What initiates the sprout formation on Brussels sprout plants?

Hi Jane, Brussels sprouts are a cool season crop so best planted late in summer, early autumn, they do not do well in temperatures above 26 degrees C. The key to initiating sprouts would be time, cooler weather, a soil rich in organic matter and consistent watering throughout the season. They are a long term crop, taking up to 100 days from seedling to harvest. Don't plant plants too closely together, make sure plenty of organic compost and composted plant material is dug into the soil before planting, Tui Chicken and Sheep pellets are an ideal addition at planting time. They prefer heavy clay soils rather than light sandy soils and consistent watering, especially in the warmer months, do not let plants dry out, mulching around plants in the warmer months will help conserve soil moisture. Feed with a balanced fertiliser such as Tui Vegetable Food every 6 weeks or Tui Performance Naturals Tomato and Vegetable fertiliser every 8-10 weeks. Brussel sprouts are harvested in the cooler months, autumn and winter, grow them as you would cauliflower and cabbage. Lianne, Tui Team.