We all prefer to stay chemical free in the garden if we can, and we also want to live and let live, but sometimes we have to take matters into our own hands, when the garden is subject to unacceptable levels of pest damage. Then we turn to Wildlife-friendly pest control to avoid harming the environment and minimise collateral damage on the animal kingdom.
In part 2 next month I will discuss some of the useful methods of pest control that minimise impact on the environment. This month we will talk about more general measures for pest and disease management. One key rule to remember - when it comes to pests, prevention is better than cure.
There are a number of general measures you can take to reduce the likelihood and impact of pests doing serious damage. However small your garden or vegetable plot, it should have a self-regulating ecosystem in place to control pests and keep your plants healthy. The simplest way to create this ecosystem is to plant a range of plants which attract natural predators that feed on pests. Ideally, these plants should provide food (in the form of nectar, fruit and pollen) and shelter for predators and sacrificial crops to maintain pest colonies.
A surprisingly useful crop is a clump of nettles. This will harbour aphids which feed predators such as ladybirds and lacewings. If any aphids then attack your crops, the predators will be on standby to clear them up.
Beneficial insects and wildlife are our best friends when it comes to controlling pests in your garden and vegetable patch. Planting simple annuals amongst your vegetables, such as Californian poppies and marigolds will attract a wealth of beneficial insects like ladybirds and hoverflies who will gobble up your aphids. Plant a few native shrubs and herbaceous perennials (i.e. hazel and hardy geraniums) in your garden; create a pond; leave a small pile of logs in the corner of your garden and feed the birds throughout the winter. Doing any or all of these will keep enough wildlife in your garden to eat thousands of pests and their eggs. Hoverflies are a very useful predator of aphids – many of our hoverflies however have short tongues, so they like open flowers like Tansy or Poached Egg Plant.
The key tip for organic (or verging on the organic) gardeners is feed the soil, not your plants. Healthy plant growth depends on a good soil. Too much fertiliser and your plants will be soft and sappy. The result will be a lovely lunch for the pests and the need to spray. Feed your soil with a diet of garden compost (available from the allotments on Saturdays 10-12) and leaf-mould, in preference to using “fast-food” artificial fertilisers designed to feed only the plant. Feeding the soil rather than the plant will mean stronger growth and better resistance to pests and diseases. Research has proved this to be true. Looking after the soil is the cornerstone of organic gardening.
There is no substitute for visiting visit regularly and checking plants frequently for a build up of pests – this is the best way to avoid any nasty surprises. If you see a weak or sick plant - remove it. It is tempting to leave them, on the off chance they will recover, but this will encourage pests, and once they have finished with the weak plants they move onto the healthy ones!
Try to select plants that are resistant to pests and disease. There are so many varieties available now, and whatever your particular pest or disease, there is almost certainly a variety bred to resist it. Crop rotation also plays a part here - dividing your vegetables into at least four groups that stay together each year but are rotated to a new part of the plot every spring. This is also a great way to improve the health of your soil. Most committed organic growers practice crop rotation.
Remember, when trying to control pests and diseases in an organic garden, hygiene is an important factor. Always scrub out your pots and give your greenhouse a good clean every winter to get rid of those over-wintering pests. Air circulation around plants is vital to deter many diseases – so maximize this by correct pruning, and leaving just a little more space between your plants can help limit the spread of fungal diseases.
Well there is an obvious answer – we all do! There are some insects that I sometimes think we could do without (wasps for instance?) – but they all play a part in the complicated food-chain that is nature. Seeing any insects in the garden is a good thing in general, as where you see one, others will lurk! If we do end up with too many of one type tend then nature has a way of re-balancing things pretty quickly.
There are certain insects (plus the humble worm) that we gardeners cannot do without. Wasps may have a use after all, in that they are voracious killers of caterpillars, aphids and other invertebrates. Ladybirds, hoverflies and lacewings all put aphids high on their menu. Ground beetles eat slugs and snails (hooray for them!).
Bees have been in the news of course, as their numbers have plummeted worldwide. Much of this has been laid at the door of a virus spread by the Varroa mite. Whilst this has undoubtedly been a major factor, there is no doubt that a lack of food, plus the longer term effect of pesticides, have eroded bees resistance to this, and other viruses. The major issue, and one we can do something about, is the impact of pesticides. Please don’t use chemicals that contain “Neonicotinoids” – avoid pesticides altogether if you can.
What else can we do to help them? Bees, and other pollinators, need 3 key things – food, water and shelter. Water is easily provided - if you have a pond or bird-bath then you have already ticked that particular box!
For shelter - log piles are attractive to all sorts of wildlife. Drill holes of varying diameter (2-8mm) in the ends and this will attract bees – especially if sited in the sun. A log-pile in the shade will remain cool and moist – good for beetles and amphibians. To create the best habitat for the widest variety of wildlife, use logs from local, native trees, but if you can’t get hold of any, use whatever you can find — even sticks or bought logs destined for a wood-burning stove. Partially bury the bottom layer and fill a few gaps with fallen leaves, moss and soil.
Leave untidy bits of the garden – especially in the winter, where dying plants and rough grass provide excellent shelter. Your own compost heap is both a preferred source of plant nutrients than peat, and a brilliant shelter for wildlife. Climbing plants are a great source of shelter, where insects can hide from their enemies amongst dense foliage.
Food sources for wildlife should be varied and provided over as long a growing season as possible. Early flowering plants are of particular importance to wildlife coming out of hibernation.
Grow nettles! Even a small patch of nettles will attract the nettle aphid which will, in turn, attract aphid-eating ladybirds to your patch. The nettle aphid only visits nettles, but because it emerges earlier than other aphids, it brings ladybirds to your veggie patch long before other aphids have had the chance to build up their populations on your roses and broad beans, so they’re on hand to tackle early infestations. The stinging nettle is one of the UK’s most important native plants for wildlife. It supports more than 40 species of insect including some of our most colourful butterflies. Nettles can also be a useful part of our diet - used as a blood purifier, and high in iron and potassium.
There are a number of flowers and herbs that will serve well to attract all types of insect. I have identified some of the most beneficial (i.e. attract ladybirds, lacewings, hoverflies, ground beetles) below (all are pretty easy to come by and to grow):
Cornflowers - has extrafloral nectaries, which means the plant's leaves release nectar even when the flowers are not blooming. Research in Germany has found that cornflower nectar has a very high sugar content of 75 percent. This nectar is highly attractive to many insect species.
Borage – an annual herb with bright blue clusters of edible, cucumber-flavored flowers. Studies in Switzerland have shown borage to be exceptionally attractive to good bugs, with an average of over 100 beneficial insects found in just 1 square yard of borage. In addition, common green lacewings have a very strong preference for laying their eggs on borage.
Anise Hyssop (aka Korean mint) - perennial, summer-blooming with fuzzy purple or violet flower spikes on 2 to 3 foot high plants with licorice-scented leaves. The nectar-rich flowers are very attractive to both butterflies and pest-eating beneficial insects. It self-seeds and spreads quickly making it an ideal choice for filling in sparse areas of your garden. At the same time the seedlings are easy to pull so it is simple to weed out any extras that have grown where you don't want them. In fact, weeding them out is actually quite a pleasure thanks to the pleasant aroma.
Fennel - Long-lasting fennel flowers are extremely attractive to all nectar-feeding beneficial insects, and the feathery green or purple foliage looks wonderful in spring and early summer.
Foxglove – bumblebees love them!
Thyme - This herb provides excellent ground cover in gravel gardens, creating safe spaces for beetles and other invertebrates. Its nectar is also a favourite of bees.
Lavender - The calming scent of lavender on a sunny patio is a magnet for bees and butterflies. When the purple blooms go to seed, birds can tuck in.
Honeysuckle - This climber buzzes with visitors in the summer months, attracting nectar-loving insects including the hummingbird hawk moth. Warblers and thrushes enjoy the berries.
A strip of flowering plants — particularly umbellifers such as fennel, angelica, dill and coriander — will attract hoverflies and lacewings, whose larvae feast on aphids. Angelica is also thought to attract common wasps, which will destroy anything from aphids to caterpillars and other flying pests.