Autumn Jobs for a Productive Allotment Plot

Why Autumn Is the Quiet Engine of the Plot

By late September most allotments look well used and slightly frayed at the edges. It is tempting to drift away until spring, but the six weeks from now until the first hard frost are the most valuable weeks of the year for the soil. Ground that is still warm — and it usually is until mid-November in most of the UK — keeps roots, worms and soil life working long after the tops of your crops have given up. Every barrow of compost spread now gets incorporated by worms through the winter, so you start spring with a plot that is already ahead of itself rather than a wet, weedy mess that needs rescuing.

Clear Spent Crops, but Clear Them Properly

Clearing is not just pulling things up. It is deciding what goes on the compost heap, what goes in the green waste bin, and what gets left in the ground.

• Blighted foliage — potato and tomato haulms with brown or black patches — should never go on your heap. Bag it and put it in the green waste collection, then wash your hands and clean your tools before moving to the next bed.
• Runner and climbing beans can be cut at ground level once cropping slows. Leave the roots in; the nitrogen nodules break down in place and feed whatever follows.
• Asparagus should be cut down to about 5cm stubs once the fern yellows, usually in October. Do it too early and you rob the crowns of the energy they are storing for next spring.
• Brassica stalks and sweetcorn stems are woody. Chop them roughly with a spade, and put them in a separate pile or bin to rot down for a year or two before they earn a place on the beds.
• Parsnips can stay put and be lifted as needed, topped with a thick mulch of compost to keep the frost off. Maincrop potatoes should already be lifted and drying in a shed.

Do not leave bare, clumpy ground sitting through the rain. Soil stripped of roots is soil that washes away, and winter rain leaches nitrogen out of it faster than you would believe.

Feed the Ground and Let It Rest

Spread a 5cm layer of well-rotted compost or manure over any bed that is now empty, and simply leave it. You do not need to dig it in — the worms will do the work, and the layer protects the surface from pounding rain and capping. Where you garden on heavy clay, this is the single best thing you can do all year.

Two rules worth keeping: never lime and manure the same bed in the same season, and put your manure where the hungry crops will go next year. Peas and beans, courgettes and brassicas all appreciate it. Beds earmarked for carrots and parsnips are better left with a light compost dressing, or you will grow forked roots and a forest of green tops.

Sow Green Manure Before the Frosts

If you have no compost to spare, sow a green manure instead. It is cheap, quick, and it holds the plot together over winter.

• Winter tares — sow by the end of September. Fixes nitrogen, tolerates most soils.
• Grazing rye — sow up to the end of October. Brilliant on heavy ground and for soaking up leftover nutrients.
• Field beans — sow up to mid-November in rows 20–25cm apart. Hardy, deep-rooted and good for breaking up compaction.
• Phacelia — tender, so it dies in the first real frost, but sown in early September it gives excellent quick cover and lovely flowers for late bees.
• Mustard — fast and cheap, but it belongs to the brassica family. Never sow it where cabbages, sprouts or broccoli are going next, as it can carry clubroot on.

Come February or early March, chop the tops down with a spade or shears and leave them on the surface as a mulch, or fork them in lightly. Do this before anything sets seed or turns woody, or you will spend spring pulling it out again.

Tidy the Frame: Shed, Beds and Paths

A dry hour spent on the structure of the plot now saves several wet hours later. Clear greenhouse glass and guttering, and check water butts for leaks and leaves before the winter rains fill them. Wash pots in hot soapy water and store them dry and stacked, so you are not scrubbing them in March with cold fingers.

Sort the shed while you still have light to see by. Sharpen the hoe and the spade edge, oil the handles, and hang everything off the floor on nails or hooks. Stakes, canes and netting should be bundled by size and tied. Replace broken ties, and check the shed roof and felt before the worst of the weather arrives. Then put a chair in there and use it — a potting shed or allotment retreat that is pleasant to sit in is a shed you will actually keep tidy.

Plant Now for a Head Start

Autumn planting gives you crops before you have even thought about spring sowing.

• Garlic — plant cloves pointed end up, 15cm apart, 2.5cm deep, from October in mild areas and into November elsewhere.
• Overwintering broad beans — sow in November for the earliest pods of the year, with a little fleece ready for hard frost.
• Autumn onion sets — plant by mid-October on ground that was manured for a previous crop, not freshly enriched.
• Rhubarb crowns and bare-root fruit bushes — plant while the soil is still workable, then mulch and walk away.

Finish the season by sketching a simple four-bed rotation on paper and noting what cropped well and what did not. Ten minutes with a pencil now is worth a whole panicked morning in spring, wondering where the beans went last year.