Add fertilizer and water while planting, and try maintaining the temperature up to 75°F for best results. The sprouts dwell well in sun or partial shade, and since they are top heavy, keep them from planting in areas that have strong winds.
Don't let them grow too large, else they may start cracking, and become bitter. You can also pluck them, by taking off the yellowing leaves, and gently twisting the sprouts off.
Before transplanting or sowing seeds, it is recommended to fertilize the planting site, by adding 10-10-10 fertilizer to it. Once the sprouts start growing, add 1 tbsp (15 ml) per plant of 5-10-10 fertilizer, or you can also use one large handful of good compost.
Like other cabbage family members (cabbage, kale, cauliflower, and broccoli), Brussels sprouts are also susceptible to some common soil borne fungal and viral diseases like club root caused by aphids and cabbage worms. You can use row covers to deter pests like flea beetles, cabbage worms, and root maggots from damaging the sprouts.
Since Brussels sprouts have shallow root system, ensure that you don't damage its roots while maintaining the soil. For best yield, apply nitrogen fertilizer after every three weeks during its growing season and water frequently.