Is there a vegetable that offers a better return on investment than kale? This stately green is incredibly nutritious, versatile in the kitchen, cold-hardy, and surprisingly space-efficient. There’s really no reason a motivated gardener shouldn’t have kale on their planting list.
A member of the Brassica family, kale is closely related to broccoli, cauliflower, and cabbage. But unlike those crops, which are grown for flower buds or heads, kale is harvested for its leaves—making it a highly efficient crop, especially for space-conscious or small-space gardeners. Once established, kale is one of the easiest and most rewarding vegetables you can grow.
When and Where to Grow Kale
Kale thrives in nearly every climate zone. In colder areas, you can even overwinter your crop for an early spring harvest. While kale does best in full sun, partial shade is ideal in hot climates to prevent the leaves from becoming tough and bitter.
How to Plant Kale
Kale is a versatile crop that grows well in garden beds, raised beds, containers, and even flower gardens as an ornamental edible. The wide range of leaf colors makes it a stunning and functional addition to any landscape.
Kale Seed Germination Basics
Kale seeds are hardy and can germinate in cool soil, though optimal germination occurs at temperatures above 70°F. Use a row cover to warm the soil and maintain the minimum 45°F needed for successful germination. Properly stored, kale seeds remain viable for up to five years.
Starting Kale Seeds Indoors
For an early spring harvest, start seeds indoors 4–6 weeks before your last frost date. Sow seeds in compost-rich soil about ½ inch deep, and keep them consistently moist. Once the seedlings sprout, give them plenty of light.
Preparing Your Kale Bed
Choose a sunny spot and amend the soil with organic compost. Kale prefers a soil pH between 6.0 and 7.0. For extra nutrient support, plant a nitrogen-fixing cover crop (like peas or beans) before growing kale, then till it into the soil.
Transplanting Outdoors
Move your kale outdoors 1–2 weeks before your last expected frost, once seedlings have at least 3–4 true leaves. Harden them off first by gradually exposing them to outdoor conditions over a week. Space plants 12–15 inches apart in rows 18–24 inches apart. With protection from strong winds, your kale will establish quickly and grow fast.
Growing Kale in Containers
Thanks to its compact nature, kale is ideal for container gardening. Use pots with at least 6 inches of growing space. In hot climates, move containers between sun and shade as needed. Indoors, place near a sunny window or under grow lights for best results.
Direct Seeding Kale
You can direct sow kale seeds about a month before your last frost date or as soon as the soil can be worked. Plant seeds ¼ inch deep, spacing them 6–8 inches apart. Once seedlings are 4 inches tall, thin them to 18 inches apart. Don’t toss the thinnings—they’re delicious in salads!
For a fall harvest, sow seeds 6–8 weeks before your first expected frost.
Watering & Mulching Tips
Kale needs about 1 inch of water per week, especially during peak summer heat. As temperatures cool, reduce watering unless the leaves begin to droop.
Fertilize monthly with compost tea or fish emulsion for lush, healthy growth. Mulching under each plant helps keep soil moist, prevents weed growth, and stops rain from splashing dirt onto leaves. Use biodegradable mulch like grass clippings or shredded leaves.
Companion Planting & Crop Rotation
Because kale is a Brassica, avoid planting it where other Brassicas (like cabbage, broccoli, or cauliflower) were recently grown to reduce disease risk.
Good companions for kale include:
- Onions
- Beets
- Celery
- Herbs (like dill and chamomile)
Avoid planting kale near:
- Beans
- Grapes
- Strawberries
Common Kale Pests and Diseases
Kale is relatively pest-resistant, but keep an eye out for:
- Cabbage worms (larvae of the white cabbage butterfly): These chew holes in leaves. Pick them off by hand or use Bt spray.
- Flea beetles and aphids can also become an issue, especially in spring.
Preventative tips:
- Use floating row covers early in the season.
- Rotate crops annually.
- Inspect plants regularly and remove pests promptly.
Harvesting Kale
You can begin harvesting kale about a month after planting or once the leaves are large enough to eat. Look for deep color and firm texture. Younger leaves are perfect for salads; larger, mature ones are best for sautéing or soups.
To harvest: bend the leaf away from the main stalk until it snaps off. Regular harvesting encourages continuous new growth.
Bonus tip: A few frosts actually improve kale’s flavor by concentrating the sugars—making the leaves taste sweeter.
Storing Kale
Fresh kale lasts about 2 weeks in the refrigerator. For long-term storage:
- Freeze: Blanch and freeze leaves for soups and stews.
- Dehydrate: Make your own kale chips for a crunchy snack.
Saving Kale Seeds
Kale is a biennial, meaning it flowers in its second year. To save seeds:
- Let second-year plants flower and form seed pods.
- Allow pods to dry on the plant.
- Collect and dry pods indoors for a week.
- Shatter the pods and store the seeds in a cool, dry place. They’ll stay viable for 4–5 years.
To avoid cross-pollination, isolate your kale plants from other Brassica species.
Popular Kale Varieties
- Red Russian: Light purple stems with tender gray-green leaves. Great raw in salads.
- Lacinato (Dinosaur Kale): Dark, bumpy leaves. Hardy and perfect for winter gardens.
- Winterbor: Curly, deep green leaves. Excellent for kale chips.
Final Tips for Growing Organic Kale
- Spring kale often becomes insect-prone by mid-summer. Many gardeners compost it in July and start a fresh fall crop.
- For consistent supply, plan for 3–4 kale plants per person in your household.
- Harvest frequently to keep plants producing and avoid woody or bitter leaves.
Kale truly earns its reputation as a garden MVP—nutritious, versatile, and forgiving to grow. Whether you’re gardening in raised beds or patio containers, it’s one crop that’s worth your time, space, and effort.