If started indoors, the seed should be sown in a protected location in peat pots or seed flats, 4 to 5 weeks before transplanting. It will takes 90 to 95 days to reach full maturity.
Transplant the seedlings to the permanent garden location when space and time allow, but at least 90 to 100 days before the first frost date for your area.
For summer harvest, you must plant transplants of an early, heat-resistant variety in very early spring. Sprouts maturing in hot weather or under dry conditions are more likely to develop bitterness. Fall production is the most practical and rewarding in most parts of the country.
Space plants 24 to 36 inches apart in the row, or 24 inches in all directions in beds. Cover seeds 1/4 to 1/2 inch deep and transplant the seedlings when they are about 3 inches tall. Do not allow transplants to become stunted in the flats before transplanting.
Moisture during the summer is critical to keep the plants healthy Brussel sprouts are not very drought tolerant, plants will become stressed and growth will be impeded. Inexpensive water timers are available.
Brussel Sprouts have high nitrogen and boron requirements.
For a good harvest- Follow a nitrogen fixing crop in your rotation -such as beans or peas.
Osmocote ,a time released fertilizer works well and has become very popular , lasting for up to 4 months. Osmocote is however , expensive. An organic fertilizer such as fish emulsion can be used bi-weekly, soils will always be improved with the addition of well rotted manure or other organic matter.
Brussel Sprouts share a symbiosis with Potatoes, Sage, Hyssop, and Thyme and have an antagonistic relationship with Strawberries and Rosemary. See Companion Planting
Harvesting should commence when sprouts are about 1 inch in diameter. Start at the bottom and harvest upward. If harvest is delayed until the lower leaves turn yellow, the sprouts will be tough and off flavor. The flavor is actually improved by a minimal exposure to light frost.