Organic pest and disease control

If you're new to organic gardening you may think it means extra work but it simply requires more thought. Check out our basic organic methods to controlling pests and diseases.

Organic pest and disease control

How to get rid of slugs

  • Barriers of anything sharp and gritty will protect your tender plants.
  • Bran and salt will dehydrate slugs and kill them.
  • Make a ‘slug pub’ by filling a saucer with beer – slugs will drink it and die from dehydration.
  • Buy a band of copper from a garden centre which give slugs an electric shock.

Healthy soil
Healthy growth depends on healthy soil. Too much fertiliser and your plants will be soft and sappy - resulting in a lovely lunch for garden pests. Feed your soil with a diet of garden compost and leafmould rather than the fast-food artificial fertilisers that are designed to feed only the plant. Research has proved feeding the soil rather than the plant means stronger growth and better resistance to pests and diseases. Another very important tool in preventing pests and diseases is choosing varieties of plants that have been bred for their pest and disease resistance.

Crop rotation
If you have a vegetable garden, you must practise crop rotation as a way of controlling pests and diseases. This involves dividing your vegetables into at least four groups that stay together each year but move onto the next part of the rotation every spring. The vegetables are grouped by family as well as similar feeding habits. Apart from being the best way to build soil fertility, it is the most important factor in controlling the build up of pests and diseases.

Barriers are the best way of reducing pest damage. Follow these tips to to keep the pests at bay:

  • You can stop vegetables being attacked by flying pests by covering them with a fine mesh.
  • Cabbage collars and bottle cloches - clear plastic drinks bottle with the top and bottom removed - are great at preventing pests like slugs and root flies from attacking vegetables.
  • Small gage chickenwire will stop mice and cats from getting at your vegetables. Wrap it around your flowering bulbs to prevent squirrels from digging them up.
  • Netting can also be very useful at preventing bird damage to fruit and vegetables.
  • Barriers can also be used to prevent diseases. For example, peach leaf curl is a devastating fungus that can simply be prevented by placing a barrier of polythene sheeting over a trained peach tree in the winter.

    Another popular method of protecting your plants is to use traps. This can be anything from beer traps for slugs to codling moth traps hung from your apple trees. Sticky traps are very popular with the organic gardener. Greasebands, painted around the trunks of apple trees in autumn are a popular way of preventing the wingless female winter moth from climbing up the tree to mate. Sticky glue is also very useful for glasshouse staging if you have a problem with ants. Sticky yellow bits of card hung up in the glasshouse can help reduce the population of whitefly.

    Beneficial insects
    Many insects and wildlife can be beneficial to your garden and these really are your best friends when it comes to controlling pests. 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 such as 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.

    When trying to control pests and diseases in an organic garden, always remember to be as hygienic as you can. So, if you're trying to remove a diseased branch from a tree, cut into healthy wood and always wash your tools in boiling water afterwards. Always scrub out your pots and give your greenhouse a good scrub every winter to get rid of those over-wintering pests. Maximising air circulation by correct pruning and leaving just a little more space between your plants can help control fungal diseases, for example powdery mildew in roses.

    Always check your plants for pests
    Finally, and most importantly, be vigilant and check your plants regularly so that any pest and diseases don't get a chance to get a hold. For example, if you start checking the centre of your gooseberry bushes in April for sawfly eggs and larvae you can remove them and therefore prevent them from defoliating your crop. Also be wary of accepting onion and cabbage plants as they may well carry the dreadful diseases of onion white rot and clubroot which you will never be able to get rid of. If you have an allotment with these diseases don't use the same tools or boots in your own garden because you will spread them easily and quickly.

    By following the simple tips above, you can become an organic gardener with planning, forethought, observation and vigilance. When it comes to controlling pests and diseases in an organic garden, always remember prevention is better than cure. Get more tips on how to become a green, organic gardener on our website.