Kale - Growing Kale in the Home Vegetable Garden

Overview: Kale is a leafy vegetable that is usually grouped into the “Cooking Greens” category with collards, mustard and Swiss chard. The leaves can be curly and quite ornamental, but become too tough to eat fresh, as they mature. Kale is a member of the cabbage family and is susceptible to many of the same pests.

Latin Name: Brassica oleracea

Common Name(s): Kale, Borecole

Zones: Annual Crop

Size: Varies with variety. Most are about 12 - 36" spread, 12 - 24" height

Exposure: Full sun

Days to Harvest: Approximately 2 months, depending on temperature

Harvesting: You can harvest very young leaves to use fresh in salads or allow plants to mature and use as a cooked green. Harvest older leaves by removing the larger, outer leaves and allowing the center of the plant to continue producing. Kale will be good throughout the summer months, but especially good after a frost.

If you need to store picked kale, place it in the refrigerator and keep it moist but not sealed. It can retain it’s crispness this way for a week or two.

Pests: Kale is relatively pest free, but can be susceptible to : black rot and club root as well as aphids, cabbage loopers, cabbageworm, cutworms and flea beetles. The best defense is to provide good growing conditions and keep the plants healthy.

Suggested Varieties: ‘Vates’ derived from ‘Dwarf Blue Curled Scotch’ very weather tolerant (heat & cold) and tasty
‘Hanover Salad’ Fast grower and early producer. Nice for fresh use.
‘Lacinato’ An heirloom kale from Tuscany, with thin puckered leaves. Hardy enough to harvest after a snowfall.

Cultural Notes: Kale prefers cool temperatures and will be sweetened by a touch of frost. Optimal soil temperature is 60 - 65 degrees F. Hot weather turns kale bitter.

Kale plants like to grow in a rich soil, high in organic matter and slightly acidic (5.5 - 6.5 pH). You’re growing it for the foliage, so a high nitrogen content is good.

Kale can be direct seeded in the garden or started indoors and set out as transplants. Start plants indoors about 6 weeks before your last expected frost date. Kale seeds germinate quickly in warm soil and should be up within 5 - 8 days.

Transplant seedlings after danger of frost. Set plants out with about 16" spacing between plants. This gives them room to spread out and still allows for air circulation.

You can direct seed in cold climates, in the spring, as soon as the soil can be worked and the soil temperature is at least 45 degrees F. Kale matures quickly, in about 2 months or less, so if you prefer you can start your plants later or even plant multiple crops in succession. In warm climates, kale can be direct seeded in late summer / early fall, as well as in the spring. A winter crop of kale in warmer climates can be much sweeter than a summer crop.

Cover seeds with about ½ inch of soil and don’t allow the seeds to dry out before germinating. Plants will grow more slowly outdoors than indoors under lights.

Maintenance: Keep your kale plants well watered.. Along with cool temperatures, moist soil helps keep kale leaves sweet and crisp, rather than tough and bitter. Side dressing throughout the growing season with compost or feeding with fish emulsion will keep your kale growing. Mulch is important to keep the ground cool.