Fast, cool-season Asian greens do best in New York: tatsoi, mizuna, komatsuna, mustard greens and compact bok choy. They finish in the cool weeks of spring and again from late summer into November, and they struggle in midsummer heat. Heading napa cabbage and heat-lovers like water spinach are harder bets. The right pick shifts a lot between the city and the Adirondacks.
The short answer for New York
Choose by type. Hardy leafy greens (tatsoi, mizuna, komatsuna, the mustards) are the safest group because they grow quickly, shrug off light frost and can be cut young. Bok choy comes next, with small and baby types working best. Napa cabbage is a fall crop. Heat-lovers sit at the bottom of the list.
The frost dates explain why. For New York City (the Central Park reference station, not the whole state), the last spring freeze at 32°F falls somewhere between March 23 and April 3. That range is the 30 to 70 percent probability band in the 1991-2020 normals for New York City. The first fall freeze falls between November 14 and November 27, on the same probability basis. Between those two windows lies a long stretch of cool weather that suits these crops well.
Which Asian greens suit spring sowing in New York?
Mizuna, tatsoi, komatsuna and baby bok choy go in as soon as the soil can be worked. Their seedlings tolerate the frosts that still arrive after the average last freeze date. Harvest them young, as baby leaves or small heads, before the lengthening days of late spring push them to bolt. Choy sum and gai lan also work in spring, with a little more tolerance for warmth.
Which Asian greens suit fall sowing in New York?
Fall is the better season for almost all of them. Seeds sown in late summer germinate in warm soil, then grow into cooling nights, which sweetens the leaves and keeps bolting away. Full-size bok choy and napa cabbage belong here, since napa needs time to form a head in cool weather. The dates for each type are laid out in When to Sow Asian Greens in New York, and the broader overview sits in Growing Asian Greens in New York.
What will not work here
Winter is the first wall. The mean daily minimum of the coldest month at the city reference station is 27.9°F. That is an average, so many nights run colder, and upstate they run much colder still. Unprotected greens in an open bed will not overwinter. Tatsoi and mizuna are the toughest of the group, and under a cold frame or a low tunnel they can keep producing well into winter in the milder parts of the state. Bok choy and napa will not.
Why does bok choy bolt in a New York summer?
Long days and warm nights tell cool-season greens to flower. Bok choy, napa cabbage and mustard sown in late spring will run to seed before they make anything worth eating. The city’s last spring freeze arrives between March 23 and April 3, so there is room to sow early. A crop sown in May instead of March gets squeezed into the weeks when bolting is most likely. Full-size napa sown in spring is the classic failure: it needs weeks of cool weather to wrap a head, and spring does not last long enough.
Which Asian greens struggle with humid summers and a short season?
Heat-lovers like water spinach need warm soil and warm nights for steady growth. Sown outdoors early, the seed sits in cold ground and rots. Sown on time, the plant barely gets going before fall. Only a hot, sheltered spot or a container gives it a fair chance.
Summer humidity is the other problem. Dense plantings of bok choy or napa stay damp, and that invites fungal leaf spots and slugs. Flea beetles, which pepper mustard-family leaves with small holes, are worst in warm, dry spells. Give plants room, water in the morning, and cover young plantings with fine row cover when beetles appear.
One more trap is treating the average last freeze date as a guarantee. At the early end of the band, a freeze after that date is still possible. Seedlings of hardy greens can take a light frost, but a hard freeze on tender young bok choy will set it back.
What changes across New York
New York is not one garden. The USDA Plant Hardiness Zone Map (2023 edition, built on 1991-2020 normals) runs from zone 3b to 7b across the state. That system measures a single thing, the average annual extreme minimum temperature, so it describes how cold the worst winter nights get. A spread of that size means there is no single answer for the whole state. The city sits near the warm end of the range, and the Adirondacks sit near the cold end.
Dates from the Central Park station should be read as New York City dates. Dense urban sites hold heat, so upstate and Adirondack gardens frost earlier in fall and later in spring. A gardener in the north or at altitude should sow spring crops later than the city dates suggest, and start fall crops earlier so they size up before hard frost arrives. The fastest types (mizuna, tatsoi, baby bok choy, komatsuna) matter most there, and napa cabbage becomes a gamble that needs an early start and a row cover on cold nights.
Gardeners near the coast and in the city can stretch the season at both ends. They can sow a little earlier in spring, keep cutting under cover, and treat a cold frame as a way to extend the harvest.
To find your own zone, look up your ZIP code on the USDA Plant Hardiness Zone Map. Zone numbers describe winter cold, though, so check your local frost dates as well.
Where to check this for your own county
Your county office of Cornell Cooperative Extension is the best next stop. Local offices run through the land-grant system are staffed by people who know the local soil, frost pockets and pests.
Two things are worth looking for there. The first is a local planting calendar. A county calendar is built on local frost records, so its spring and fall windows will fit your garden more closely than a statewide range or a city station. The second is any list of varieties trialled in your county. Trials show which bok choy resists bolting, which napa forms a head before the freeze, and which mustards the flea beetles leave alone.
Ask the office about local pest timing too. Pests that attack Asian greens in particular have seasons that differ between Long Island and the Finger Lakes, and a county horticulture educator can tell you when to cover.
A county recommendation beats a state one. Statewide advice like the guidance above has to cover a range from zone 3b to 7b, which makes it a good starting frame and a poor final answer. Where the two disagree, go with the county.
Checking this against your own garden
Your own observations outrank any date in print. Three are easy to make without equipment.
- Soil warmth by feel. Push your hand a few inches into the bed in early spring. If the soil crumbles instead of clumping into a wet ball, and your hand does not ache after a minute, it is ready for hardy greens. A bed that stays cold and soggy later than the neighbor’s is slow, so sow later there.
- The first true leaves. Sow a short test row. The first true leaves, the ones after the round seed leaves, show how fast things are moving. If they appear quickly and plants stay compact, your timing is right. If the plants stretch and flower early, you have sown too late or the spot is too warm.
- Which plants the first frost hits. In fall, watch tender plants like basil or zinnias. If they blacken in a low corner of the yard while the rest of the garden is untouched, you have a frost pocket. Put fall greens higher or closer to a wall and cover the low spots first.
Keep notes on the date each of these happens. After a season or two, those notes will be more accurate for your yard than any regional average.
Common questions
Which Asian green is easiest for a first-time New York gardener?
Mizuna and tatsoi are the easiest. They germinate readily, grow fast, tolerate frost and forgive late or early sowing better than bok choy or napa. Cut them as baby leaves when they are a few inches tall.
Can Asian greens survive a New York winter outdoors?
Unprotected, mostly no. The coldest month averages a nightly low of 27.9°F at the city reference station, and colder spells come often. Tatsoi and mizuna can hold on under a cold frame or low tunnel in milder areas, but bok choy and napa will not.
Is bok choy or napa cabbage the better choice for fall?
Bok choy is the safer one. It can be cut at any size, so a cold snap does not ruin the crop. Napa needs enough cool weeks to form a full head, so it must be sown early enough in late summer to finish before the freeze, which falls between November 14 and November 27 at the city reference station.
Do I sow earlier or later if I garden upstate?
Spring sowing starts later, because frost lingers longer than in the city. Fall sowing starts earlier, because the first freeze comes sooner. Your county Cooperative Extension office can give you the local dates.