Allotment

Pests & Diseases – Keeping Calm And Carrying On

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Within this seemingly green and pleasant allotment lurk a plethora of pests and diseases….

It’s surely a natural tendency most of us have to only post the best bits of our lives on social media – not necessarily in order to deceive others into thinking we’re perfect but because the successes are the things that excite us the most, and therefore the things we most want to share with others. I’m certainly guilty of this with the pictures I post on Instagram – I’m not likely to post a picture of some underwhelming bolting turnips, nor would I expect that anyone would like to look at a photo of such a thing. This does, however, lead to a glossing-over of some of the problems and failures that every gardener experiences, so in an attempt to redress the balance I should like to share some of our most troublesome pests and diseases, and the methods that I have used to at least attempt to control them.

I have come to accept that pests and diseases are part of the ecosystem of any garden. The idea that they are problems which must be eradicated is unrealistic and unhealthy – natural predators (eg. ladybirds, frogs, birds) require pests (aphids, slugs, caterpillars) to eat in order to survive. Eradicate the pests and you eradicate the predators too. Our job is to act as ‘ecosystem engineers’, helping to keep the balance right in the artificial space that is a garden, for example by creating habitat for predators (a pond, a log pile), growing sacrificial plants (nasturtiums for the caterpillars, instead of them munching the brassicas), and intervening only when a particular pest is starting to inflict too much damage. On another level, I also think it’s worth remembering that pests are still ‘wildlife’ and as such can be quite fascinating to watch whilst they destroy your crops…. Watching ants ‘farming’ blackfly on your broad beans is highly entertaining, and this certainly offsets any reduction in yield as far as I’m concerned! Here’s a description of our biggest ‘problems’ – if anyone has any tips on how to keep any of the following under control then please do let me know:

Cabbage Whitefly

Not cabbage white (caterpillar) which we mostly avoid with the use of netting, but cabbage whitefly which is an aphid…. This sap-sucking pest loves all our brassicas. The main problem with them is that they excrete sticky, sugary honeydew which then encourages a white-ish mould to grow in patches on the leaves of the affected plants – still edible but not very appetising.

Remedies tried so far: I occasionally give the plants a good spray with the hose, causing the whitefly to all jump up into the air in an aphid cloud…. I’m fairly sure they just climb straight back on again, but it feels very satisfying. Other than that I have just put up with the white patches on leaves (its less of a problem on Brussels sprouts and broccoli as these get trimmed). I am wondering about using some kind of very fine enviro-mesh on the plants next year, though I suppose it only needs one aphid to find its way in and then they’ll be back with a vengeance!

Pigeons

Still on the brassica theme, I worked out early on that if I actually wanted to eat any of our kale/broccoli/sprouts myself then netting them was essential (which, if you’ll excuse the pun, killed two birds with one stone by protecting against both pigeons and caterpillars). The same goes for strawberries, and I’ll be netting our red & white currants next year as the pigeons got them all this year. They’ve also taken a strong interest in our peas this year, pecking the leaves away.

Remedies tried so far: Just netting, which is fine for brassicas but not very practical for peas. Opinions on the worthiness of scarecrows/bird scaring devices welcome. Shotgun often threatened but never seriously considered.

Powdery Mildew

And now, to the fungal diseases. These are perhaps harder to justify as being an important part of the ecosystem, though of course fungi and bacteria play a vital role in the soil so I have never used any fungicides. I think allotments can be a real breeding ground for fungal diseases with everyone growing the same sort of crops in close confinement so I highly doubt a spraying regime would do very much anyway. Powdery mildew affects a large number of our plants – herbaceous perennials such as Scabious early in the year and then annuals like sweet peas, edible peas, courgettes and squash start to succumb in late summer. It attacks plants when the soil is dry, so my aversion to using the hose unless absolutely necessary is probably partially to blame. My main problem with it is that it’s unsightly – it doesn’t seem to stop the plants from growing and producing.

Remedies tried so far: I have pledged to be a little more generous with the hose next year for susceptible plants. We’ve also tried spraying diluted milk on affected leaves (something to do with fatty acids attacking the fungus), but you have to be pretty thorough, spraying both sides of the leaves in order to make much of a difference. Other than that I just keep calm and carry on.

Rust

Leek rust (affecting all alliums, but garlic in particular for us) is ubiquitous and is something I just ignore for the most part. We still get good harvests of onions, garlic and leeks, and I even compost affected foliage as I read that it needs to be on living plant material in order to survive.

Beetroot rust is a new one for us this year, affecting a whole bed of beetroot which perhaps were planted too closely to allow good airflow. It caused the leaves to die back, and while the roots were an OK size it certainly affected the yield.

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Beetroot harvest – a mix of sizes, but the rust meant that the small ones weren’t getting any bigger.

Remedies tried so far: As mentioned, leek rust doesn’t seem too destructive, but I’m not quite sure what to do about the beetroot rust beyond giving them a wider spacing next year.

Raspberry Cane Blight

Another new one for this year (how exciting!), and again possibly helped by lack of airflow so I think I’ll thin the canes more next year. It has caused dieback for some of the canes, but the majority look reasonably healthy and are currently chucking out plenty of fruit, so hopefully it won’t get worse.

Remedies tried so far: I’ve removed affected canes as I’ve noticed them, and will thin next years’ canes when they appear. I’ve noticed it on other people’s raspberries on our site too so I don’t expect it will be possible to get rid of it. There aren’t even any fungicides available to home gardeners to treat this disease even if I was that way inclined so it’s definitely just a case of carrying on.

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Broccoli from whitefly infected plants, courgettes from mildew covered plants, and raspberries from blighted canes…. I don’t seem to have dropped dead yet!

So there you go – a snapshot of some of the less instagrammable aspects of our plot. If you have any remedies for the above that you have found successful then let me know! Bragging about our delicious tomatoes will resume next time….

 

 

 

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2 thoughts on “Pests & Diseases – Keeping Calm And Carrying On

  1. D > Oh dear, that’s quite a lot to contend with. Even so, you seem to get worthwhile results, and in the end that’s all that matters, isn’t it – that the outputs justify the inputs. I now realize we get off very lightly, as far as pests and diseases are concerned: but that’s fortunate because the strong and persistent winds makes any kind of mesh or netting quite impracticable – it’ll get thrashed to pieces, and the crop destroyed with it.

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    1. Indeed, quite an impressive selection I like to think! Many of these are an inevitability on allotment sites I think, so making do is the only option short of dousing with an array of chemicals…. On the plus side, we’re not too bothered by slugs and I’ve never seen potato blight here. Do you get deer in your garden, or does the wall keep them out?

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