Controlling Rose Blackspot and Other Fungal Diseases

This rose bush has hardly been touched since you saw a bottom leaf in a posting on 24th June, except I have sprayed it once more and removed one or two of the lower leaves.

As you can see, the problem has been almost contained, probably by the 'Dithane'. Although one or two of the lower leaves are infected (the yellow ones), the rest of the plant is healthy and has flowered well (it is between flower flushes at the moment).

I mentioned previously that this disease (caused by a fungus) usually first appears on the lower leaves, which tend to be darker and damper and are closer to the soil where the disease over-winters. This bush is in a particularly dark and damp spot (next to the problem hosta).

Apart from removing infected leaves and spraying with a good fungicide at the first sign of disease (this is important so it is contained before it has got too great a hold), I have two strategies:

• good hygiene
• cultural control
  

GOOD HYGIENE

• When disbudding, best to deal with diseased plants last, always starting with clean plants.
• If it is necessary to touch infected part of the plant - to remove diseased leaves, for example - disinfect your hands and tools immediately to avoid contaminating clean plants. I usually spray both with kitchen bleach, then rinse after a few seconds and allow to dry. A candle flame, or similar, will sterilise a blade.
  
• Spray soil as well as underneath lower leaves. Just a light misting is enough so fungicide does not travel too far into soil where it can affect soil fungal microorganisms.
• Inspect new plants carefully to ensure they do not carry disease.

• Propagate as much stuff yourself to avoid bringing in pests diseases.
• Do not take cuttings from plants that have been recently infected.
  

CULTURAL CONTROL

Fungal disease likes constantly damp conditions. Therefore:

• Carefully remove infected leaves and burn, if possible.
• Try to avoid planting in shade. Some sun during the day is beneficial.
• Some say that a bark mulch around the plants helps, since it reduces soil splash. I have never tried it.
• Keep the bush as open as possible by cutting to outward-facing buds when pruning. Thin out if necessary. This lets drying air pass through.
• Keep plants adequately fed to maintain their resistance, but not exceptionally so. High potassium feeds (eg rose feed) can harden the plants against disease.
• Ensure plants do not touch each other, to avoid spreading pests and diseases (thin out if necessary). In larger beds, make sure you can walk between them easily, avoiding brushing against leaves, so infection is not spread on clothing.
• Avoid wetting leaves of infected plants when applying water. Apply water around roots only.
• Spray at night when insects are resting and leaf will not dry out too quickly (allows time for fungicide to enter plant). Ensure spray covers underside of leaves where pores are. Only apply enough spray to form a light mist, avoiding run-off.
• Choose plants with dark green glossy leaves.
• Yellow-flowered plants seem to be more susceptible.
• Spray with fungicide in late winter just as buds are breaking.
• Prune hard back to cut out as much diseased wood as possible.

Tomato Plants Destroyed

'Dithane' treatment does not seem to have contained the tomato blight, which was gradually extending over all the tomato plants. So these have now been destroyed and the compost soaked in bleach. I will let it weather over winter and then apply it to the rose bed next year.

I know I shouldn't do this. But I cannot bring myself to waste so much compost.

Definition of Pesticides, Fungicides and Insecticides

Reply to comment:

'What is the difference between fungicide, pesticide and insecticide? What negative effects do they have and do you have any tips for avoiding them?
By Anonymous on Rose Blackspot Treatment on 25/08/10'


Thank you for your comment. I should have clearly defined these terms for you earlier, at least as far as their use in this blog is concerned. My apologies.


Generally, a pesticide is the collective term which includes both insecticides and fungicides.

DEFINITION OF PESTICIDE

The Chemicals Regulation Directorate at http://www.pesticides.gov.uk/ defines a pesticide thus:

'The term 'pesticide' covers a wide range of products, all of which are used to control plant 'pests'.
Pesticides for plant protection purposes include:

• weedkillers (herbicides)
• slug pellets (molluscicides)
• fungicide sprays
• animal repellents
• hormone rooting powders
• insecticides
• plant growth regulators
• lawn sand treatments.'

As far as this blog is concerned, I use this definition. I think we get confused because the textbooks split plant problems into the two categories: pests, and diseases. This rather implies that pests only include members of the animal kingdom and diseases of the plant kingdom.

The problem is further complicated when we consider an insecticide as something that kills insects. In itself this is fine, but what about a caterpillar, the larva of the moth or butterfly; or a leatherjacket, the larva of a daddy longlegs (crane fly) - are these insects?

DEFINITION OF INSECTICIDE and FUNGICIDE

I think Wikipedia defines an insecticide thus:

'An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. ...'

and fungicide thus:

'Fungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores . Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality and profit. Fungicides are used both in agriculture and to fight fungal infections in animals. ...'

Although there is some dispute about exact definitions, I hope this has helped and not made you more confused.

The combined fungicide/insecticide referred to with regards to roses is used to control principally aphids, and fungal diseases such as blackspot, rust, mildew, etc.


As for negative effects, these arise because pesticides don't just kill the pests and diseases intended, but also beneficial organisms both on and around the plants and/or in the soil.

However, we need to understand that things have moved on since the early days of the organochlorine pesticides such as DDT, which did not break down in the soil, nor in the body and hence had devastating cumulative consequences through the food chain. Far more safety testing is now carried out, and pesticides are being withdrawn from the market all the time (although we need to ask: 'If the testing is so good, why do these products need to be withdrawn? Why were they released in the first place?'). We should also understand that the ordinary gardener has access to only the 'tamer' pesticides; the rest are used commercially.

In my opinion, few - if any (myself included) - persons are qualified enough to really discuss pesticides and the full implications of their use. We are somewhat in the dark as far as certain aspects are concerned; although some of their effects are plain for all to see and opine about.

What I have done with the blog is to point out opinions as they have arisen with regard to descriptions and reasons for various operations performed in the garden. It might be best done this way. It wasn't intentional; just the way it worked out. And, of course, I also try to show how to both minimise their use and use them more safely (at least I hope that's what I do).


As far as tips are concerned, you have touched upon the crux of the blog. Part of my growing philosophy is to produce a garden which will work with minimal, and preferably no, use of pesticides. As stated recently, to a large extent this has been achieved. But to extend the diversity of the blog I have taken on new projects, and I think it is from these that the pest and disease problems have arisen (though to be fair, I did have some pests before).

Very soon I shall be doing an analysis of the year's operations, and from this you will see my proposals. They are too extensive to detail here; although you should know that they are based upon cultural techniques rather than control. I'll explain what I mean by this, shortly. Watch out for the posting. Coming soon.

Best wishes,

Jimini

Lawn Action in August

Reply to comment:

'What action do you take in August?
By Anonymous on Moss in Lawn on 25/08/10'


Thank you for your comment. As far as the lawn is concerned, if you look in the blog archives, you will see that I posted a 'Moss Alert' on 6th August which alerted readers to the dangers of moss getting hold at this time of year. If you look at the post, you should find links back to other lawn articles which will outline moss and other lawn jobs. Also, if you look at the categories at the side and click the 'lawn' link, you should find all the lawn posts.

There was also a lawn posting yesterday which was written before I read your comment.

The Lawn in August

August is in many ways a strange month, certainly as far as a lawn is concerned. Temperatures are still reasonably high, and provided there is sufficient moisture in the ground, growth should be quite strong. It is therefore a good opportunity for a lawn to recover from the hot often dry summer months (especially this year). High nitrogen (these should also contain some phosphates and potash (P and K)) feeds can be given up till the end of the month, which will really help the lawn recover.

However, there is also a downside. Overnight dews combined with high temperatures provide an ideal breeding ground for fungal diseases. You will see that I have had problems with 'Dollar Spot' disease (apart from the blight on the tomatoes). This has been largely dealt with by raking it out somewhat prematurely. This operation has been mostly successful, though there is still a little bit left. This disease is not fatal (it only affect the finer grasses, anyway); it merely disfigures the lawn for a while.

And of course, there is moss, the bane of my life (one of them). Warm dewy nights are also ideal for spore germination. Moss is sneaky and can suddenly appear, as if from nowhere, as I am sure you are well aware. So I really do advise you to be on the lookout for it.

I limed my lawn this summer (see 'Keeping it Sweet') to help with my moss problem. And, touch wood, this seems to have worked, at least so far. Usually I have had moss before now. But the lawn seems clear. Hope I haven't spoken too soon.

Removing acidity (by liming), and improving drainage, can each help tremendously with the moss problem (liming is best done early in January).

If you look back at the summer lawn posts, you will see that I spiked the lawn to aid water penetration (look under 'lawns', 'watering' and 'water conservation'). Water penetration can be prevented either by a thatch on the surface or by compacted dry soil beneath. Spiking, or pricking punctures the surface to allow the water through it.

A good technique is to go further than this and push a fork further down into the soil (as I did in the summer). If it is wiggled around, in the right conditions, it will break up compaction. But there is a downside: The soil needs to contain the right level of moisture, otherwise it can do more harm than good (this will be explained soon). Furthermore, because it breaks the root system, we need to be sure that the grass can recover quickly enough by growing new roots. For these reasons, I do not recommend deeper tining at this time (best to wait till further in September). Stick to pricking, spiking or shallow tining if you can.

If the soil is really hard - so hard that water just cannot penetrate (as it has been this year) - I push the fork deep into the soil just to make a hole, but do not wiggle it. This way, root damage is minimised, and the water has more chance to get deeper down to where it can begin wetting the lower levels.

The other thing which is good is Hollow Tining (provided the ground is not too hard), which I briefly touched on in a previous post.


If there is one thing I want to teach you about growing, more than any other, it's that we need to do things when the plant dictates, not the calendar. I know there are good arguments for doing things at the appropriate time. But nevertheless, this should be dictated by the plants. Times have changed. Seasons have changed. Methods and opportunities have changed. Equipment has changed. It's all changed from how it used to be years ago. We need to bear this in mind, yet still consider the wisdom from the past.

As the autumn progresses and the nights draw in further, the lawn detects this and changes its growth pattern from producing leaves to producing roots for next year. I have just given my lawn a feed which should be enough for leaf growth this year and give the grass a good start into the autumn when we can concentrate on the roots.

So, to sum up, make sure the drainage is good on your lawn and that water can penetrate down into the soil, ensuring any winter rains can get away without waterlogging the surface. Get on top of the moss, rake out any thatch and dead grass if necessary.

I hope this will be useful.

Best wishes,

Jimini

Tomato Stem Bottleneck

Apart from the suspected blight, the reason the fruits were so slow to swell on the tomato plant might be something to do with the stem thickness at the base of the plant.

This photo (sorry, not a very good one) shows how it looked at the beginning (the thin part) and how it looked once it was cared for (the thicker part). I am surprised at this. I thought it would have thickened all the way down. Apparently not. But it does seem it could be at least a part of the problem.

Lawn Update

The lawn has now almost fully recovered after its recent raking and is growing well. At the end of this month, we should stop feeding high nitrogen summer feed, ready to begin the autumn programme. We shall then be using 'Phostrogen All-Purpose Plant Food' (14-10-27) - or an autumn lawn feed - since it is high in potassium which will harden the grass against further disease, and also against frost.

It is important not to go into winter with too much lush green growth (caused by high nitrogen feeds), yet we should feed enough to allow the grass to build up a food reserve for the winter.

Autumn treatment will begin next month.

Water-Damaged Fuchsia

It soon becomes obvious all is not well with our plants. The dull tips of these fuchsia leaves indicate problems: probably water damage through waterlogging. The plant was left outside in a pot and became thoroughly soaked for too long (a couple of days). I should have protected it, but I didn't.


Even a 180 mm (7 inch) pot is easy to remove (by inverting) to examine the roots. The brown stains confirm water damage to this 'Triphylla' fuchsia. This could be cut away and replaced with fresh compost, but since it is nearly the end of the season, and I will be doing this then anyway, I'm leaving it for now. It is not too badly damaged, and should recover. It will just need watching to ensure it doesn't start wilting.

Tomato Blight Update

Further downpours have produced more blackened tomato leaves: almost certainly blight. Leaves were immediately removed and burnt.

I am not absolutely certain the problem is blight, but it fits. Both potato and tomato blight are caused by the fungus Phytophthora infestans.

The RHS 'Pests and Diseases' outlines the necessary conditions as:

'. . . consecutive 24 hour periods, each with a minimum temperature of 10 deg C (50 deg F) and each with a minimum of at least 11 hours where the relative humidity is 89 per cent or more'

I am not sure whether the 'Dithane' has stopped it or not. Of course, I should really have destroyed the whole plant. But there seems little point, since it must have arrived in the air; and if I grow more tomatoes next year, I will choose a blight-resistant variety (nevertheless, I will still give everywhere a good disinfecting, before then).

I suppose I am reluctant to lose the few fruit which are there. I just want to wait and see how things develop.

More Caterpillar Damage

The hole in this fuchsia bud is caused by a caterpillar produced by a huge brown moth. It lays just one egg which hatches into the caterpillar, capable of immense damage and usually extremely difficult to find.

Holes in the leaves and black pellet-like droppings are other signs.

Tomato Blight?

I think the black blotch on this tomato leaf is tomato blight. I first noticed it three days ago, but didn't spray immediately as I should have done because I seem to have done nothing but spray this and that over the past month or so. This is why I recently reported the doom and gloom: It's not the pests and diseases which are causing it, but the constant use of chemicals. I don't like using them, and never have; I am all the time seeking ways to avoid them.

Up till this year, I had got my garden relatively free of these problems (I'll explain how later). But I suppose it's the influx of all the new stuff which is causing the trouble. Now am having to start all over again.

I had thought that the tomatoes were beyond hope. I didn't believe those who told me that some varieties of tomato rolled their leaves naturally. And I don't know why I didn't do a 'Google' search for tomato leaf roll. However, I did one yesterday, and found plants which resemble mine. Apparently the problem is stress-caused.

This bottom truss of the problem plant has 26 set fruits (some are still tiny). They had been hanging around, not growing, but have recently started to swell. There are set fruits on the truss above, as well. And we have already seen that one truss has been discarded due to 'dry set'.

To be honest, I had more or less given up on the tomatoes; I had taken my eyes off the ball. Now I have decided to take interest once more.

We can leave the moral issues of whether spraying is necessary or not. This blight is the same sort of thing which caused the dreadful Irish Potato Famine; IT DEFINITELY NEEDS NIPPING IN THE BUD, STOPPING IN ITS TRACKS.

Have sprayed again with 'Dithane', probably too late. I am now monitoring the situation very closely. Will keep you informed.

Getting the Light Right - Part 2

How We Determine a Plant's True Light Requirements

Although our plants are in roughly the right position (we hope), how do we really know?

Simple. We watch them - they 'communicate'. They move themselves around until the light fits just right, just as we do on the beach. This movement is called 'phototropism'.


LEAF MOVEMENT

If light is too LOW

This mint has gone leggy (become etiolated, stretching vertically) and is also bending towards the light. It is thus clearly asking for more light.

Plants also grow larger leaves in low light; it helps them produce enough food. This is why it is best to keep coriander leaf (cilantro) out of too bright light.



If light is too HIGH

We have already seen how a begonia turns its leaves away from the sun. This fuchsia is doing the same thing. I'm not sure if you can see, but the leaves are all different sizes, reflecting to some extent the different light levels to which it has been exposed.



ROOT MOVEMENT

Roots exhibit negative phototropism. That is, they move away from the light. You would have seen this with your coriander roots, although I didn't mention it at the time.

Summer Waterlogging

I think we know by now that roots need air, as well as water. I don't want to bore you any more. But it's worth bearing in mind just how sensitive plant roots become to lack of oxygen at higher temperatures. In other words, you need to watch those thunderstorms.

This yellowing fuchsia leaf is showing the first signs of chlorosis caused by being left too wet for too long at too high a temperature. The lower leaves are affected first; these are quite often found lying on top of the compost, usually a sure sign of either low light or of waterlogging.

As with most plant ailments, the first reaction must be to move the plant to somewhere cooler (but light), then dry it out. If you reach it in time, the problem should end there.

If in doubt about the weather, leave the watering, if you can. I usually get trouble when I have watered in the morning and it pours down whilst the pot is still wet - that's what happened here.

It's All About Light

Green plants cannot function without light. They need it for photosynthesis, the process by which glucose is created from water and carbon dioxide. This simple sugar glucose can then be eventually combined with nitrogen ions to create amino acids, the building blocks for proteins.

So photosynthesis is the dynamo which allows the plant to function and grow. Although artificial light (but not really tungsten, or household light) can be used, the principal source is SUNLIGHT. This is important to the plant in two ways:

• It's INTENSITY affects the rate a plant can grow (assuming no other essential factor is limited)

• It's LENGTH (the length of day, or photoperiod) can affect reproduction (time of seed germination, flowering, food storage, and senescence (death))
  

Since light is so important, why haven't I mentioned it before? Because I find that novices have more problems with watering and feeding.

Getting the Light Right - Part 1

Plant Labels Only A Guide

At one time, assessing a plant's environmental requirements used to be some sort of arcane art known only to the few. Not any more. Nurseries have obliged by providing cultural information with their plants (it's in their interests that we keep them alive). Labels tell us everything we need to know: How much water and light they require, what type of soil, and often much more. How can we go wrong (do I really have to ask?)?

Well, apart from the fact that most people don't even read the labels - or do read them but ignore what they say because they inform them the plants are completely unsuited to their chosen location - things never seem to work out how we thought they would (do they ever?). Very seldom can we accommodate a plant's exact requirements.

Also, many find labels confusing. Half a sun (those arcane arts again) might not mean much to Great Aunt Bertha who remembers how the gardener seemed to make things so simple to her childish mind . . . she just wants it in plain English like it used to be.

And does it really matter if we only have a quarter of a sun and not a half? Probably not. My experience is that plants thrive in the oddest of situations, for no apparent reason and in complete defiance of any manner they are supposed to (another one of those mysteries). So we should not take labels too seriously; they are only a guide - and to be fair, usually a pretty good one.

But just in case you're wondering, what does half a sun actually mean? Are you there, Aunt Bertha?

• Full White Sun - sun for most of the day with little shade (when it's sunny, of course)

• Half Sun or Partial Shade - sun for about half the day, or dappled shade (think of woodland on a sunny spring day - can you smell the bluebells?)

• Full Black Sun or Full Shade - full shade with little or no sun

Take time to watch your garden light as the sun moves around throughout the day, especially your chosen spot. But remember: those labels are not carved in stone.

The Good News

After reading through the past few posts, my heart in in my shoes. Nothing but doom and gloom. Or so it seems. But things aren't quite so bad, you might be pleased to know. It's just, I thought some troubleshooting might be helpful (what? you mean there's more?), and I'm one of those persons who likes to get the bad news first. Anyway, let's change the record. This geranium (you saw a leaf of it in March) is now really getting going (the plant is about 10 months old).

This is good news: I was worried I might have overdone it a bit on the watering recommendations. But the 'proof of the pudding . . .', as they say. 'What can't speak can't lie', and all that . . .. Well, it can; you'll just have to take my word for it. You do, don't you?

The only thing I would say is, I have given it more feed than normal (which, as you know, is next to none). It's been fed with 'Phostrogen', every other watering. It's rather difficult to explain, but it has received about one third the recommended feed in total (i.e. about 2/3 of the dose recommended for every watering, but given only every other watering). Eh? (why can't I just keep things simple?) So it's been softer grown than normal. But I needed some fast results. I'll explain how and why, soon.

And it's not just the geranium. There have been other successes, too. Some have been surprises (well, at least I'm surprised). Plants which I thought might keel over have suddenly performed well . . ..

Unbalanced Fuchsia

Nine weeks after the last stopping, this fuchsia is in full bloom, The first flowers appeared bang on time, at eight weeks almost to the day (8 weeks for singles; 12 weeks for doubles). But things have never gone quite right - It hasn't grown evenly and has always looked unbalanced.

If you remember, it was unbalanced from the start. Although I reduced the size of leaf on one side to try to even things up, this didn't really work: the stronger side kept strong.

It has been pinched out (stopped) 3 times, after each 2 pairs of new leaves. Since we started with 4 shoot buds (one per leaf), there should now be 256 flowering shoots (4x4x4x4). Some seem to have got lost somewhere - I think that's why the plant looks patchy - but I can't see where because the foliage is too dense.

Still, I suppose it doesn't look too bad. But I'll start with a more balanced plant in future.

Pruning a Fallen Hydrangea

Think the second feed did it (we'll ignore the torrential downpours) - reduced a gorgeous hydrangea to this fallen state. But it was good whilst it lasted. Now we need to thin it out in such a way as to avoid destroying next year's blooms.

The standard way to prune shrubs which flower in the second part of the year is to cut them back to a healthy bud in late winter/early spring, as soon as the danger of severe frost has passed and the first glimmers of growth are showing.

Problem is, if hydrangeas are cut back too far, they don't flower that year. So, apart from taking about a quarter of the stems back to the floor this spring, I have been reluctant to cut the rest too much. Gradually, over the years (it's now 10 years old), it has got taller and taller. Now it's too tall. I have to do something, if only thin it out and get it back on its feet (the blooms are holding too much water, too much weight).

I read that if mopheads can be cut back early enough - whilst they are flowering but before the new flower buds are set - they will still flower the next year. The recommended time is July to early August. But the blooms had hardly opened in July, and some are still growing (most are about 20 cm (8 inches) diameter), that's the problem.

So I might be too late; there are already buds developing on the stems (purple on old wood and green on new). Can't tell if these are flower buds, or not.

Anyway, I have now thinned it out by cutting back about half a metre (18 inches) to a healthy bud.

Earwig Damage

The ragged holes on this dahlia flower is earwig damage. I found one hiding in a fuchsia flower last week. Don't think I have ever stamped on anything so hard - so there's no chance of a photo.

The recommended treatment is upturned flower pots filled with hay or straw and supported by sticks next to the flowers. I don't happen to have any hay or straw, but an old tea towel, or similar, can be used.

Update on Geranium Blotch

Am now having second thoughts about last week's article on 'Geranium Blotch'.

Might just be 'fungal leaf spot' here. Still not fully sure. But best to bear this in mind. If it was leaf spot, the 'dithane' seems to have worked, anyhow. But, then again, we haven't had any really bright and muggy rain showers.

Moss Alert

This is the time of year (especially with the wet weather) when dormant moss spores sitting in the lawn spring to life and establish themselves unnoticed. By the time you realise moss is there, its removal will leave an usightly mess - and a much much bigger mess if you ignore it until next spring, as encouraged.

Best be aware and nip it in the bud as soon as you see any sign at all (get down close and look carefully). If moss is found, I suggest spraying full lawn with ferrous sulphate as we did earlier. You'll be amazed at just how much moss is actually there (its now black colour makes it stand out). But by treating it this early in the season it can be raked out, if necessary, and the turf will have time to recover before the winter. And you will have that lovely rich green colour from the iron salts.

If you're lucky and you don't have much thatch or dead grass, you might not even need to rake, not yet anyhow. The grass should soon cover up the dead moss which will just rot down. Never mind about the spores; as stated elsewhere, normal mosskillers do not kill them; there's nothing you can do about it.

Lawn Recovery

After last feed, lawn now greening up and growing well. Problem is, it contains unsightly dead patches from 'dollar spot disease' and hot dry weather.

Could just leave it alone and continue cutting at about 2.5 cm (1 inch); it would eventually green right over. But I'm impatient. I don't want to wait. I want it fully greened right now (yes, I know this is not possible, but you get the idea).

Fortunately, the box of lawn management tools contains tricks which can work acts of wonder on any lawn. We're going to use one of them here - a little earlier than intended (I said I was impatient). What's that? What is it? - the RAKE.

THE TILLERS' TIME HAS COME
Many people are reluctant to rake their lawn because it damages the turf too much. It does. But what most don't know is that the time of year makes a huge difference to the effect:

• In spring, the the lawn takes some time to recover from the thinning out.
• However, in autumn, raking has the opposite effect - IT CAUSES IT TO THICKEN.
  
  Lightly raking a lawn (as we did in late spring) in autumn causes it to tiller. i.e. It induces side shoots to grow out from the main stems of the grasses. So instead of having one stem, we have a clump of stems. And it's this which causes the thickening. Good, eh?
  
  This trick is so good it has to be seen to be believed. I usually wait until after the first moss treatment so I can rake out the unsightly dead moss as well. And I have to be honest: I really should wait now; after all, it's only another couple of weeks.
  
  My experience is that this thickening effect only happens once; it's never as good the second time. So, if you can, get your moss sorted out first, then do the raking (only lightly, remember). This will give the turf time to thicken before winter - something to be proud of, not ashamed of. As for me . . .. Now, where's that raker?

Snailed Again

If you are greeted one morning by huge chunks missing from your favourite plants, you can be sure of one thing: They're at it again, those pesky pests. Caterpillars, slugs and snails all do this sort of thing to plants. Here is a snail-damaged dahlia leaf (the curly line is a leaf miner, which isn't harmful).

Snails always seem to be most active at this time of year, especially in a wet summer. I normally attack them sooner, but because there are a couple of toads in the garden I have been reluctant to use pesticide. Spraying the leaves with metaldehyde usually helps, though nothing seems to deal with them to my satisfaction.

Snails are a real problem on damp ground covered by dense vegetation - the perfect place to live as far as they're concerned. They lay eggs in the soil which easily survive over winter (the eggs cannot survive for long in dry soil; this is why cultivation, to expose the eggs to the sun, in sunny weather helps keep them down).

Normally, snails just affect the wet places. But this year they are all over the garden. And they have become hard-faced, coming out in broad daylight, not just in darkness. Fortunately they only work above ground where they can be seen; they do not affect the roots.

If this wet weather continues, I could well find myself groping around the garden at night by torchlight. We'll have to see.

A Cut Below Average

This geranium (pelargonium) cutting was much larger than normal when taken 7 days ago. But I took it for a reason: A larger cutting, especially if branching has already begun, moves on the growing process by weeks, if not months.

Pot geraniums grow very slowly, so getting more growth before the start of the next season allows the plant to grow larger and produce more flowers. It effectively lengthens the growing season.

Growers usually remove most of the leaves on new cuttings, except for one or two, to reduce the demand for water from the as yet un-rooted stem. But plants are clever. If their systems are overloaded, they usually take parts out of commission to reduce demand. In this case, the lower leaves (about half the total) immediately drooped (stopped functioning) to cut down on water loss. However, as you can see, they have all come back except for one. But note how some are still turned up to protect the young plant from too-strong light. These will eventually flatten when the roots are adequately formed.

The cutting should now survive without further loss of leaves, putting it months ahead in the growing stakes. I wasn't sure it would survive; I'm glad it did. I'm going to take more cuttings this size in future. And, just to recap, this was placed into damp soil just 7 days ago without any cover of any kind and without using rooting hormone.

Geranium cuttings will survive like this outside in the garden soil, as well. After removing the shoot tips to induce branching, don't throw them away; stick them in the soil to get new plants. They will nearly always survive. At least, this is my experience.

See also: 'Taking Geranium Cuttings'