Germination temperature
Optimum about 21-27 °C (70-80 °F); germinates from about 16 °C to 32 °C (60-90 °F).
Vegetable growing guide
Brussels sprouts germinate as easily as cabbage, but the plants need a long season and cool weather while the sprouts form. This guide covers sowing, timing the crop so sprouts mature in the cold months, and where in India it can succeed.
Optimum about 21-27 °C (70-80 °F); germinates from about 16 °C to 32 °C (60-90 °F).
About 6 mm (1/4 in), no deeper than 12 mm (1/2 in).
About 5-8 days at 18-21 °C (65-70 °F).
Cover the seed; full sun for seedlings.
None needed.
Transplants are usual: 6-8 week old seedlings with 3-4 true leaves.
Sow dry seed in trays or a raised nursery bed. Plan backwards from the cool season: the crop takes about 80-118 days from transplanting, plus 6-8 weeks in the nursery.
Not needed. Brassica seed takes up water readily.
Not needed. Seed germinates without a cold period.
Not needed; it can make the small seed harder to sow evenly.
Optimum soil temperature is 21-27 °C (70-80 °F), with germination possible from about 16 to 32 °C (60-90 °F). In hot weather put the nursery in light shade so the surface does not overheat.
About 6 mm (1/4 in) deep, and no more than 12 mm (1/2 in).
Fine, free-draining seed compost or a raised nursery bed. In the field, soil pH about 6.2-6.8.
Keep evenly moist until emergence, then water as the surface begins to dry.
Seed is covered and germinates in the dark; give seedlings full sun at once to keep them compact.
About 5-8 days at 18-21 °C (65-70 °F); faster in warm soil, slower in cool soil.
Plant out 6-8 week old seedlings with 3-4 leaves and a root ball that holds together. Establishment is the most sensitive stage, so transplant in the evening or on a cloudy day and water in well. Space plants 45-60 cm (18-24 in) apart in rows at least 90 cm (36 in) apart.
Plants first build a tall stem with large leaves; sprouts form later in the leaf axils, starting at the bottom. Growth is best between about 10 and 27 °C (50-80 °F), with an optimum near 24 °C (75 °F) and 35 °C (95 °F) as the upper limit.
Sprouts are best when days are about 18-27 °C (65-80 °F) and nights cool. Sprouts that mature in hot weather are loose and tend to be bitter, so time planting so the sprouts form in the coolest months.
Cause: sprouts maturing in hot weather. Fix: plant earlier so sprouts form in cool weather, choose an early variety where the cool season is short, and water regularly.
Cause: late planting, so the cold season ends before sprouts fill out. Fix: transplant on time and top the plants (see tips).
Cause: heat and drought during sprout development. Fix: grow as a winter crop; flavour improves after cool nights.
Cause: diamondback moth, cabbage looper and cabbage worm larvae. Fix: check plants weekly and use Bt (Bacillus thuringiensis) or nets.
Cause: cabbage aphids, which move into the plant centre in cold weather. Fix: inspect sprouts early and wash off or treat colonies before sprouts close.
In the north Indian plains, Brussels sprouts are a winter crop. In trials at Gurdaspur, Punjab, planting on 20 October gave the best growth and yield and planting on 10 November the lowest, so sow the nursery 6-8 weeks earlier, from late August to early September. The long cool season of the hills suits the crop best; hot, humid lowlands rarely give firm sprouts.
Early varieties mature in about 80-93 days from transplanting, late ones in 105-118 days. Where the cool season is short, the early ones are safer.
Pinch out the growing tip when the lowest sprouts are about 6-12 mm (1/4-1/2 in) across. Sprouts then fill out evenly in about 30 days; in Utah trials topping raised the usable harvest of most varieties, for example from 39% to 56% in Dagan.
Pick sprouts when they are firm and before they open, twisting them off from the lowest first. Plants tolerate frost, but sprouts discolour after nights near -7 °C (20 °F).
Sow Brussels sprouts early enough that the sprouts form in the coolest weeks of your season.
Yes, as a cool-season crop. In the northern plains plant out around mid to late October so sprouts form in winter; Punjab trials found 20 October better than 10 November. Hill areas with a long cool season are the most suitable. In hot, humid lowlands sprouts usually stay loose.
Sprouts that develop in hot weather are less firm and can taste bitter. Plant earlier so the sprouts mature in cool weather, or choose an early variety.
About 6-8 weeks in the nursery plus 80-118 days from transplanting, depending on the variety, so roughly four to five months in total.