Sprouting broccoli – calabrese (or green), purple and white varieties.
Sowing to harvest time: 12 to 16 weeks for calabrese; 40 weeks for purple and white varieties.
Yield: Calabrese, up to 0.9kg (21b) per plant; other varieties, average 0.45 kg (1 lb) per plant.
Climate preferred: Cool temperate to sub-tropical.
Aspect: Open, but sheltered from strong winds.
Soil: Heavy, firm and rich in organic matter.
Broccoli is closely related to the cauliflower, but it is very much easier to grow. It can withstand more heat and more cold than the cabbage. If you are growing calabrese, make use of the latest hybrids which mature rapidly and give huge yields.
Sowing and planting
The seed should be sown thinly in rows 1.3 cm (2 in) deep. Calabrese (green sprouting broccoli): sow in mid- or late spring and thin early to prevent the plants from being weakened through overcrowding. When the seedlings are 7.5 cm (3 in) high, move them to their permanent positions with 45 cm (18 in) between the plants and 60 cm (2 ft) between the rows. Before setting the plants in their final positions, give the plot a dressing of vegetable fertilizer at the rate of 135gm per sq m (4oz per sq yd).
When transplanting, fill the holes with water. Allow to drain. Then set the plants 2.5 cm (1 in) deeper in the holes than they were in the seed bed. Finally firm the soil around the plants with your fingers. Purple sprouting broccoli is the hardiest of the broccolis and grows well in cold areas and on heavy clay soils. Sow the seeds as before in late spring and transplant the seedlings when they are 7.5 cm (3 in) high to produce a crop from early winter to late spring, depending on the variety. White sprouting broccoli, if sown at the same time, will give a crop between early and late spring, depending on the variety.
All broccoli requires regular hoeing of the soil to keep down weeds. The soil should also be kept well watered in dry spells. Feed with nitrochalk at the rate of 34 gm per sq m (1oz per sq yd) in rings around the plants four weeks after transplanting. With purple and white sprouting broccoli, draw up soil around the stems in autumn to prevent their being toppled by winter winds. Alternatively provide each plant with a bamboo stake.
Pests and diseases
Birds (especially pigeons), aphids, caterpillars, club root and root fly.
The ‘spears’ should be cut when they are small and not too far developed: at a point just before the flower buds have opened. Cut the main centre spear first and then all the side spears. With the calabrese hybrids, the centre spear usually takes the form of a sizeable head, not unlike that of a cauliflower. Keep cutting the spears as they develop and never let the plant flower or the production of fresh spears will stop. Store by freezing.
This is a very useful and hardy green vegetable and is very useful when grown for winter and spring use. The plants like a good soil, but not too rich, as this will make them soft, and they will be killed in the severe weather. Farmyard manure should be added before the seeds are sown. The best crops are obtained when grown on heavy loam.
If the plants are to be harvested in autumn, the seeds should be sown in mild heat in February and March, and the seedlings planted out in April and May, setting them 3-4 inches apart. The seeds may be sown broadcast or in drills 9 inches apart, and about 1 inch deep. When they are finally transplanted they should be in rows 2 feet 6 inches apart, 2 feet between each plant.
Some of the best varieties for the amateurs garden are: Walcheren. Winter White.
Purple Sprouting. White Sprouting.