One Kilo SB
Napa Cabbage in the US

Napa cabbage is a cool-season crop, so you’ll want to get it going in spring or for a fall harvest, checking your local last and first frost dates. You can sow seeds direct into the ground, about half an inch (1 cm) deep, spaced 12 to 18 inches (30-45 cm) apart. Or, if you’re like me and like to get a head start, sow them indoors in pots a few weeks before your last frost, then transplant them out once they’re big enough. For a steady supply, sow a few seeds every couple of weeks, that's what we call succession planting.

If you've sown direct and got too many seedlings, thin them out to give each plant enough room, about 12 to 18 inches (30-45 cm) between them. For those started indoors, they’ll need a bit of hardening off before going out. That means gradually getting them used to the cooler air and sun for about a week. Plant them out when the danger of hard frost has passed, ensuring they've got good space to form those nice, tight heads.