Red cabbage: Sowing, planting and harvest calendar

Sow red cabbage under cover at the time recommended for the variety and your climate. Use small pots or modular trays with drainage holes, filled with seed compost. Sow about 1 cm deep, or as directed on the packet, then water to moisten the compost without waterlogging it.

Keep the seeds in a bright place at a temperature suited to germination and ventilate the growing area. After germination, thin to one vigorous plant per module. Maintain consistent moisture. Once the plants are sufficiently developed, gradually harden them off before transplanting to the vegetable garden at the recommended spacing for the variety.

Label batches to distinguish early varieties from those intended for storage, as their growing times and planting dates may differ. Distribute the seeds without crowding to reduce competition from emergence. Once seedlings appear, aim for compact growth in good light rather than long, fragile stems. Check the roots before transplanting: a well-formed root ball holds together, but plants should not spend a long time cramped in their cells. Prepare their garden space before they reach that stage.

Adjust outdoor sowing time for red cabbage to the variety, desired harvest season and climate, following the packet. Prepare a fine, weed-free seedbed in a sunny spot with fertile, well-drained soil.

Sow about 1 cm deep, or as directed on the packet. In a nursery bed, thin the young plants and transplant them to their final position once sufficiently developed. If sowing directly in their final position, thin to the spacing recommended for the variety: sowing distance does not replace final plant spacing.

Keep the soil moist without waterlogging it. Watch for slugs and caterpillars and identify problems before taking action. Suitable insect-proof mesh can prevent butterflies from laying eggs on young cabbages.

Mark rows with the variety and date. In a nursery bed, leave enough room to remove competing weeds without pulling up neighbouring cabbages. Moisten the bottom of the drill before sowing if it is dry, then water with a fine rose so the seeds stay in place. If using mesh, fit it from the start and allow enough height for growth without pressing the leaves onto the soil.

Transplant young red cabbages once sufficiently developed and when outdoor conditions suit the variety. Gradually harden off plants raised under cover. Choose a sunny spot with fertile, well-drained soil and include other brassicas in your crop rotation.

Water the plants before moving them and handle the root balls without damaging the roots. Set them with the lowest leaves close to the soil surface, firm the soil around the roots and water thoroughly. Follow the recommended distances between plants and rows for the variety rather than one spacing for every cabbage.

Then maintain consistent moisture without waterlogging the soil. Watch for slugs and caterpillars; suitable insect-proof mesh can reduce egg-laying by butterflies. Crop rotation helps reduce the build-up of soil problems, but does not replace pest monitoring.

Prepare holes and protective covers before taking out the root balls to limit exposure to air. Choose sturdy plants rather than ones with very elongated stems. After watering, check each plant is stable and fill air gaps around the root ball with a little soil. Allow room for the large leaves to develop and keep access between rows for watering and checking for caterpillars.

Harvest red cabbage when the head is well formed and firm. Timing depends on the variety, sowing and climate, and is not always limited to autumn. Cut the stem below the head with a clean, sharp knife, keeping a few outer leaves to protect it.

For use soon after harvest, keep the cabbage in the refrigerator. Long-term storage requires a suitable variety and cold conditions with high humidity rather than a dry cellar. Storage life depends on the condition of the heads and how they are stored. Check them regularly and discard any that deteriorate.

Gently press the head with your hand to judge firmness without damaging it: diameter alone does not show maturity. Harvest the most advanced heads first. Heavy rain near maturity can encourage splitting, so do not leave a ready head in the garden unnecessarily. For storage, select whole, healthy heads without splits or bruises. Remove only damaged outer leaves rather than stripping the head excessively, and set aside those needing prompt use. A cabbage already cut up in the kitchen needs shorter storage than an intact head.