Garden pests 2

No more garden pests: Hostas with no slugs
Sissinghurst Castle Garden – Hostas free from slug damage; image: Michael Garlick; Creative Commons Attribution-Share Alike 4.0

More garden pests

The way to tell if your plants are being eaten by slugs and snails is to look for mucus around and on the plant. Slugs and snails are much more active in wet weather and can completely demolish a small plant in one night. There are several ways to deal with slugs.

How to get rid of slugs

The most obvious way is to ensure that they have no place to live and not be seen. When clearing out a forgotten corner of the garden (eg a pile of old pots or a compost bin) you will find lots of them. How you dispose of them is up to you. A friend of mine painted a white spot on all her snail shells. Then she took them 20 miles away and let them go. Some of them came back!

Slugs and snails adore yeast and beer, so you can attract them into containers with a liquid containing either of these. Sometimes they will die, but you may still need to dispose of them. There are commercial products to kill slugs and snails which do work, but then they are banned after a few years. This is maybe because they kill other animals and birds.

What slugs like to eat

Some plants, such as hostas and lettuce are very attractive to slugs and snails, so you have to grow them somewhere that you can see what is happening. I tried growing them in pots with copper tape around the pot, but I never found that it worked. When I plant out individual plants, like lettuces, I usually put a cut plastic bottle around them (cut the bottle into three) so that slugs cannot crawl in over the sharp top.

Another thing I have done in the allotment is to dig a small pond. This has certainly attracted frogs, toads and slow worms. These are said to eat slugs, but I like to have them around anyway. The slow worms tend to live under the pond lining, but I sometimes find them in other places. The tadpoles and frogs appeal to the local children.

Underground pests

As long as you have plenty of worms, your soil will grow things. I have been in places where there are no worms, but it may be because it is too dry for them to be anywhere near the soil surface. Worms are working all the time to give you good soil, so breeding worms in wormeries or in your compost heap is a good thing to do.

Unfortunately, not all the creepy crawlies that live in the soil are good. If you grow potatoes, you will know that some of them get into your spuds and make them unpalatable. These include wireworm and eelworm, but the slugs often get in there first. None of these are nearly as bad as potato blight, which tomatoes also get. It is a disease of the leaves and stems so if you can cut the potato foliage down to below ground level before it comes, you have some chance of saving the potatoes. You cannot save the tomatoes – so the moral is try not to grow them near each other and do not put anything with blight onto your compost heap.

Other wildlife which you might encounter in your soil are centipedes, leatherjackets, ants and woodlice. Centipedes are a good thing to have because they don’t eat plants, but do eat other insects and bugs. Leatherjackets are the larvae of flying craneflies. They do eat plant roots and seeds, but are more of a nuisance in lawns. Ants can be a nuisance by moving soil and sand around, but you probably only want to deal with them when they get into the house. 

Most of my life I have wondered about woodlice, knowing that they must be a throwback from ancient times. They do not eat living plants, but do eat dead wood, dead plants and fungi. One of the funniest evenings I spent was betting on woodlice racing. The idea was that the winner was the one whose woodlice fell off the table first. If you have woodlice muthat roll up like a ball (and they seem rare these days), they can sit there for a good long time until someone shakes them off the table top.

Aphids in colour

The different coloured aphids affect different types of plants. The easiest ones to spot are the black ones. When I was young and foolish, I tried spraying against them. I soon learnt that spraying actually doesn’t work and often makes the problem worse. The secret is to cut or break the tops off the broad bean plants when you first see the blackfly. You can even do it before you see any blackfly which will make the plants more vigorous and give you more beans.

Whitefly are the ones that you often find in a greenhouse. These are sap-sucking insects which leave a sticky film over things. They prefer a dry atmosphere so spraying with soap and water or washing up liquid can help to control them. Washing the leaves of the plant will also help. Most greenhouses are cleared out at least once a year and they do not survive this.

Greenfly are the ones on your rosebuds and you can easily rub them off with your fingers early in the year. Greenfly can be particularly troublesome in dry years, But spraying them with a solution of washing-up liquid helps or merely washing them off is good. You don’t need to spend a fortune on ‘bug sprays’.

Grey aphids are often found on brassicas and sometimes survive the winter. They are difficult to spot and, for this reason, you might find yourself eating them by mistake. I always hope that the frost in winter is severe enough to kill them, but recently we have had some quite mild winters with very little snow. After the fairly wet winter that we have just had, it surprises me to find them on my purple sprouting broccoli. 

This is just a brief spin through various garden pests, but I have a chart which shows me that I have missed out beetles – such as asparagus and lily beetles – which you pick off when you see them. Lily beetles are bright red and are busy in the month of May. Another omission is carrot and onion flies. You can deter carrot flies with fine netting, or planting your carrots late in the season, or planting them in a raised bed half a metre above the ground, as these flies fly low near the soil. I do not find that onion flies are much of a problem, but they do affect my leeks.