Netting Cabbages Without Locking Out Pollinators

Match the Net to the Cabbage Stage

Insect netting does two useful jobs in a cabbage bed: it keeps flea beetles, cabbage white butterflies and aphids off the plants, and it stops pigeons from shredding young leaves. Neither job requires netting to cover the crop for the whole season. Cabbages are grown for their heads, not their flowers, so pollinator access matters mainly for nearby fruiting crops and for the cabbage's own later phase, when unharvested plants send up flower stalks. The simplest way to organise the task is to treat netting as a seasonal barrier with planned openings, not as a permanent cage.

Start by deciding what the net is for. A fine mesh of about 1mm to 1.5mm protects against flea beetles and aphids. A coarser mesh, often around 4mm to 7mm, keeps butterflies and birds out but lets small insects through. If flea beetle has been a problem, choose the fine mesh and expect reduced airflow and slightly warmer conditions under it. If the main threat is butterflies and pigeons, the coarser net is easier to live with and allows more air movement across the bed.

Put the Frame Up Before Planting

The most common reason netting fails is that it is added after the crop has already been attacked. Build the support first, then plant into it. Hoops, timber frames or a simple cage of posts and crossbars keep the net off the leaves. Net resting directly on cabbage leaves lets butterflies lay eggs through the mesh and gives flea beetles a sheltered edge to work along. A gap of at least 15cm to 30cm between the net and the plants is enough for most kitchen-garden beds and makes weeding and inspection possible without dismantling everything.

Choose the access method

• Lift-off panels: pegs or clips hold net panels over each bed. Best for small beds where you inspect plants often.
• Hinged side flaps: one long side opens while the rest stays secure. Good for rows, and quick for harvesting.
• Full cage with a zipped or overlapped door: more structure, but worth it where cabbage whites are persistent.

Bury or weight the net edges. Cabbage white butterflies are small and persistent, and flea beetles can walk in from loose soil edges. Use soil, sandbags, pegs or weighted battens along the whole perimeter. A net that is pegged only at the corners leaves gaps along the sides.

Sequence the Season Around the Crop

Stage 1: From transplanting to established growth

Cover the bed immediately after planting. Young cabbages are most vulnerable to flea beetle and pigeons, and the net should be closed before the first butterflies appear. Water through the mesh or open a flap briefly in the morning, then close it again. Check plant spacing before you cover: cabbages need room for the head to develop. A tight planting under fine mesh creates humid, still conditions that favour aphids and fungal problems.

Stage 2: Through the main growing period

Keep the net closed during the flight period of cabbage white butterflies, which varies with your region and local weather. Watch for butterflies hovering near the bed, and check the underside of leaves whenever you open the net. A weekly inspection of a few plants is more useful than a fixed calendar. If you find eggs or small caterpillars, remove them before closing up again. Aphids can build up under netting, especially on plants that are well fed with nitrogen, so open the bed briefly on calm days to inspect and to let beneficial insects move out.

Stage 3: From head formation to harvest

Once heads are firm, the crop is close to harvest and the pressure from caterpillars matters less in the final weeks. You can remove the net for easier harvesting once the head is filled out, but leaving it on keeps pigeons off and protects the outer leaves. If you plan to harvest over several weeks, keep the net in place and open it only for cutting.

Where Pollinators Fit In

Cabbages are insect-pollinated in the sense that their flowers are visited by bees and other insects, but they are also self-fertile and wind-assisted. You are not growing a cabbage for its flowers. The practical pollinator question is about the rest of the garden: fruiting crops such as beans, tomatoes, courgettes and berries need insects moving freely. A net over a cabbage bed does not need to enclose those crops, and a separate bed plan keeps the two needs from conflicting.

If you want to save seed, the plan changes. Left to flower, cabbage plants produce tall stems of yellow flowers that bees visit readily. At that stage, remove the net during the day and accept some pest pressure, or switch to a mesh coarse enough to allow pollinators through. Seed saving from brassicas also requires isolating flowering plants from other brassicas, because they cross readily. That isolation is a separate decision from pest netting.

Materials, Fit and Useful Additions

The netting itself is the key purchase. Woven or knitted mesh with a stated hole size is more reliable than a generic garden net where the mesh is unlabelled. Check the width against the frame, and buy enough length to allow slack over the crown of the plants. A net pulled tight over hoops can tear at the corners in wind. Brassica collars placed around the stems at planting are a useful companion to netting, because they stop cabbage root fly from laying eggs at the stem base. Yellow sticky traps hung inside or near the bed help you see which flying insects are present, but they do not replace a closed net.

For the frame, hoops or timber posts should be tall enough that the net clears the mature plants. A simple hoop-and-net system is the fastest to move between beds, while a timber cage suits a permanent cabbage patch. Clips, pegs and weights are small purchases that make the difference between a net that stays put and one that flaps open in the first breeze.

Keep the Routine Simple

A sensible sequence is: frame first, fine or coarse mesh chosen to match the pest, edges weighted all round, net closed from planting through head formation, and a short inspection each week. Open the net for weeding and checking, then close it again the same day. Leave pollinator-friendly crops outside the cabbage cage, and only consider opening the net for pollinators if you are deliberately letting cabbages flower for seed. The result is clean, tender heads with less reliance on sprays, and a bed that still fits into a garden where bees and butterflies have their own space.