How to Grow Kale Indoors or Outdoors

Kale is a hardy, cool-season leafy green vegetable that is rich in vitamins A and C, plus several minerals. Kale is part of the cabbage family and can easily be grown indoors or outdoors as long as growing temperatures stay on the cool side. This leafy green grows best outdoors in the spring and fall and can tolerate all fall frosts, but it can be grown year around indoors. Kale can be used raw in salads or cooked like collard or turnip greens.

Outdoor Planting

Select a planting location that receives at least six hours of sunlight per day. Improve the soil drainage and fertility by working in four inches of compost to the soil.

Plant kale anytime from early spring to early summer. When kale is planted late in the summer you can harvest it from fall until the ground freezes in winter. Light fall or spring frosts will not impact the texture of kale nor damage the plants, but it will give the leaves a slightly sweet flavor.

Create rows in prepared soil that are 8-12 inches apart. Plant seeds ¼ to ½ inch deep and lightly cover with soil. After about 2 weeks, thin the seedlings so they are spaced 8 to 12 inches apart.

After Care

Water the plants regularly. Add a 2 inch layer of mulch around spring and summer plantings to retain moisture and prevent weed growth. Mulch the soil heavily around each plant after the first hard freeze; the plants may continue to produce edible leaves throughout the winter.

Indoor Planting

Start with the same-sized pots so all plants will be an equal distance away from the light source. Fill pots with good quality potting soil, then moisten the soil and scatter kale seeds on top. Lightly cover the seeds with soil, place under grow light for 12-14 hours per day and keep soil moist at all times. A non-heat producing grow light, like an LED, is best for kale since it prefers temperatures between 50-70 degrees. Use a closed room or grow tent to maintain a steady cool temperature.

After germination, thin plants to 8-12 inches apart and continue to keep soil damp and grow light on.

Plant kale seeds indoors every 2 weeks for a continual fresh harvest of this nutritious vegetable.

Harvest Time

Kale is ready to harvest when the leaves are about the size of your hand.

Pick about one fistful of leaves per harvest. Avoid picking the terminal bud (found at the top center of the plant) so the plant will remain productive.