Kale is one of the hardiest and longest-producing vegetables in the garden. A few plants give leaves for months, from spring through summer and well into winter, and frost makes them sweeter. It is a cool-season member of the cabbage family that needs rich soil and steady water. This page covers when to plant, how to space it, how to protect it from pests and how to harvest so it keeps producing.
Kale at a glance
| Type | Vegetable |
|---|---|
| Season | Cool-season |
| Sun | Full sun to part shade |
| Plant spacing | 18 in |
| Row spacing | 24 in |
| Per square foot | 1 |
| Seed depth | ½ in |
| Days to maturity | 50–65 from seed |
| How to start | Direct sow or indoors 4–6 weeks before last frost |
| Water | 1 in per week |
These are the same numbers our plant spacing, square foot and harvest date calculators use. See every crop in the plant database.
When to plant kale
Kale tolerates frost and grows best in cool weather. For a spring crop, start seeds indoors 4 to 6 weeks before your last spring frost and plant out 2 to 4 weeks before it, or sow directly once the soil can be worked. For a fall and winter crop, which is often the best, sow in midsummer, about 10 to 12 weeks before your first fall frost. Mature kale survives temperatures into the low 20s°F and lower.
Find your dates with the frost dates by ZIP code tool and the planting calendar.
How to plant kale
- Choose sun or part shade. Six hours of sun is ideal; kale tolerates some shade, especially in hot summers.
- Plant in rich soil. Kale is a heavy feeder. Mix in compost before planting.
- Sow 1/2 inch deep. Sow a few seeds per spot and thin to the spacing in the table above, or set transplants at the same depth they grew.
- Rotate. Do not plant kale where cabbage-family crops grew in the past 2 to 3 years. The crop rotation checker helps plan this.
- Cover early. Lightweight row cover from planting keeps cabbage worms and flea beetles off.
Caring for kale
Water about an inch a week and keep the soil evenly moist; dry, stressed kale turns tough and bitter. Mulch helps keep the roots cool in summer. The garden watering calculator turns the weekly amount into gallons.
Side-dress with compost or a nitrogen-rich fertilizer about a month after planting and again midseason for steady leaf growth. In cold regions, mulch around plants in late fall and use row cover to extend your harvest into winter.
Companion plants
| Grow nearby | Onions, garlic, dill, nasturtiums, beets, celery, potatoes |
|---|---|
| Keep apart | Strawberries; other cabbage-family crops in the same spot as last year |
Strong-scented onions and garlic help confuse cabbage pests, and dill attracts the wasps that prey on cabbage worms. Nasturtiums act as a trap crop for aphids. Check other pairings with the companion plant finder.
Common problems
| Problem | What you see | What to do |
|---|---|---|
| Cabbage worms and loopers | Green caterpillars and ragged holes in leaves; small white butterflies around plants | Use row cover from planting, hand-pick caterpillars and spray Bt if needed. See the pest identifier. |
| Aphids | Gray, waxy clusters under leaves and in new growth | Spray off with a strong stream of water and encourage ladybugs. |
| Flea beetles | Many tiny holes in young leaves | Use row cover. Older plants outgrow the damage. |
| Harlequin bugs | Black and orange shield-shaped bugs; leaves with white blotches | Hand-pick bugs and crush egg clusters, which look like tiny barrels. |
| Tough, bitter leaves | Leaves are leathery and sharp-tasting | Heat and drought stress. Keep watered, pick young leaves and grow the main crop in fall. |
Not sure what you are looking at? The plant problem identifier ranks likely causes from the symptoms you see.
When and how to harvest
Begin picking when plants are 8 to 10 inches tall. Take the lower, outer leaves first, cutting or snapping them off at the stem, and leave the central bud and at least 4 or 5 leaves at the top. The plant keeps making new leaves from the center for months. Young leaves are tender for salads; larger leaves are best cooked.
Kale tastes sweeter after a few frosts, because cold makes the plant store sugar. Keep picking through fall and into winter. Store unwashed leaves in a bag in the fridge for up to a week. Use the harvest date calculator to estimate when you can start picking.
Plan your kale
- Plant spacing calculator: how many plants fit your bed
- Planting calendar: sowing and transplant dates for your frost dates
- Frost dates by ZIP code: your last spring and first fall frost
- Harvest date calculator: when your crop will be ready
Frequently asked questions
How far apart should I plant kale?
Space kale 18 inches apart in rows 24 inches apart. In a square foot garden, plant 1 per square foot.
How deep do I plant kale seeds?
Sow seeds ½ inch deep.
How long does kale take to grow?
Most varieties are ready 50–65 days from seed. Check the seed packet, because early and late varieties differ.
How much water does kale need?
About 1 inch of water a week, from rain and watering combined. Keep the soil evenly moist; dry soil makes leaves tough and bitter.
How do I harvest kale so it keeps growing?
Pick the lower, outer leaves and leave the central bud and top leaves. The plant keeps producing new leaves for months.
Can kale survive winter?
Kale tolerates hard frosts, and mature plants survive into the low 20s degrees F or colder, especially with mulch and row cover. Frost makes the leaves sweeter.