Natural Remedies for Common Garden Pests

There is a point in every growing year when the plot looks triumphant and then, quite suddenly, something has been at it. Holes appear in the brassicas, seedlings vanish overnight and the broad beans are wearing a grey fur of aphids. Take heart. On a smallholding or a country garden you have one enormous advantage over any commercial grower: you can afford to be patient, you can work by hand, and you can let the wildlife do a good deal of the labour for you.

Work With the Predators You Already Have

Before you reach for anything, count the allies already on your patch. A single ladybird larva — a spiky little crocodile of a thing that most people mistake for a pest — will eat dozens of aphids a day. Lacewing larvae, hoverfly grubs, ground beetles, centipedes, spiders, frogs, toads, slow worms and every wren and blue tit in the hedge are all working the same shift. Your job is simply to make them welcome.

• Leave one corner rough: a log pile, a leaf mound, a patch of long grass. Ground beetles and slow worms need somewhere damp and undisturbed to shelter.
• Let a few herbs and umbellifers flower. Fennel, dill, coriander and parsley left to bolt are magnets for hoverflies, whose larvae are superb aphid hunters.
• Put in a small pond, even a sunken washing-up bowl. Frogs and newts will arrive and they eat slugs far more efficiently than you ever will.
• Stop using broad-spectrum sprays, including organic ones. They do not discriminate and they wipe out the predators along with the problem.

Hedges matter too. A mixed native hedge, or even a few established shrubs, gives birds nesting cover, and a pair of blue tits feeding chicks will clear a surprising amount of caterpillar damage in a fortnight.

Barriers Beat Battles Every Time

Netting is unglamorous but it is the most reliable tool in the box. Cabbage white butterflies are the chief enemy of anything in the brassica family, and a fine mesh cover over your cabbages, kale and sprouts stops them laying in the first place. Use hoops to keep the net clear of the leaves, and peg the edges down firmly — butterflies will happily squeeze through a gap the size of a thumb.

Carrot fly is a low-flying insect, so a barrier of fine mesh or fleece at least 60cm high around a carrot bed genuinely works. Do the same for onions and leeks against onion fly. For fruit, bird netting over cherries and soft fruit saves the crop, but check it daily during the season and never leave gaps at ground level where a blackbird can become trapped.

For slugs in pots and raised beds, copper tape and wool pellets are worth the money. Grit, eggshells and sand are not, once they get wet.

Plant the Strong Smellers

Pest insects hunt largely by scent, and a fog of aromatic herbs does confuse them. Underplant brassicas with chives, garlic chives, sage or rosemary. Thread a row of onions or leeks through your carrots. Tuck French marigolds among tomatoes and nasturtiums along the edge of the bean bed as a sacrifice crop — blackfly will land on the nasturtiums and leave your beans mostly alone.

A simple garlic and chilli spray is useful for a bad aphid outbreak: steep a bulb of crushed garlic and a couple of chopped chillies in a litre of water overnight, strain, add a drop or two of washing-up liquid, and spray. Test it on one leaf first, and never spray in full sun or on a plant in flower.

The Dusk Patrol

Slugs and snails do most of their damage between dusk and dawn, especially after rain. Go out at about ten o'clock with a torch and a bucket and you will catch the culprits red-handed. Drop them into salty water, or keep a few ducks — Indian runners will clear a kitchen garden of slugs with real enthusiasm.

Two practical habits help enormously. Water in the morning rather than the evening, so the soil surface dries before the night shift emerges. And keep beer traps shallow and emptied every couple of days, remembering that they kill ground beetles too, so use them sparingly. Where slugs are truly overwhelming, nematodes watered onto damp soil in spring or early autumn are a targeted, biological option that leaves everything else alone.

Accepting Your Share of the Harvest

Here is the truth nobody tells new growers: a perfect plot is not the aim. A few holes in the chard, a nibbled outer leaf on a cabbage and a handful of aphids on the roses are entirely normal, and they cost you very little of the actual crop. What looks like ruin in June is often just a plant that has grown through it by August.

Set yourself a threshold. Handpick while numbers are small, net the crops that really suffer, and leave the rest. The aphids you tolerate this month are feeding the ladybirds that will patrol your beans next month. A garden with a little damage in it is a garden that is part of something bigger — and that is a good deal more rewarding than a plot kept under chemical lock and key.