The best Asian greens for Vermont are the fast, cold-tolerant leaf types: mizuna, tatsoi, komatsuna, mustard greens and baby bok choy. They finish in cool weather, shrug off light frost and give you a harvest in a few weeks. Slow, heading types such as full-size napa cabbage are a riskier bet. They need careful timing to beat both summer heat and the first hard freeze.
The short answer for Vermont
Choose by type, and let the frost dates set the rule. At the Burlington reference station, the last spring freeze falls between April 30 and May 10, and the first fall freeze between October 3 and October 13. Those dates are the band where the chance of a 32°F freeze runs from 30 to 70 percent, so they mark a window of real uncertainty and not a fixed line. Burlington sits on Lake Champlain, the mildest corner of the state, so much of Vermont gets less room than that.
A season that short favors crops that mature in about a month or six weeks from sowing. Asian greens sown directly in the ground count their days from sowing, and the leafy types fit comfortably inside the spring and fall windows. The table sorts the main types by the traits that matter here.
| Type | Speed | Cold tolerance | Bolting in heat | Best use |
|---|---|---|---|---|
| Mizuna | Very fast | High | Moderate | Spring and fall, baby or full leaf |
| Tatsoi | Fast | Very high | Moderate | Fall, and late into the season under cover |
| Komatsuna | Fast | High | Low to moderate | Spring, summer and fall |
| Mustard greens | Fast | High | High | Early spring and fall |
| Baby bok choy | Fast | Moderate | High | Early spring and early fall |
| Full-size napa cabbage | Slow | Moderate | Very high | Fall only, sown in midsummer |
Which Asian greens suit spring sowing in Vermont?
Mizuna, komatsuna, mustards and small bok choy germinate in cool soil and grow quickly in the cool, lengthening days of April and May. Sown as soon as the ground is workable, they can be cut as baby leaves before the weather turns warm. Early sowings sometimes take a frost or two, and the hardy types handle that. Plan to finish the harvest by late June, because the longest days of the year push these plants toward flower stalks.
Which Asian greens suit fall sowing?
Fall is the better season for most of them. Seeds sown from midsummer on meet cooling nights, shortening days and fewer insects, which gives sweeter leaves and little bolting. Tatsoi comes into its own here. It forms a flat rosette that sits low and tolerates hard frosts, and it keeps producing after tender crops have blackened. The exact sowing dates depend on your location, and When to Sow Asian Greens in Vermont walks through them. For the wider picture of the crop in the state, see Growing Asian Greens in Vermont.
What will not work here
Full-size napa cabbage sown in spring will fail. It needs a long season to form a head, which puts maturity in the heat of July, and warm weather and long days send it to seed before the head fills. Sown in midsummer for fall, it can work, but the first freeze can arrive as early as October 3 at the mildest reference station and sooner in the hills. A head that is still loose when the freeze comes will not recover its sweetness.
Wintering greens outdoors without protection is the second dead end. The mean daily minimum of the coldest month at the Burlington reference station is 12.9°F. That is an average, so many nights run colder. Even tatsoi, the hardiest of the group, will not live through a month of those lows in an open bed. A low tunnel or cold frame can stretch the harvest later into the season, and sometimes beyond. Counting on plants to sit out January and wake up in March will mostly produce a bed of mush.
Early planting of tender seedlings is a third mistake. The last freeze can land as late as May 10 even on the lakeshore, and later in the mountains. A bok choy transplant set out in mid-April is exposed to a 30 to 70 percent chance of a freeze at some point afterward, depending on how the weather shapes up. Bok choy that gets a hard chill while young tends to bolt early. Direct-sowing hardy leaf types is safer, and a sheet of row cover costs little for the nights that dip below freezing.
A fourth failure is a June or early July sowing of mustards and bok choy. These bolt quickly in warm weather and long days, and flea beetles pepper the leaves with small holes. Flea beetles are worst in late spring and early summer. Row cover laid at sowing keeps them off, and it is a reliable tool.
What changes across Vermont
No single answer fits the state. The USDA Plant Hardiness Zone Map (2023 edition, built on 1991-2020 normals) places Vermont across zones 3b to 5b. That is a wide spread for such a small state. Zone 3b covers the coldest uplands and the Northeast Kingdom, and zone 5b reaches the warmest lowland pockets. The map is built on one variable, the average annual extreme minimum temperature, so it tells you about winter survival of perennials and little about how long your growing season is.
For annual greens, frost dates matter more than the zone number, and the Burlington dates run substantially longer than those in the Green Mountains and the Northeast Kingdom. A gardener in the north or at higher elevation should shift in three ways. First, sow spring crops later, because cold soil holds on longer. Second, count backward from the first fall frost and sow fall crops earlier, which can mean mid-July where the lakeshore gardener waits until early August. Third, lean even harder on the fastest, hardiest types and skip heading napa altogether.
Cold air also drains downhill and collects in hollows, so a garden at the bottom of a valley can freeze while the slope above stays clear. At altitude, a low tunnel or a cold frame turns a short season into a workable one. A lakeshore or valley gardener has more slack but loses little by using the same protection.
To see where your own place falls, use the USDA Plant Hardiness Zone Map and enter your ZIP code. The result is a starting point and not a verdict on what you can grow.
Where to check this for your own county
The best local source is University of Vermont Extension, the state’s land-grant extension service. Its staff work with county gardeners and see what actually grows in local soil. Two things are worth looking for. The first is a local planting calendar, which gives sowing dates adjusted to your area’s frost pattern. The second is the list of varieties trialled in your county, which tells you which mizuna, bok choy or mustard has done well in your conditions and which ones bolted or failed.
The extension office can also answer questions the general sources skip. It can tell you when flea beetle pressure peaks near you, whether soil testing is available, and how to read the results for brassicas, since Asian greens are in the same family as cabbage and prefer a pH near neutral.
A county recommendation beats a state one every time. A statewide recommendation averages together the lakeshore, the valleys and the high country, which behave like different climates. A county extension agent has seen how those differences play out in your area and can tell you which sowing date has worked over the years. Treat the state-level advice here as a place to start, then adjust it with what the local office says.
Checking this against your own garden
Your own observations outrank every date above. Three things to watch will tell you more about your microclimate than a calendar can.
- Soil warmth by feel. Push your hand a few inches into the bed in the morning. If the soil feels cold enough to numb your fingers, hold off on anything tender. Hardy leaf types will still sprout in cool soil, but slowly, and a bed that warms early tells you that you can start earlier than your neighbors on shaded ground.
- The first true leaves on an early test sowing. Sow a short row of mizuna as soon as you can work the soil. The first true leaves, which come after the rounded seed leaves, show that the seedlings are established. If they take longer than expected, your site is colder than the average.
- The first white lawn in fall. Note the morning you first see frost on the grass or on a car windshield. Compare that date with the Burlington window of October 3 to October 13. If frost comes days earlier at your place, shift your fall sowing earlier by the same margin.
Write the dates down for a season or two. A notebook will tell you more than any chart.
Common questions
Which Asian green is easiest to start with in Vermont?
Mizuna is the easiest. It germinates in cool soil, grows quickly, tolerates frost and recovers after cutting. Tatsoi comes next for fall.
Can Asian greens survive a Vermont winter outdoors?
Not without protection. With a coldest-month mean daily minimum of 12.9°F at the Burlington reference station, open beds will not carry greens through the winter. A low tunnel or cold frame extends the harvest well past the first freeze.
Is napa cabbage worth trying?
Only as a fall crop sown in midsummer, and only where the first freeze comes late enough for it to finish heading. In the hills and the Northeast Kingdom, stick to the faster leaf types.
When should I sow Asian greens for fall?
Count back from your first fall frost, allowing about a month to six weeks for the fast leaf types. At the Burlington station, that frost falls between October 3 and October 13, and it comes earlier in the mountains. The sowing dates are laid out in When to Sow Asian Greens in Vermont.