Controlling pest and disease organically
‘How do you stop slugs?’ Is undoubtedly the most frequently asked question.
It is true of course, that slugs and snails are one of the most destructive pests, but there is a seemingly endless list of pests and diseases that can thwart your quest for produce perfection. Here is a small selection of the most common pests and diseases, and my preventions.
Aphids - Avoid using nitrogen-rich fertilizer, as it can encourage soft fleshy growth which is susceptible to pest attack. Try to encourage natural predators by growing plants that will attract them, leaving a wilder area of your garden can even encourage ladybirds and lacewings. Inspect plants regularly, rub off infestations and wash plants in a soft soap and water solution. A strong jet of water can also dislodge them.
Blight - Look out for brown spots appearing at the base of potatoes and tomatoes in mid- summer. Blight usually occurs in damp, warm weather so good ventilation and ample spacing can help. Avoid growing tomatoes and potatoes in close proximity because it can easily jump from one to another and be sure to burn infected material. Sometimes potato tubers can be saved if you remove infected foliage immediately, and removing the lower leaves of tomato plants can prevent spread.
Caterpillars - Removing egg clusters from the underside of leaves before they hatch is the most efficient way of preventing infestation. Companion planting with Nasturtium and Calendula can lure the butterflies away from your crops. Fleecing and netting can prevent butterflies from landing, just be aware that this can create more work.
Clubroot - Affecting the cabbage family, clubroot wilts leaves and distorts root growth. Prevent it from entering your garden by using sterile compost and clean trays and pots. Burn infested plants and crop rotate.
Mammals – Rabbits are one of the most devastating of all garden pests, particularly affecting rural areas. Rabbit fencing is essential to prevent clear felling of your young seedlings, dig fencing down at least 12 inches to prevent burrowing or simply lay the netting on the ground and pin it down. The netting should be at least three feet above the soil surface. Gun control can be affective and end in delicious results.
Nutrient deficiency – Magnesium and calcium deficiency are the most common, usually seen as yellowing leaves and stunted growth. Adding a variety of composted plant material to your heap will enable a wider variety of nutrients to be put back into the soil. Using seaweed and comfrey feed can add essential trace elements.
Slugs and snails – Healthy plants are more likely to recover from pest damage, so be aware of the health of your plants and always protect the most vulnerable. Keeping the garden tidy can dramatically reduce habitat for slugs and snails. It’s advisable to pick up piles of weeds and keep edges tidy. In my experience, physical barriers usually aren’t that effective but beer traps can work. When you dig over a bed make sure you knock out the clods and rake over to prevent slugs from crawling in and laying eggs. If all else fails you can use organically approved slug pellets sparingly.
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Cabbage and chicory grown by Will and the Land Team at River Cottage HQ.