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.