Germination temperature: 40 F to 75 F
- May fail to germinate in warm soils.
Days to emergence: 6 to 10
- About 3 weeks at 50 F. About 5 days at 77 F, but germination drops to about 30 percent .
Seed can be saved 2 years.
As soon as you can work the soil in spring, sow seed ½ inch deep, 1
inch apart in rows 12 to 18 inches apart (or broadcast seed across a
wider area). Thin to 2- to 6-inch spacings. Closer spacings can stress
plants and cause them to go to seed (bolt) sooner.
planting is critical as dry soil, heat and lengthening days also
encourage bolting. Later plantings benefit from some light shade from
other crops. Follow early plantings with warm-season crops such as
tomatoes or beans.
Make succession plantings every week or two
until average last frost date. Use bolt-resistant varieties for later
plantings. Sow again in mid- to late summer for fall harvest. Seeds do
not germinate well in warm soil, so increase seeding rate to
compensate. Or pre-germinate seeds by placing them between sheets of
moist paper towel in a plastic bag and refrigerating until they sprout.
seedlings are difficult to transplant. For spring crops, start inside
only if your garden stays too wet in spring to allow direct seeding.
Start transplants inside about 3 to 6 weeks before last frost.
is shallow-rooted and requires consistent moisture to prevent bolting.
Water to keep soil moist. Mulch after plants are well established to
maintain moisture and suppress weeks. Use floating row covers to
prevent insect damage.
Do not overfertilize with nitrogen. Only
apply supplemental fertilizer if leaves are pale green. Add lime to
make sure pH is at least 6.0. You should suspect that your soil is too
acid if germination is poor and leaf tips and margins are yellow or
Plant in fall and mulch heavily for early spring crop.