We all want to control pests and weeds in our gardens but more and more of us want to do this organically. We love healthy good food free from chemicals and we worry about the plight of bees and other beneficial insects – so let’s use natural control methods. We are all part of a bigger picture, a food chain that was in place long before pesticides and herbicides were created.
The first line of natural pest defense is healthy soil. It provides young plants a healthy start and gives them strength to withstand some pests and diseases. Adding organic matter every year will encourage organisms (soil bacteria, fungi, nematodes, etc.) to break that matter down further, releasing nutrients that aid plant growth and defenses.
Encouraging wildlife to inhabit your garden is the next plan of action. You can use techniques to encourage the species that will benefit your plants but not destroy them. For example, birds are a beautiful addition to a garden. They will help reduce pests such as caterpillars, aphids and beetles, but they will also feed on your soft fruits like raspberries, blueberries, cherries, and more. To avoid having your fruit and veg munched, keep allotment planting and natural garden planting separate. Consider including a section in your garden with enough shelter and food source so birds won’t need to eat your prized fruit. If you don’t have the space for a separate area, or your crops are still being devoured, you can protect your soft fruit with cages or netting.
Hedgehogs are superb garden-friendly animals who will happily help you with slug management, avoiding the need for poisonous slug pellets, a particular concern for those of us who have children and or pets. Slugs will chomp through leafy crops and lush ornamental plants such as Hostas and Chrysanthemums. Hedgehogs numbers are declining severely in Britain but there are some simple ways to encourage them back into our gardens where they can thrive. Hedgehogs need more than one garden to survive. If you live in a residential street with adjoining gardens, talk with your neighbours about cutting or raising fences to create a 12cm (5in) hole for hedgehogs to crawl through. After creating this ‘wildlife corridor’, plant hedges and create areas of debris, provide feeding boxes with either cat or dog food, and a water supply. Finally, if your garden has a pond, add ramps or sloping banks to give hedgehogs an escape route so they can get out of the pond easily.
If hedgehogs are not a viable in your garden, then nematodes are an excellent biological control when it comes to controlling slug and snail populations. These micro-predators are invisible to the naked eye and can be purchased at many garden centres. Harmless to our pets, plants, and ourselves, they are easily applied and watered into the soil.
Aphids (greenfly and blackfly) can smoother roses, tomatoes, cabbages and many other plants. They suck plant juices out of the leaves, buds, stems, and roots of plants. This not only damages and weakens the plant, but can potentially introduce harmful viruses. To control these winged pests, you can physical squash them, wash them away using water, or introduce plants that encourage hoverflies and ladybirds, both of which feed on aphids. Plants that encourage hoverflies and ladybirds include Tagetes tenuifolia (Signet marigold), Potentilla crantzii (Alpine cinquefoil), Achillea filipendulina (Yarrow), Anethum graveolens (Dill), Angelica gigas (Korean angelica), Tanacetum vulgare (Tansy), Foeniculum vulgare (Fennel), Veronica spicata (Speedwell), Allium tanguticum (Lavender globe lily), Ajuga reptans (Bugleweed) and Rudbeckia fulgida (Black-eyed Susan). You can also buy live ladybirds to do the job but it is much better to entice them naturally.
For more information other troublesome pests and diseases such as Winter moth caterpillars, beetles, and red spider mite, visit our pest and disease page and build your own personal plant list to see what to look out for.