key growing information

Growing Kale From Seed

How to grow kale from seed: soil and moisture, direct sowing and transplants, spring, fall and winter crops, pests, disease prevention and harvest.

By Hensley’s Seed Co. September 3, 2026

Kale - Key Growing Information

A view of a recent kale trial, a lacinato type growing in the background and a curly variety in the foreground.

SCIENTIFIC NAME:

Brassica oleracea

CULTURE:

Kale likes fertile, well-drained soil rich in organic matter, with a pH of 6.0–7.5, and steady moisture for the best leaves. For baby-leaf growing, see the Baby Leaf Brassica Greens culture.

DAYS TO MATURITY:

Counted from direct sowing; take off about 14 days for transplants.

DIRECT SEEDING:

Sow from early spring until roughly 3 months before your expected fall frost. For bunching, plant ½" deep in groups of 3–4 seeds every 12–18", rows 18–36" apart, and thin to one plant per group.

AVG. DIRECT SEEDING RATE:

For bunching: 1,000 seeds sow about 220'; 1 oz. about 1,110'; 1 lb. about 24,000'. TRANSPLANTING: Spring crop: choose varieties suited to warm-season growing. Sow ¼" deep, 2 seeds per cell in 50- to 72-cell plug flats, 3–4 seeds per inch in 20-row flats, or in an outdoor seedbed. Transplants are usually ready in 4–6 weeks. If you can, hold the soil above 75°F (24°C) until seedlings emerge, then drop the air temperature to around 60°F (16°C). Set plants 12–18" apart in rows 18–36" apart. Kale grows best between 55 and 75°F (13–24°C), ideally 60–70°F (16–21°C), but still produces well in summer warmth. Fall crop: start seedlings the same way in May and plant them out in June or July; where hard freezes come early in fall, sow early enough for plants to mature. Winter crop: in mild-winter areas where temperatures seldom drop below 32°F (0°C), kale can be grown through winter, with transplants set out from September through February.

INSECT PESTS:

Kale has fewer pest problems than cabbage and other brassicas. Cover plantings with row cover at planting to keep pests off, and use Bacillus thuringiensis (Bt) for cabbage worms and loopers.

DISEASE:

Prevention is the best approach: (1) rotate with non-brassica crops for several years, (2) use clean seed-starting mix and seedbeds, and (3) keep tools and fields clean. Select kale seed lots that tested negative for black rot (Xanthomonas campestris pv. campestris) and black leg (Phoma lingam).

HARVEST:

Start picking individual leaves about 2 months after planting. Kale is very hardy, and light frosts improve its eating quality into late fall. Plantings made in late summer can be carried through winter in cold frames or hoop houses, or in the open where winters are mild, and row covers stretch the picking season.

SIZED SEEDS:

Sized seed has been graded to a uniform size, which gives more precise spacing in mechanical seeders and a more even stand. Our kale seed is sized unless the product description says otherwise.

TRANSPLANTS:

About 6,400 transplants per oz.SEEDS/LB.: Avg. 124,000.

PACKET:

100 seeds per packet, enough for about 22'.