Growing Cool-Season Crops Indoors

While it’s too early to plant outdoor vegetable gardens, now is the perfect time to start growing cabbage, broccoli, lettuce, onions, radishes, peppers and early tomatoes indoors.

To prevent diseases associated with growing in a warm, humid environment, Johnson County Extension horticulture agent Dennis Patton suggests using a seed starting mix or high-quality potting soil.

In order to produce short, stocky transplants, starter plants need artificial light. Fluorescent shop lights, positioned within three-to-six inches of the plants, work best. However, Patton says they need to be kept on a majority of the time.

There are three phases or stages to starting seeds: germination, growth and hardening off. Patton says hardening off involves moving the plants outside to acclimate to real-world conditions over a seven-to-10 day period.

K-State Research and Extension has a number of publications and videos available online to help gardeners of all skill levels. To find out more, go to: or stop by any county or district Extension office.