Container-grown plants require more frequent fertilization than field-grown plants because of the limited space within the container for drawing nutrients. Fertilizers can be mixed with the growing media before filling the container and can also be applied as a nutrient solution. Nutrient solutions can be made by dissolving soluble fertilizer such as 10-20-10, 12-24-12 or 8-16-8 in water following label directions. The nutrient solution is applied once a day when the plants are watered. How often you water may vary with vegetables, but once a day is adequate. Leach the unused fertilizer nutrients from the potting mix once a week by applying tap water only. It is also very important to water occasionally with a nutrient solution containing micronutrients such as copper, zinc, boron, manganese, and iron and follow label directions in order to give plants the right amounts.