Soil Preparation:

Kale prefers fertile, well-drained soil rich in organic matter for best growth. Most soils in Utah are suitable for kale production. Before planting, incorporate up to 2-4 inches of well composted organic matter and apply 4-6 cups of all-purpose fertilizer (16-16-8 or 10-10-10) per 100 square feet.

More Information on Soil Preparation

Planting:

Kale can be grown from seed or transplants.

• Kale grows best when temperatures do not exceed 75°F. Mature plants are extremely hardy and can withstand very cold temperatures without damage.
• Seeds should be planted ¼-¾ inch deep and thinned when plants have 3-4 true leaves.
• Seeded or transplanted kale should be spaced 12-18 inches between plants in the row with rows 2 feet apart.
• Transplants may be planted 2-3 weeks before the last frost-free date. Start seeds indoors 5-6 weeks before planting. Transplants should have 4-6 true leaves.
• For fall-maturing kale, select early maturing cultivars and plant 50 days before the anticipated maturity date, about 2-3 weeks after the first fall frost.

View Freeze Dates

Irrigation:

Water kale deeply and infrequently while trying to maintain even soil moisture. About 1-2 inches of water are required per week. Use drip irrigation if possible to conserve water. Applying mulch around the plant also helps conserve soil moisture and reduce weed growth. Moisture fluctuations will cause leaves to become tough and develop off flavors.

More Irrigation Information

Fertilization:

Apply 1/2 cup per 10 feet of row of a nitrogen-based fertilizer (21-0-0) 4 weeks after transplanting or thinning to encourage rapid plant growth. Place the fertilizer 6 inches to the side of the plant and irrigate it into the soil.

Fertilizing For a Successful Garden

Harvest:

Kale should be harvested when the leaves reach full size. Older leaves are generally stripped off the plants first allowing the young leaves to continue to grow. Frosts help improve the flavor of the fall planted crop. Kale can be stored for 2-3 weeks at 32°F and 95% relative humidity. Many gardeners leave kale growing in the garden throughout the winter.

Problems:

Plastic and organic mulches effectively control weeds. Be sure to control weeds when plants are small and be careful not to damage roots when cultivating. Use insecticidal soaps, appropriate insecticides, or strong water stream to dislodge insects. Flea beetles are common pests of Kale. Control with appropriate insecticides at seeding or after seedlings have emerged from the soil. 

References

For comprehensive information about growing kale, view/download:

• Kale in the Garden