Beetroots in Cambridge

Work the bed deeply and rake it to a fine, stone-free tilth around 15th March - 5th April. Avoid fresh manure, which makes roots fork and split.

Sow seeds directly in drills around 29th March - 14th June, to a depth of 2–3 cm. Sow a new batch every 21 days if you want a longer harvest, and water the row in well after sowing.

Cover the sown row with insect-proof mesh from 12th April to keep out flea beetles and leaf miner. Seal the edges well so flies cannot get in underneath.

When the seedlings are large enough to handle, from 27th May, thin them carefully to leave one strong plant every 10 cm. Snip the extras at soil level rather than pulling them, to avoid disturbing the roots you are keeping.

From 3rd June through to 28th October, keep the soil evenly moist so the roots stay tender and round. Water during dry spells and give a light feed only if growth looks poor, because overfeeding can make the crop leafy at the expense of the root.

Lift roots from 15th July once they are about golf ball to tennis ball size, or leave them longer for bigger roots. Harvest can continue through 27th November, and roots can stay in the ground for a while in mild weather if the soil drains well.