Cabbage -- start indoors or direct sow?
Last year I grew nappa cabbage from seed and started them indoors sometime in late March to early April. I planted them outside in early May (last frost date is mid to late May here). This year I'll be growing them again, as well as "regular" cabbage. The non-Chinese cabbage is a "baby" variety that matures in 60 - 70 days.
My question is, was starting indoors necessary, or would these plants be able to handle being started outside in mid-spring? If I should stick with indoors, could I be starting them earlier and transplanting outdoors earlier? The reason I ask is because my nappa cabbage made a second head after I harvested the first one that was just fine in mid-December after we had days in the single digits. I know cabbage is cold-hardy, but the seed packet for the Chinese cabbage said it was not as cold hardy as regular cabbage. Surviving days in single digits is pretty darn cold hardy as far as I'm concerned (granted it had a layer of snow for insulation).
Thank you for any advice you have to offer!