Broccoli

The broccoli you are likely to grow in the UK are sprouting varieties whereas the large green heads you buy in the supermarket are strictly calabrese.

Location
Pick a sunny or partially shaded spot. Ensure the site is not low lying or prone to flooding as your plants will need to survive the winter in situ. Do not choose a site that has been used for brassicas (cabbage, cauliflower, kale, swede) in the last two years. This will reduce the chances of your plants suffering from club root and cabbage root fly.

Soil
Broccoli like firm, rich, heavy soil preferably not clay. Dig in some well rotted compost several weeks before planting.

Direct
Seeds should be sown 15cm (6in) apart in rows up to 90cm (35in) apart. Cover seeds with a little over 1cm (½in) soil and water in. In 12 days' time you should thin your germinated seedlings to about 50cm (19½in). If you use a poly tunnel to heat the soil, you can sow up to four weeks earlier. Ensure that the tunnel is in place two weeks prior to sowing.

Indoors
Broccoli can be sown in modules or a seedbed under protected conditions and transplanted to gain an extra few weeks' growing time. However; it does prefer a firm root, so you should transplant seedlings while still young.

Aftercare
Unless you have sandy soil you should not need to water very often except during high spells or when the heads are forming. Give them a feed of a general purpose fertiliser when the seedlings have 6 or more leaves.

Mulching around the stems with garden compost will help the plants to retain moisture. Alternatively use a weed suppressant fabric which will reduce evaporation and reduce the need for manual weeding.

Harvesting
For best results, begin harvesting heads before the flowers open. Picking regularly will encourage the formation of side shoots. Cut the stalks half-way down with a knife being careful not to harm the plant.

Storing
Broccoli heads freeze well; blanch your harvest in salted water for 3 minutes, drain and cool for 5 minutes. Try to remove as much water as possible before freezing. Heads will keep in the fridge for about a week, but are at their best picked and eaten on the same day without refrigerating.