Grow cabbages, kale, broccoli or any brassica without protection and the cabbage white butterfly will find them — the caterpillars can turn a healthy bed into a lace doily in days. The direct answer: cover brassicas with butterfly netting the day you plant them out, keep the mesh off the leaves, and seal every edge — a 5–7 mm knitted mesh stops the butterfly from ever laying eggs, which means no caterpillars, no sprays and no re-sowing. This guide covers the mesh that works, the installation mistakes that let pests in anyway, and the weekly habit that makes the difference.
The butterfly itself is harmless — it feeds on nectar. The damage is her eggs: laid on the underside of brassica leaves, hatching into caterpillars that eat around the clock. A single plant can host dozens; a bed of seedlings can be stripped before you notice the first hole. And the timing is brutal: cabbage whites fly two or more generations per season, so the pressure runs from spring to autumn in most of Europe and North America. The fix that works isn’t spraying after the fact — it’s physically stopping the egg-laying in the first place, which is exactly what a mesh barrier does.
The three products get mixed up constantly, and the difference is the aperture. Butterfly netting at 5–7 mm mesh is sized for the cabbage white: the adult butterfly can’t pass, and the same net doubles as bird protection for fruit beds. Bird netting at 15–25 mm is too coarse — butterflies fly straight through it. Fine insect mesh (2 mm and below) stops smaller pests like cabbage root fly and aphids, but it costs more, breathes less, and is unnecessary if butterflies are your only problem. If your brassicas face butterflies and birds, butterfly netting is the one net that covers both; if you also fight root fly or aphids, that’s when the finer insect mesh earns its premium. Our insect and butterfly netting range covers both weights — butterfly-grade at 30–50 gsm for drape-and-frame use, finer insect meshes for the smaller pests.
Cover the day you plant out — not when you see the first butterfly. Egg-laying starts the moment the plants are in the ground, and a net that goes on a week late is already protecting a colony of eggs. One nuance that catches growers: if you’re covering ground that held brassicas last season, wait until any overwintering pupae have emerged (or turn the soil first) — a net over emerging pests traps them inside with your crop. Brassicas grown for leaves and heads don’t need insect pollination, so the net can stay on the whole season; lift it only for weeding and harvest, and put it straight back.
Three rules decide whether the net works or fails. Keep the mesh off the plants — butterflies can lay eggs through a net that rests on leaves, so use hoops, a frame or a cage and hold the mesh clear of the canopy. Leave slack for growth — brassicas double in size; a net pulled tight at planting becomes a cage that crushes the crop by midsummer, so drape with generous room or plan to raise the hoops once. Seal the edges completely — peg or weigh down every edge to the soil with no gaps; a fist-sized gap at ground level is a door, and cabbage whites find doors. Knitted HDPE is the right construction for this: it drapes softly over hoops without creasing, doesn’t unravel where you cut it to length, and survives being pegged, lifted and re-laid all season.
A net hides the crop as much as it protects it — problems build underneath unseen. Lift and inspect weekly: aphids that were already on the plants at covering time will multiply happily under a net, and slugs don’t care about mesh at all. Butterfly netting won’t stop cabbage root fly (that needs the finer insect mesh) or caterpillars that were already inside. And one more honest note from the field: on windy allotments the net itself becomes the hazard — a lightweight net rubbing against brassica leaves in a gale can scuff them worse than a butterfly would, which is why the hoops-and-slack setup matters twice over. At season’s end: fold the net dry, store it out of the sun, and it serves several more seasons — ours is 100% virgin HDPE with UV stabilization, knitted in our own factory, so the second and third year cost you nothing.
Butterfly netting is a spring-peak retail product with a reliable calendar: demand spikes at planting-out season in every temperate market. We supply it retail-ready — folded, bagged, your brand card and barcode — or in bulk rolls for allotment suppliers and agricultural distributors stocking brassica regions. MOQ is 2 tons with mixed specs in one container, so a butterfly-net order can share a shipment with bird net, insect mesh and shade net from the same knitting lines. Distributors who land their stock a month before planting-out season — not during it — are the ones whose shelves are full when the spike arrives. Send your target market and sizes via the contact page or WhatsApp and we’ll quote rolls or retail packs within 24 hours.
5–7 mm. The adult cabbage white can’t pass a 5–7 mm aperture, so eggs never reach the leaves. Bird netting (15–25 mm) is too coarse; fine insect mesh (under 2 mm) also works but costs more and breathes less — use it only if smaller pests like root fly or aphids are also a problem.
Yes — the 5–7 mm mesh that excludes butterflies also keeps birds off fruit beds and seedlings. It’s the one-net answer for mixed pest pressure in a vegetable garden or allotment.
The day you plant out — egg-laying starts immediately, and a net that goes on late protects eggs already on the leaves. If the ground held brassicas last season, turn the soil or wait for overwintering pupae to emerge before covering, so nothing hatches trapped inside.
No — netting excludes new egg-laying; it doesn’t remove caterpillars already feeding. Inspect and hand-pick the plants before you cover, then check under the net weekly for anything that slipped through.
They don’t need to be. Brassicas grown for leaves and heads (cabbage, kale, broccoli) have no fruit to pollinate, so the net can stay on all season — lift only for weeding and harvest, and replace it straight after.
Cover the day you plant, keep the mesh off the leaves, seal every edge — and check underneath weekly. Tell us your crop list and bed sizes and we’ll spec the butterfly netting for them, retail packs or bulk rolls.
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