When to plant kale by city
Start kale indoors 6–8 weeks before your last frost, plant them out 2–4 weeks before your last frost, or sow seed outdoors 2–4 weeks before your last frost. For a fall crop, sow 6–10 weeks before your first fall frost. Here is what that means for 2027 in cities across the US, using each city’s average frost dates (NOAA 1991–2020). Pick the city with the climate most like yours, or enter your ZIP code above.
| City | Last frost | Start indoors | Plant out | Sow outdoors | Fall crop |
|---|---|---|---|---|---|
| Seattle, WA (9a) | Mar 13 | Jan 16–30 | Feb 13–27 | Feb 13–27 | Sep 8 – Oct 6 |
| Portland, OR (8b) | Feb 25 | Dec 31 – Jan 14 | Jan 28 – Feb 11 | Jan 28 – Feb 11 | Sep 22 – Oct 20 |
| Sacramento, CA (9b) | Jan 12 | Nov 17 – Dec 1 | Dec 15–29 | Dec 15–29 | Oct 7 – Nov 4 |
| Phoenix, AZ (10a) | Jan 5 | Nov 10–24 | Dec 8–22 | Dec 8–22 | Oct 25 – Nov 22 |
| Salt Lake City, UT (7b) | Mar 31 | Feb 3–17 | Mar 3–17 | Mar 3–17 | Aug 30 – Sep 27 |
| Denver, CO (6a) | Apr 30 | Mar 5–19 | Apr 2–16 | Apr 2–16 | Aug 3–31 |
| Dallas, TX (8b) | Mar 2 | Jan 5–19 | Feb 2–16 | Feb 2–16 | Sep 20 – Oct 18 |
| Minneapolis, MN (5a) | Apr 23 | Feb 26 – Mar 12 | Mar 26 – Apr 9 | Mar 26 – Apr 9 | Aug 7 – Sep 4 |
| Kansas City, MO (6b) | Apr 4 | Feb 7–21 | Mar 7–21 | Mar 7–21 | Aug 24 – Sep 21 |
| Chicago, IL (6b) | Apr 10 | Feb 13–27 | Mar 13–27 | Mar 13–27 | Aug 27 – Sep 24 |
| Columbus, OH (6b) | Apr 20 | Feb 23 – Mar 9 | Mar 23 – Apr 6 | Mar 23 – Apr 6 | Aug 15 – Sep 12 |
| Nashville, TN (7b) | Apr 1 | Feb 4–18 | Mar 4–18 | Mar 4–18 | Aug 22 – Sep 19 |
| Atlanta, GA (8a) | Mar 24 | Jan 27 – Feb 10 | Feb 24 – Mar 10 | Feb 24 – Mar 10 | Aug 30 – Sep 27 |
| Raleigh, NC (8a) | Mar 28 | Jan 31 – Feb 14 | Feb 28 – Mar 14 | Feb 28 – Mar 14 | Aug 30 – Sep 27 |
| Philadelphia, PA (7b) | Mar 30 | Feb 2–16 | Mar 2–16 | Mar 2–16 | Sep 8 – Oct 6 |
| Boston, MA (7a) | Apr 4 | Feb 7–21 | Mar 7–21 | Mar 7–21 | Aug 31 – Sep 28 |
In frost-free parts of Florida, southern California and the Gulf Coast, timing is about heat instead: grow kale from fall through winter.
Kale spacing
In a square-foot bed, plant 1 per square foot. In traditional rows, space plants about 18 inches apart with 24 inches between rows.
Frost sweetens it. Pick outer leaves and it produces for months.
How to grow kale
Kale is one of the easiest and most productive greens. It tolerates cold better than almost any vegetable, frost sweetens the leaves, and plants picked a few leaves at a time keep producing for months. It suits beginners and anyone who wants greens from spring into winter.
Sun and soil
Full sun to part shade. Well-drained, fertile soil high in organic matter with a pH of 6.0–7.5. Kale survives drought, but leaves get tough and strong-flavored without regular water, about 1–1½ inches a week.
Planting
- Direct-sow ¼–½ inch deep 2–4 weeks before the last spring frost, when soil is at least 45°F.
- Or start seeds indoors 6–8 weeks before the last frost and transplant 2–4 weeks before it.
- Thin or space plants 18 inches apart in rows 24 inches apart. Eat the thinnings.
- For fall and winter greens, sow or transplant 6–10 weeks before the first fall frost.
Care
- Mulch with 2–3 inches of straw to keep roots cool and moist.
- Side-dress with nitrogen about 4 weeks after planting for tender, dark leaves.
- Keep row cover over young plants to stop flea beetles and cabbage moths.
- Growth slows above about 75°F; mature plants pick up again when fall arrives.
Harvest
Start picking when leaves are about the size of your hand. Take the lower, outer leaves and leave the center bud growing. Baby leaves for salad are ready 20–30 days after sowing. Leaves taste sweeter after a few frosts.
Common problems
- Cabbage aphids: Gray, waxy clusters on leaf undersides and new growth. Spray off with water, use insecticidal soap, and remove badly infested leaves.
- Cabbageworms and loopers: Row cover keeps moths off; Bt and hand-picking control caterpillars that get through.
- Flea beetles: Shot holes in seedling leaves. Cover seedlings from sowing; older plants outgrow the damage.
- Harlequin bugs: Black-and-orange bugs common in the South. Hand-pick adults and crush their barrel-shaped egg clusters.
Varieties to try
- 'Winterbor' — curly, blue-green, very cold hardy
- 'Red Russian' — flat, purple-veined leaves, tender
- 'Lacinato' (also sold as 'Toscano') — dark, puckered dinosaur kale
- 'Dwarf Siberian' — compact, frilly, very cold tolerant
Crop rotation
Kale belong to the cabbage family (Brassicaceae). Clubroot and cabbage pests build up in the soil. Rotate for at least 3 years. Relatives that count as the same family for rotation: broccoli, cauliflower, cabbage, brussels sprouts, radish, turnip, arugula, bok choy, kohlrabi.
Frequently asked questions
When should I plant kale?
What grows well with kale?
What should not be planted with kale?
How far apart should I plant kale?
How long do kale take to grow?
Can kale handle frost?
Sources
- Frost dates: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020.
- Hardiness zones: 2023 USDA Plant Hardiness Zone Map, USDA-ARS and PRISM Climate Group, Oregon State University.
- Planting windows and spacing: Vegetable Planting Guide (GardenNotes #720), Colorado State University Extension, and other land-grant extension guides.
- Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023
- Brassica flea beetles, UMass Amherst Vegetable Program
- Trap Cropping, Washington State University Extension Master Gardener Program
- Trap cropping: a review of the state of the art, Sarkar et al., 2018 (open-access review)
- Kale — NC State Extension
- Kale in the Garden — Utah State University Extension