Garden pests bear some definition. There are the tiny aphids – greenfly, whitefly, red spider mite, for example; larger beasts such as vine weevil (commonly found in pots), slugs and snails, squirrels, foxes, deer. Then there are those animals who may or may not be pests, for example, pets – dogs and cats in particular, yours or a neighbours; and chickens are becoming a frequent garden inhabitant. Oh and possibly children, teenagers and helpful spouses, but that’s definitely another story.
Some of these are easier to go to war with than others; for some you will have more armaments than the opposition. As there are so many and you don’t have all day to sit and read, in this blog I’ll concentrate on some of the smaller pests & their predators.
Firstly, a few simple measures which apply to all the plants: good hygiene and cultural practice: what this means is, for example, quarantine new arrivals and remove decaying material from around existing plants. Plant the right plant in the right place; give it good, nutrient rich soil; water when it’s needed; and light and air to suit. A healthy plant is more able to fight off infestations.
Aphids and spider mites are found on houseplants, in the greenhouse and in the garden. The controlled environment of houses and greenhouses enables the pests to be dealt with more easily. Some of the little pests may be noticeable and easy to pick off and squish. For others you may need reinforcements. Biological control is becoming easier for domestic gardener to access many are available online and through garden centres. Encarsa Formosa, a parasitic wasp that attacks aphids is particularly effective in a confined environment such as a greenhouse.
One thing to remember about using predators is that they will not totally eradicate your pests. Why? Because the pests are their breakfast, lunch and dinner. Whilst dedicated annihilators may be able to rid their garden of all pests from greenfly to deer in their dreams, the reality is that even using all the chemicals available, they’ll still be an aphid or slug sneaking in as soon as your back is turned.
Ah, slugs, the bane of many a gardener and probably, along with their cousin the snail, worthy of a blog to themselves. The tricks for dealing with these gastropods are many: a biological control which is proving useful is the nematode. Nematodes are tiny organisms, so small they are invisible to the eye, and are literally watered into the soil. Hence they are particularly effective for containers – your Hostas now have a chance! Home-made resources include hand collection and disposal; throwing over the fence is not recommended: they always return. Coffee grounds, egg shells and hair clippings all work on the premise that they dry out the slug or snail thereby preventing them from reaching your precious plants.
Predators: some of these may also come under the category of beneficial insects.
This makes most people immediately think of bees; who don’t eat pests, it’s true. But other beneficial insects, such as ladybirds and lacewings, do eat pests. Encouraging them into your garden to do battle for you by growing a wide range of flowering plants and providing over wintering shelter is a win-win situation. Native species are good to include in your garden for this and other reasons, not least for ornamental pleasure; Yarrow and Tansy for example. And if I may refer back to my comment “A weed is a plant in the wrong place”, dandelions are an excellent food source for ladybirds and lacewings! Some of these beneficial insects who are predators can be as mean as any hunter twenty times their size. Ladybirds positively chomp on aphids with their strong mandibles.
Other helpful predators against the smaller pests are amphibians such as frogs and toads, who will enjoy keeping your slug population under control. A small pond and somewhere cool and shady to sit and wait for prey should keep them happy.
Hedgehogs and birds play a part too: that cheerfully serenading blackbird will smash snail shells and eat the contents. However, if it’s the birds that are the pest, get in touch, I have a friend who can help you in an environmentally friendly way (he uses hawks).
Lastly, let’s not forget the plants themselves: companion planting can help in the pest reduction. Mint, for example, has been known to reduce carrot fly and flea beetle infestations; being strong smelling it confuses them. Being invasive itself, mint does need controlling…I smell a blog is needed on companion planting too.