Organic Gardening:

How to grow organic Broccoli

Good enough for an American president!

Broccoli Brassica oleracea Italica group Family: Cruciferae (Group 2)

Broccoli is a much-maligned vegetable, which is a pity because if it is grown well and cooked as soon as it has been picked, it is not only very nutritious, but delicious, too. It's important not to overcook it, though. Soggy broccoli is absolutely dire.

This page covers white and purple sprouting varieties of broccoli. Heading broccoli is dealt with on the page on cauliflower, and green sprouting broccoli on the page on calabrese.

Site and soil

Choose an open, unshaded site with fertile, well-drained and moisture retentive soil, which should be slightly acid (min pH 5.4, but see note on clubroot - add lime if necessary to adjust pH). Brassicas have a high nitrogen requirement and also need very firm soil. To ensure sufficient nutrient levels, it is best to topdress or apply a liquid feed such as seaweed fertiliser during growth.

Because brassicas are prone to soil infections, for example, Clubroot, it's important to use a minimum 3 year rotation plan.

Perennial cauliflower (formerly broccoli) 'Nine Star Perennial' should be sown in March to April, transplanting to 1m by 500cm (3'x18"). The bed should be moved to a new site after 3 years' cropping. Heads are produced around February to March each year. All must be cut to keep plants productive in following years.

Ideal pH 6.2-6.6

Cultivation

Sow in a seed bed unless soil is heavy, in which case use seed trays or modules to minimise root disturbance. Sow 2-2.5cm (¾-1") deep, spacing 7.5cm (3") apart in the row. Transplant at about 10cm (4") tall or when the first true leaves develop to follow legumes or onto a site which was manured the previous Autumn.

On light soils, plant into drills 8cm (3") wide by 10cm (4") deep and earth the plants up as they develop until the soil is level, otherwise on the flat. Plant firmly enough that pulling on a leaf results in it tearing. Use brassica collars to prevent root fly.

Transplant 60cm each way (2'x2').

Water after transplanting and daily in dry weather for 3-4 weeks, about ¼ pint per plant.

Hoe to keep weed free. Mulch to conserve moisture and suppress weeds. Catch crops may be sown between rows early on, eg. radishes, lettuces, seedling salad crops.

Water up to 4 gallons per sq yard per week in dry weather. The minimum watering requirement is a single heavy watering 10-20 days before maturity.

Stake firmly in autumn, earth up as plants grow. Protect from pigeons in winter.

Harvest the central spear first, followed by the side shoots. Picking starts when spears are the size of large walnuts. Regular cropping increases yield.