Dealing with Common Allotment Pests Naturally

Work With the Plot, Not Against It

Every allotment has its resident troublemakers, and every grower has, at some point, stood over a row of shredded cabbages and muttered dark threats. The temptation is to reach for a bottle or a box of powder and be done with it. But on a smallholding or allotment, where you are often growing food for your own table and sharing the ground with children, pets and wildlife, the gentler approach is usually the smarter one. It also tends to work better in the long run, because chemicals knock back the predators along with the pests and leave you with a bigger problem the following season.

What follows is not a list of miracles. It is a set of habits — barriers, timing, companion planting and a bit of encouragement for the creatures that do the job for you — which, stacked together, keep losses to a level you can live with.

Slugs and Snails: Barriers Beat Baits

Slugs do most of their damage overnight, so the first useful thing you can do is go out with a torch after dark. Ten minutes with a bucket of salty water will tell you exactly which parts of the plot are worst affected, and hand-picking genuinely makes a dent in the population.

For protection, barriers are more reliable than anything you scatter on the soil:

• Copper tape around raised beds and pots gives a mild electric tingle that slugs dislike. It works best on clean, dry surfaces and needs replacing as it tarnishes.
• Wool pellets swelled with water form a rough, irritating mat around plants, and they double as a slow-release feed as they break down.
• Sharp grit, crushed eggshell or ash rings around delicate seedlings help, though they need topping up after rain.
• Beer traps sunk to soil level still catch plenty, as does a half-grapefruit shell placed upside down as a daytime shelter you can empty each morning.

The single most effective tactic, though, is to raise your plants out of reach. Sow brassicas, lettuce and courgettes in modules and grow them on until they are sturdy, then plant out. A big, tough plant shrugs off a nibble that would finish off a tender seedling. If you do want a bait, ferric phosphate pellets are approved for organic use and are far kinder to hedgehogs and birds than the old metaldehyde ones — but use them sparingly.

Pigeons, Crows and the Brassica Problem

Wood pigeons can strip a row of young kale in an afternoon, and they learn your routine quickly. Netting is the answer, but it has to be done properly or it causes more trouble than it solves.

• Build a frame first. Hoops of blue water pipe or a simple timber cage keep the net off the leaves. Netting laid directly on plants lets pigeons peck straight through it and gives cabbage white butterflies a place to lay.
• Use the right mesh. A 20mm mesh stops butterflies and most birds. Wider "bird netting" lets small birds in, which is not always a bad thing — they eat aphids — but it will not save your greens.
• Pin it down. Peg the edges or weigh them with bricks. A gap at ground level is an open invitation.
• Fit brassica collars around the stem at planting time to block cabbage root fly, which causes plants to wilt and collapse.

Bright, flapping deterrents — old CDs, silver tape, scarers — work for a week or two and then the birds ignore them. If you have a lot of ground, invest in a proper walk-in cage for your brassicas and save yourself the daily worry.

Aphids: Bring In the Cavalry

Aphids multiply with alarming speed, but they are also the easiest pest to hand over to somebody else. Ladybirds, lacewings, hoverflies and tiny parasitic wasps all feed on them, and your job is simply to make the plot welcoming.

Companion planting does real work here. French marigolds and nasturtiums draw aphids away from your beans and brassicas, acting as a sacrificial trap crop you can pull up and bin once it is crawling. Poached egg plant, phacelia and calendula are magnets for hoverflies, whose larvae hoover up aphids by the hundred. Strongly scented neighbours — chives, garlic, mint, coriander — seem to confuse the winged aphids looking for a landing site.

For a direct hit, a firm jet of water from the hose dislodges colonies on roses and fruit bushes. On sturdy plants, squash them with thumb and forefinger — inelegant, but effective. A dilute soap spray works on soft-bodied aphids, but apply it in the evening when bees are away and rinse edible leaves before use.

Look After the Predators

Half the battle is simply not evicting your allies. A plot with a bit of untidiness at the edges will support far more pest-eaters than one scraped bare.

• Leave a log pile or stone heap in a corner for hedgehogs, slow worms, frogs and ground beetles. Frogs are voracious slug hunters and worth their weight in lettuce.
• Plant a small flowering hedge or a few native shrubs for nesting birds. Blue tits will clear caterpillars from your fruit trees in spring.
• Keep a bucket pond, even a small one, safely fenced if children are about. Frogs and newts will move in within a season.
• Let some herbs flower. Bolted parsley, dill and fennel feed hoverflies long after the vegetables have finished.
• Avoid the urge to tidy everything in autumn. Seed heads and hollow stems shelter overwintering beneficial insects.

Stay Ahead Through the Season

Most pest trouble is really a timing problem. Sow a little more than you need, keep a few spare plants in pots as replacements, and check the plot two or three times a week rather than once a fortnight. Squash the first aphids you see, lift the first slug you find, and pin the netting down before the butterflies arrive rather than after.

Keep a rough notebook of what was eaten and when. After a couple of years you will know your plot's particular villains, and you can plan around them — a trap crop here, a net there, a wild corner left alone — instead of fighting the same battle every June. Simple country living rarely means a perfectly pristine plot, and that is fine. A few nibbled leaves and a garden full of birdsong is a fair trade.