Brussels sprouts

Looking after it

Water: Brussels sprouts need normal watering. Water young plants regularly so the soil never dries out. Once they are settled, water only in dry weather. A thick mulch keeps the soil moist. Feeding: They need rich soil. Dig in compost the autumn before. On poor soil, or if growth is slow, give a fertiliser rich in nitrogen in early to mid summer.

Harvest and keeping

Start with the lowest sprouts, once they are firm and about the size of a walnut. Snap them off with a downward tug and work your way up the stem. When the sprouts are done, cook the top like spring greens. A whole stem, once cut, keeps a few days standing in water or hung in a cool, frost-free shed. Pick off the sprouts as you need them. You can freeze them too, after a quick dip in boiling water.

What can go wrong

• Loose sprouts. Loose soil gives open, leafy sprouts instead of tight buttons. Firm the soil before planting and pile soil around the stems in late summer. Stake tall plants in windy places.
• Mealy aphids. Grey, waxy aphids gather on the leaves and inside the sprouts. Squash or wash off small groups early. Remove leaves that are badly affected.
• Club root. The plants stay small and wilt on warm days. Their roots are swollen and knotted. There is no cure and it stays in the soil for years, so add lime to acid soil until it reaches at least pH 6.5. Move these crops to a new bed each year and start plants in pots, so they go out with strong roots.