I've grown both and have yet to get them very large before they bolted. Probably, as with many bolt prone greens, it would help to plant them in mid summer for a fall crop. That way they mature as weather gets cooler. That's just my hunch. Here is advice from gardentrekker (Sun, Sep 23, 07)on that subject: "The secret to tender and healthy yu choy is to have them grow very fast. The way I do it is of course, as I mentioned, rich soil with lots of humus. Sprinkle seeds sparsely (5 or so inches if you don't want to transplant, or 2 or 3 inches apart if you intend to) on top of the soil. Sprinkle fine cut grass (if you have it), and water very gently twice a day. The seeds will germinate as quickly as four or five days if conditions are good. At this stage, it is okay to let them be in partial sun, in fact it is better (use burlap tenting if the weather is very hot and dry). If your soil prep is correct, the primary leaves will look large and healthy (you will see some that are smaller), and within a few days the secondary leaves will appear. Transplant (if you wish) when they are around three inches tall into a raised bed. The best day to transplant is on an overcast or somewhat rainy day, or else in the evening when there is no more sun. (My transplanted ones tend to be more robust). Water twice a day, morning and late afternoon, and fertilize with a high nitrogen mix ( I make a compost tea with manure). The best days to fertilize is on rainy days (it seems to me) or in the late afternoon. When ready to harvest, cut the center stalk and allow the lower nodes to sprout side stalks. Water immediately after you cut any. If they weather is too hot or too cold, they will start to blossom. Once they start, even if you harvest the center stalk, the sides would start to blossom also. Otherwise, you will have the most tender luscious greens for your table." I don't recall any pest problems. Jim

Jay, I harvest Choy Sum the same way Chinese Broccoli (Gai Lan or Kai Lan) is harvested. So far I have picked twice from the plant sown on Ang.7 and the little stem for a 3rd picking is already showing. The 1st harvest gives me a beautiful rosette with a center stem surrounded with leaves and maybe a center flower head. The 2nd harvest is exactly the same rosette form and as beautiful and tasty as the 1st. The rosette is very showy in cooking presentation. Choy Sum in Chinese means "Center of the vegetable" and is often eaten in the rosette form so people can enjoy the center (a feast to the eyes and the taste buds). Unlike many leafy vegetables, Choy Sum center flowers taste great and flowering does not change the taste of the leaves. Too bad I didn't take any pictures before eating them. I was told that a Gai Lan plant can keep producing side shoots for up to 3-5 pickings. But the side shoots gets smaller after each time, and finally becomes impractical. I have not noticed significant size changes yet, but will not be surprised if it does get smaller. Come to think of it, maybe it'll be better to grow the regular Choy Sum so the 4th or 5th picking will not be too diminutive?

Your assessments are correct. Kai lan/gai lan/Brassica oleracea is in the broccoli family so treat it as such. So they are a cool weather crop so plant for the fall or early spring. Yu Choy is also in the Brassica family but will not tolerate temps that are too cold. I wouldn't necessarily grow it in full sun in 90-100 degree weather either - at least not without afternoon shade. Yes, different varieties will do better in different environments. But as a general rule, both should do well in spring and fall. Check with your state's Extension Service. Each county should have it's own Cooperative Extension Office which provides free publications and information for the asking. They can also tell you the average last frost date for your area and ideal planting times for specific crops and varieties in your area. (Broccoli, for instance.) The following two images are excerpts from the Vegetable Planting and Planning Calendar for Missouri (download the pdf complete with spring and fall planting dates, how much to plant per person, etc. Just call up the office in your county. Look under the "Government" section (usually blue pages) of your phone book under "Extension". They will have valuable vegetable/gardening tables available specifically for your area from data they've collected from growing those crops in your state. Experiment, keep a journal, let us know how it goes. Violet

This is such a confusing old thread that I can understand how it just generates more questions and how there is probably a reluctance by some to step in with any answers. Let me just say what I do: I grow bok choy each year and try to have it for as much of the growing season as possible. That means I sow seed and resow seed. I move plants around first out of the greenhouse and also where the bok choy seedlings are a little too crowded in a seed bed. Bok choy seems to bolt fairly easily. I think it bolts when it is stressed by too much cold just as it does when conditions are hot and dry. There is probably only a fairly narrow window when its growth is optimum but this doesn't mean it is unusable all the rest of the season! As far as treating it as a cut-and-come-again when harvesting leaves: I've never done that and I've grown bok choy for a good 20 years. The flower buds are a different story, however. Sure, if it would take a half dozen of your plants to make a fork-full and the plants are already bolting - you haven't got much going in the bok choy patch. But, if your baby bok choy is as big around as your wrist and it starts to send a flower stalk up - get that and bring it into the kitchen! Even if the little yellow flowers have started to open -- to me, that flower stalk is the sweetest part of the plant and is often, plenty tender! It would be a shame, to my way of thinking, to throw that plant in the compost. The lower leaves, however, are probably too tough to enjoy. But, if you've got 1 good-sized flower stalk, chances are, you will get a couple more off that plant in a few days. Of course, they will be smaller. Yes, tender little bok choy leaves are great. And, if they have begun to bolt - their season is coming to an end. All the more reason to have seed going in the ground just about every week. You may have to take a month or 2 off from sowing bok choy seed but get back to it as the temperatures begin to drop in late summer. Bok choy makes a fine fall crop here and probably where you garden, also. Steve