I’ve called this month’s column ‘popular pests’ – not because you want to invite them to your garden party, but because this is the time of year they make themselves busy. And the two top of the pops are aphids and our old friends the slugs.
So before we look at each one, I first want to share with you the organic approach to dealing with pests. As you’ve probably guessed, it doesn’t involve reaching for the bright red bottle of toxic bug spray.
Instead, the canny organic grower will work on the principle of prevention. Here’s how:
- Keeping your soil healthy and full of life. If your plants are well nourished, it helps them withstand the onslaught of most pests. So put plenty of home-made compost into the soil to feed the important soil micro-organisms, and it’ll add slow release nutrients to boost your plants.
- Encourage those helpful pest predators. Watching nature work in your growing area is fascinating. Aphids and caterpillars will hatch in perfect time for birds and insect larvae who feed on them. You can work with nature by creating a diversity of plant life which in turn will attract a huge mix of beneficial wildlife. Plant flowers with your veg to bring in a variety of aphid munching insects; put in shrubs for birds to shelter in; and leave grass long to provide insect and small mammal habitat.
- Choose plants and varieties that are suited to the site and soil. Plants which struggle to grow will be weak and vulnerable to pest and disease. Similarly, if you have seedlings, give them a chance to mature before planting them out. They will have less soft green growth which is so attractive for pests to eat.
- Use traps, barriers and covers to keep those hungry slugs, caterpillars and pigeons at bay. And be vigilant! Keep checking your defences. Especially after rain or in damp conditions, when dry slug deterrent material will have become moist.
Now, here’s is a quick check list on how to deal with your dastardly duo, and for more, go to Garden Organic.
Often known as greenfly or blackfly, they cluster around tender young growth, sucking out the sap and causing young shoots to become weak and distorted. A simple way to prevent them is to avoid using too much nitrogen-rich fertiliser which encourages soft leafy growth.
Then you have a number of options to keep on top of them. Encourage creatures that eat aphids (such as birds, earwigs and bats) by providing them with habitat and food. Grow flowers like fennel, cow parsley and the daisy family which attract hoverflies, lacewings and ladybirds – these insects and their larvae feed on aphids. Finally, you can squash any you see (wear gloves if you’re squeamish) or use a strong jet of water to dislodge them.
It’s important not to panic when you see aphids. You need to be patient and wait for the predator. After all, if we wipe out the aphid population, we also threaten the ladybirds’ and songbirds’ survival.
Slugs love rich, damp conditions – which means organic growers can suffer particularly unfairly as they provide compost mulches which are slug heaven.
Tempted by slug pellets? Think again First of all, never buy ones with the deadly poison metaldehyde in them. The pellets certified for organic use ferric phosphate which degrades harmlessly into the soil – however, other chemical ingredients in the pellet may cause problems to soil life. So use them very sparingly.
Whatever your way of dealing with pests, don’t ever be tempted by the toxic poisons which are so freely available on garden centre shelves. They kill not only the pest but other species as well. If you spray an aphid, the chances are you will kill a friendly hoverfly; if you poison a slug you might poison the toad who eats that very slug. Just let nature deal with your popular pests.
The Grow Your Own Wicked Leeks series is written by Garden Organic, the national charity for organic growing. Each month we bring you timely advice on what to do in your organic patch, whether you’re an experienced grower or just starting out. Share your own tips and gardening photos on social media under #GYOWickedLeeks.