It is day length that triggers bolting. If planted after the summer solstice when days are getting shorter, they will not bolt. Same with turnips. The old saying for planting turnips is 25th of July wet or dry.Yes, I start the seeds indoors, and I've planted them outside after only a couple weeks. They handle cool/cold weather really well too. I would try direct seeding but with slugs and earwigs in the garden I think setting out started plants gives them a better chance of survival.
It's actually Baby Choi I'm growing, and they're some of the fastest growing things I've planted in the garden. But they're quick to bolt when the temperature gets warm outside, or maybe it has to do with the length of daylight.
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