Safe to Plant

Vegetable · Brassicaceae

When to plant kale

Hardier than any other brassica and better after frost than before it.

Start seed indoors

6 weeks before

Counted from your last spring frost.

Plant out

2 weeks before

Counted from your last spring frost.

Sow direct

2 weeks before

Counted from your last spring frost.

Those weeks become real dates once you name a place.

Timing, in frost-relative terms

Seed packets rarely give calendar dates, because a date that suits one latitude is wrong at another. They give offsets from the last spring frost instead, and those offsets are what make kale plantable anywhere.

  • Start seed indoors 6 weeks before the last frost.
  • Plant out 2 weeks before the last frost.
  • Sow direct 2 weeks before the last frost.
  • Expect 55–75 days to maturity, counted from sowing.
  • Can also be sown in late summer for an autumn crop or to overwinter.

Getting the timing right

Spring sowings feed you through summer; the sowing made twelve weeks before first frost is the one that carries you through winter.

Frost tolerance

Survives -12C and sweetens markedly below freezing as starches convert to sugars. Frost is a feature of this crop, not a threat.

Classified as very-hardy, with damage expected below -12°C (10.4°F).