What should I do with a vegetable bed over winter?

An empty vegetable bed over a British winter loses nutrients to leaching, has its surface structure destroyed by rain, and grows a crop of weeds ready for spring. Whichever covering option you choose matters much less than choosing one, but the tidying decisions before you cover it are where the real difference is made.

Step by step

1. Clear crop debris that harbours problems.Brassica stumps carry mealy cabbage aphid and whitefly through the winter. Blighted potato and tomato foliage carries disease. Club-rooted roots carry spores. All of that goes in the bin or council green waste, not on the heap.
2. Leave what is harmless and useful.Pea and bean roots stay in the soil with their nitrogen nodules — cut the tops off at ground level and leave the roots. Ordinary healthy foliage can be composted.
3. Weed the bed thoroughly before covering.Perennial weeds dug out, annuals hoed off. Covering weeds does not remove them; it just delays the reckoning until spring, when you have less time.
4. Choose a covering and apply it.A thick mulch of compost or well-rotted manure, a sown green manure, or a sheet of cardboard, membrane or old compost bags weighted down. All four beat bare soil.
5. Mulch with compost if you want the simplest option.A layer of compost or well-rotted manure over the surface protects the soil, feeds it, and is pulled into the soil by worms over winter. On a no-dig bed this is the whole winter routine.
6. Sow a green manure if the bed is clear early enough.Sown in late summer or early autumn, a green manure holds nutrients that would otherwise leach, protects the surface and adds organic matter when it is cut down or dug in in spring. Field beans, grazing rye and winter tares are the usual autumn choices.
7. Cover with cardboard or membrane if the bed is clear late or weedy.Weighted-down cardboard suppresses weeds, keeps rain off the surface, and rots down. Membrane does the same and is reusable but adds nothing to the soil.
8. Keep some beds in production.Overwintering crops — garlic, onion sets, broad beans, autumn-sown peas, winter salads under cover — occupy the ground usefully and are ready far earlier than spring sowings.
9. Do not dig heavy soil in autumn if you can avoid it.The traditional autumn dig on clay, leaving it in ridges for frost to break down, still has a place. On most soils, covering and leaving alone does more good than turning it over.
10. Plan the bed while it is empty.Winter is when the rotation is decided and the seed ordered. Write down what was in the bed this year and what follows it.

Tips

• Autumn leaves make an excellent free winter cover on a bed, weighted with netting or a few boards so they do not blow away.
• Do not lift the cover repeatedly to look. The point is to leave the soil undisturbed.
• Slugs and voles both shelter under permanent covers. Lift and check before planting in spring rather than being surprised.
• Clear the bed in stages as crops finish rather than all at once in November — a bed covered in September has three more months of protection.
• A green manure with deep roots, like grazing rye, is genuinely useful on compacted ground.

Common mistakes

• Leaving brassica stumps standing all winter — They carry mealy cabbage aphid and whitefly straight into the following crop. Pulling them is one of the highest-value winter jobs.
• Leaving the soil bare — Winter rain leaches nutrients and destroys surface structure, and by March the bed is capped and full of weed seedlings.
• Sowing a green manure too late — It needs to establish before growth stops. A sowing in November mostly fails and leaves you with bare soil anyway.
• Composting diseased material — Club root spores, blight-infected foliage and white rot all survive a domestic heap and return with the compost.

Alternatives

• Compost or manure mulch: Simplest and best for soil life. Protects the surface, feeds the bed, needs no timing. The standard no-dig approach.
• Green manure: Holds nutrients that would otherwise wash away and adds organic matter. Needs sowing early enough in autumn to establish, and clearing before the next crop.
• Cardboard or membrane: Best where the bed is weedy or cleared too late for a green manure. Suppresses weeds well; cardboard also feeds the worms.
• Overwintering crop: Garlic, onion sets, broad beans, winter salads. Uses the ground productively and gives an early harvest, at the cost of tying the bed up.
• Bare soil: The default and the worst option — nutrients leach, structure is damaged by rain, and weeds establish. Only defensible on heavy clay being deliberately frost-weathered.

Questions people ask