Organic garden pest control

Pests in your vegetable garden

If your vegs are covered by nasty, green, crawly things, don’t panic!

The GardenAdvice team are here to help you with words of wisdom on bug control.

The first thing you need to do, is get a handle on which are the good guys, and which are the bad guys, in your organic vegetable patch. Apart from the obvious slugs and snails, which we all know about, I can only cover a few other common ones here in detail here. So get yourself a good bug and critter book! Also check out our database! It would be easy once you’ve spotted something nasty munching the lettuces, to behave like Mr MacGregor and blast away with the chemical version of a shotgun! But consider not only do you and the kids have to eat the lettuce, but long-term you’re only storing up problems for yourself in the future.

Many chemicals are non-specific, so they can kill the good guys as well as the bad ones. And by continually using chemicals, some of your nasty bugs may become immune. Just like the superbugs we’ve all heard about in hospitals, which defy all anti-biotics! So, what to do then? I reckon once we know who the bad guys are, we should try to prevent them from becoming such a problem in the first place!

For Advice on more serious pest problems such as pests in your house or office try the Bon Accord Pest Control website

First, we need to look at how we “garden” our veg patch. For example, at the end of the growing season, ensure you tidy up all plant debris on your onion plot. Followed by a good dig over or a rotovate. This will ensure populations of the onion fly maggot cannot overwinter so easily because they’ll either get killed off by the frost, or eaten by the birds.

It’s also very important to rotate your crops. Using the example of the onion again, if you plant in the same spot year after year, diseases such as white rot, as well as bugs like the horrid onion fly, will become more and more of a problem. So, even if you’ve only got a tiny veg plot, make a plan every season to help you plant next year. A little extra work, with a pencil and paper, could save you heaps of trouble in the future. You should also take care not to plant members of the same family in the same place. For example, did you know the following are related: peppers, tomatoes, spuds [potatoes], as well as aubergines (nightshade family)? As are cabbage, brussel sprouts, mustard greens and cauliflowers (brassicas). And not forgetting cucumbers, melons and courgettes (cucurbits).

So, you may find it helpful to plant your plant ‘families’ in groups or blocks. To make your rotation planning easier. But, if you, or your neighbour, are having a particularly bad year with bugs or disease spreading through a particular crop like wildfire, you may want to break up your planting a bit. With rows, or part rows, of unrelated flowers or veg. This is called companion planting. 
There are also barrier methods to consider. No, Mrs, not that kind of barrier!! What I’m talking about are floating row covers, to keep off carrot fly, and wire fencing buried three feet deep around the entire veg plot to keep out rabbits. I speak with very recent experience on this one, having had cute, fluffy bunnies eat my carrots, onions and garlic!! And now for some specific bugs and diseases:


1: Slugs And Snails
That’s an easy one to start, at least we all know what they look like. With slugs, believe it or not, it’s the little tiny grey ones that do the worst damage, while the great big ones mostly live on dead organic matter, such as rotting leaves. Back to the little grey numbers, there are several ways to deal with these blighters:
* You can pick ’em off by torch light, this may sound bonkers, but they do mostly feed at night. 
* You can sprinkle ’em with salt (bit cruel that one!). 
* Use beer traps placed level with the soil, so they can drown in oblivion. 
* Encourage critters [animals] like toads, hedgehogs and ground beetles, who’s favourite snack is a slug or snail. 
* Or the combination of your choice. 

I prefer to pick them (I do it by day) and encourage the critters.
2: White Fly

Although this is mainly a greenhouse [and hydroponic] pest, it’s certainly worth a mention because once you’ve got it it’s a real bugger to get rid of. A whitefly attack reduces plant vitality, causes premature leaf drop, and may result in the demise of your favourite plant. Yes, that one granny gave you for your birthday last year! Not to mention a nasty black mould, which results from the ‘honeydew’ excreted by the little darlings. (Yuck!) Now to the control of these little blighters!

Provided you don’t have a major invasion, you could allow a tiny parasitic wasp, called Encarsia Formosa, to come to the rescue. These are available from some garden centres and seed companies. The little wasps lay their eggs in the white fly larvae, and that’s that. But, if you’ve got a major outbreak of white fly, then the Encarsia won’t be able to cope, as they don’t multiply fast enough. So you’ll need to take more drastic action and give your conservatory or greenhouse a really good clean up. If possible, you should first move all of the plants outside and give them a thorough spray with insecticidal soap or growing success bug spray that contains natural plant oils(don’t forget under the leaves). Next, give the greenhouse, or conservatory, a really good spring clean. (Even if it’s July!)

Scrub the glass well, and make sure you get into all those nooks and crannies. You may, as this will hopefully be a one time major clean up, like to use something strong such as Jeyes Fluid or washing soda to get things really clean! Or, if you prefer, you can always use washing up liquid or soft soap, and scrub a bit harder! Next, if weather conditions allow, keep your plants outside another couple of weeks, spraying with soap twice a week. When you finally bring them back in, you may still see a few white fly wizzing about. Now is the time to introduce your Encarsia. These little wasps will keep things under control from now on.
3: Aphids
These little charmers are similar in many ways to the white fly. Except they attack a much wider range of plants, come in a variety of colours, and misbehave both in the greenhouse as well as in the veg plot! Aphids transmit plant viruses, cause stunting and deformities of leaves and stems. And similar to the white fly, they also produce ‘honeydew’ causing a black mould to form on the leaves. This reduces a plants ability to photo syntheses. There are many things you can do to fight aphids.
* You can wash ’em off with a hose. 
* Spray ’em with soap, or growing success bug spray that contains natural plant oilsas with whitefly. 
* Attract the beneficials to help. Such as ladybirds, hoverflies, and lacewings, by growing flowers, such as marigolds, in the vicinity. 
* You can also encourage blue tits, and other insect eating birds, by putting up boxes for them to nest in. 
* And finally, if you’re not squeamish, you can always squish ’em with your fingers!

4: Fleabeetles
These aren’t the leaping little beggars that bite your dog or cat. They’re actually a tiny little beetle that has a preference for making lace curtains [shredding] from your Brassicas!! When you touch the cabbage leaves they ping off just like the regular fleas, only these won’t bite you! A good weapon in this instance is horticultural fleece placed over your brassicas, as soon as you transplant them outside; a floating row cover. 
* You can also try mixed planting, to confuse the little suckers. 
* Cultivating the soil regularly to destroy eggs and larvae in the soil. 
* Giving your plants a midday shower with the hose, as they’re most active then. 
* Again Companion Planting, to attract the good guys. 
* And finally you can now buy Beneficial Nematodes, which you can water in to your soil.