might use a high nitrogen feed such as 'Baby Bio' or 'Miracle Gro' Nothing wrong with this. But bear in mind that this type of feed will produce more leaf and stems of a softer nature. We have already talked about hard and soft growing.

    This system (the type described here) is more of the 'hard' type.


    Most of us believe that we can feed flowers. In other words, by applying feed to flowering plants, they will produce more. No. Once flowering has been induced, watering is more effective than feeding. We need to watch that too much nitrogen feed does not remain, else this might induce the plant to keep increasing the framework at the expense of flowers, giving massive green plants with few, if any flowers. We want compact (but not too compact) strong plants covered with blooms of beautiful colour.