How do I grow purple sprouting broccoli, and when do I pick it?

Purple sprouting broccoli occupies a bed for the best part of a year, which puts a lot of people off. What it gives back is a harvest in February, March and April, when almost nothing else in the garden is producing and shop vegetables are at their worst. On an allotment it is one of the best uses of ground there is.

Step by step

1. Sow in spring, in a seedbed or modules.Traditional varieties want a long season and are sown from mid-spring. Sowing late is the commonest reason a plant fails to build enough size to crop well the following spring.
2. Plant out in early summer, firmly.Move plants when they have four or five true leaves. Heel them in hard — this is a tall plant that has to stand through winter gales.
3. Space at about 60cm each way.It makes a big plant. Crowded plants are drawn, unstable and produce far fewer spears.
4. Net it from the day it goes out.Cabbage whites in summer, pigeons all winter. A plant that has been stripped twice will not have the reserves to crop in spring. Fine mesh in summer, 2cm bird netting through winter.
5. Stake and earth up in autumn.Wind rock over winter loosens the roots and costs you the crop. A cane and a tie plus soil drawn up round the base is enough.
6. Feed in late winter, not late autumn.A nitrogen feed as growth restarts in late winter supports spear production. Feeding in autumn produces soft growth that the frost damages.
7. Pick the central spear first.The main spear at the top of the plant is ready first. Cutting it releases the side shoots — leave it and the plant produces far fewer spears overall.
8. Pick every two or three days while buds are tight.Take spears about 15cm long with the flower buds still closed and dark. Once the buds open into yellow flowers the spear is tough and the plant starts winding down.
9. Keep picking to keep it cropping.A well-managed plant produces spears for six to eight weeks. Leaving spears to flower shuts it down within a fortnight.
10. Clear the plants when they run to flower.Once flowering takes over, dig them out. Chop the stems up before composting — a brassica stem takes a long time to break down whole.

Tips

• Modern early varieties can crop before Christmas and some fast types crop in the same year they are sown, which suits a smaller garden with no space to spare for a year.
• The leaves are edible and good, so a plant that never sprouts well still gives you winter greens.
• Yellow flowers on a few spears do no harm to the plant — pick them off and keep going.
• Purple sprouting is one of the hardiest vegetables there is and generally shrugs off a hard British winter, which is exactly why it is worth the ground.
• It flowers beautifully if left, and is excellent for early bees — worth leaving one plant when you clear the rest.

Common mistakes

• Sowing too late — The plant needs the whole summer and autumn to build size. A midsummer sowing produces a small plant and a token crop.
• Leaving the central spear to grow bigger — The plant will not release its side shoots until the main spear is cut. Cutting it early is what multiplies the crop.
• Not netting through winter — Pigeons will destroy a bed of sprouting broccoli in a hard spell, and it takes a year to grow a replacement.
• Letting spears flower — Open flowers signal the plant to move to seed production, and the harvest ends weeks early.

Questions people ask