Early summer is the time for maximum growth in the garden. The new stems and leaves on our plants, plumped out by rain, fertilisers and human kindness are luscious – and irresistibly delicious to some of our garden visitors. Pesky sap suckers seem to have expensive tastes and well bred, cultivated plants are just so much tastier than tough old weeds. It can seem like the garden is under siege, especially when we come out in the morning (evil deeds mainly happen at night) and discover the carnage. It is very tempting to reach for a bug spray and nuke the lot of them.
But, before we do that, it is worth remembering that most pesticide sprays are non-specific and will kill a wide variety of insects; the good, bad, the bug-ugly – and the butterflies. Luckily we are becoming more aware of the effects of chemical sprays and the days of DDT (the poisonous compound that accumulates in the fatty tissues of animals – including humans) but it has taken a long time. Rachel Carson’s classic book on the subject, Silent Spring, was first published way back in 1962.
Alternative routes to sprays require a more benign approach to pest control through healthy practices. The aim is to maintain a more natural balance and prevent the build up of pests in the first place, but the problem is that – oddly – our gardens are not always the most natural of environments in the first place. Plants we consider ‘standard’ are mostly pampered non-natives and the edible crops are grown in neat, easy to feed on rows. It can be done though. We just need a range of strategies and, as in many hostile situations, an insight into the lifestyle choices and habits of our enemies.
A healthy balance
A natural ecosystem is a carefully balanced web of life; each organism within it has a role that has evolved over millions of years. In the garden it is us who organise the ecosystem, by going to the garden centre and popping in a random selection of things that take our fancy – plants that fill a gap in our borders rather than a specific ecological niche. Growing the right plant in the right place will help. Plonking a delicate woodlander into a scorching sunny border, or miring a Mediterranean meadow plant in heavy clay means that they use up all their resources just trying to survive. Unhappy plants, much like unhappy humans, are more prone to pests and disease.
Spring is the best time to give your plants food – but only if they need it. Too much nitrogen will lead to excessively lush leaf growth. Soft, sappy leaves are easier to bite into. Don’t feed plants much past the summer or you will encourage late growth that will be prone to winter frost damage, leaving them open to pest attack. Warmer winters enable more pests to survive in situations where they might once have perished, and new ones are regularly creeping in on foreign grown plants, from where they can spread very rapidly.
Catch them early
Get out in the garden early in the season and keep an eye out for the first of the pests to arrive and you may be able to catch an infestation before it starts. Think of it as the gardener’s equivalent of a ‘stitch in time’: a bug squished in the hand is better than thousands on your plants. And catching them early in their life cycle, before they hatch and fly off to reproduce, will help too.
Encourage beneficial predators
Set up bee/ladybird/lacewing homes and hedgehog houses. Bees are essential pollinators and the others are all voracious eaters of aphids, whiteflies, mealybugs and many other insect pests. Make log piles for beneficial bugs and beetles to overwinter in. Plant a nectar border to encourage bees, hoverflies and other pollinating insects and grow plants for their seed heads to attract the birds. All birds feed insect to their young in spring and although birds will also eat your seeds, their bug catching role in spring is very useful. Even wasps do a good job, hunting down caterpillars and grubs and clearing up debris and rotting fruit.
Putting this in place at vulnerable stages will deter many bugs, depending on the gauge of net. Fine netting will prevent flea beetle and small flies (whitefly and carrot fly), the next size up will protect crops from Cabbage White butterflies and bird netting will deter pesky pigeons – make sure it’s pegged down well so that wildlife can’t get tangled in it.
This is an attractive way to deter pests and works by confusing the insect (they’re easily confused) by disguising the smell of the crop. The most well known of these is planting carrots among onions, which helps to deter carrot fly. French marigolds attract hoverflies, and deter aphids and whitefly.
Rabbits and deer can be a big problem, as they will decimate plants within a short space of time. Fencing is the best option. It needs to be dug into the ground at an angle to prevent burrowing, and if deer are the problem, high enough to stop a deer jumping over. There are lists of ‘rabbit proof’ plants available (look online), but the rabbits haven’t always read these lists. In general it’s the tasty new growth and young plants that they’re attracted to.
Slugs and snails
In wet years the ‘most hated pest’ award invariably goes to these slimy creepers, but there are other contenders that come and go, depending on how cold the winter is. There are endless gruesome solutions for controlling slugs and snails, but understanding a little about when they’re likely to be at their most active will help.
They first appear at the beginning of the season when all the fresh, succulent new growth emerges and the conditions are damp. As the weather warms up you’ll find them in the cool of the early morning and at dusk and on rainy days.
They don’t like travelling over gritty, spiky, oily or dry surfaces and copper will give them an electric shock, so there are lots of barrier methods, and they are drawn to the smell of fermenting fruit which is why the ‘slug pubs’ work so well.
This is a serious pest in containers and evergreen shrubs are especially prone. The adults make notches in leaves, but the larvae do the most damage by eating the roots. You may not know they’re there – until the plant suddenly dies. Check containers on purchase. A biological control is available, but only use in the warmer months, as it is temperature sensitive.
Greenfly and blackfly are sap suckers (too kind a name for them) that start building up in numbers when the weather warms up in late spring. They can quickly cause large infestations because they’re born pregnant, so don’t even have to pause to find a mate. They just keep eating and popping out babies as they go… A jet of water will wash them off, or if you’re not squeamish (and gardeners soon learn not to be), just rub them off with your fingers. Aphids also make tasty snacks for baby blue tits.
Look out for these smart little beetles, with their orange backs and black undersides. The larvae have a nasty habit of hiding in their own excreta, the grown-ups have developed an annoying survival technique: dropping to the ground upside-down, their black undersides hard to spot in the soil. Outwit them by holding one hand under the leaf they’re on and then, if you don’t catch them, they’ll drop into your palm. Not so pretty now are we?
Organic pesticide recipe
Combine 100g chilli peppers with 100g garlic cloves and/or onions.
Blend the vegetables together in an electric blender. to make a thick, chunky paste.
Add the vegetable paste to 500 ml of warm water and mix thoroughly.
Pour the solution into a plastic or glass container and allow it to sit for 24 hours. If possible, keep the mixture in a warm spot.
Pour the solution through a strainer, removing the vegetables and collecting the vegetable-infused water into another container. This water is your pesticide. Do not mistake it for salad dressing.
For details of Jo Arnell’s courses and workshops look at hornbrookmanor.co.uk or call 01233 861149
Caterpillar eggs clinging to a leaf and ready to hatch into action
Ladybirds will help you combat the bad bugs
Nasturtiums in their caterpillar-free glory
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