The Best Asian Greens for Nunavut

Fast, cold-tolerant leaf greens are the best bet in Nunavut: mizuna, tatsoi, komatsuna and baby pak choi, cut young. Heading types such as napa cabbage want a longer season than the territory gives. Even the quick ones do better in a sheltered bed, because open ground warms late and cools early. Here is how to sort the types, what fails, and how the answer shifts from one community to the next.

The short answer for Nunavut

Choose greens that give a usable harvest within about four to six weeks of sowing, and cut them as baby leaf instead of waiting for full size. The weather record from Rankin Inlet A, the reference station, shows why. The mean last spring frost falls on June 19 and the mean first fall frost on September 13, which leaves about 86 frost-free days between them. Those are midpoints. In one year out of two, the last frost comes later than June 19, and in one year out of two the first frost arrives before September 13. The figures come from the 1981-2010 Canadian Climate Normals.

Which Asian greens grow fast enough?

Typical seed-packet days, counted from sowing, sort the types quickly. Treat the numbers as rough, since they vary by variety and by how cold the bed stays.

Mizuna and tatsoi come first because they keep growing in cool weather and take a light frost without damage. Komatsuna is a close third, with a tougher, more upright leaf that handles wind better than most.

How should you treat the frost window?

Never treat June 19 as a safe sowing date. It is the middle of a spread, and half of all years run later. The same goes for September 13 at the other end. The coldest month averages a daily minimum of -34.3 °C (-29.8 °F), and Nunavut sits in Canadian hardiness zone 0a for the reference city. That zone system is built on seven climate variables and does not convert to a USDA zone. Nothing in the garden overwinters outdoors here, so every crop is an annual that has to finish inside the summer. For the sowing sequence itself, see When to Sow Asian Greens in Nunavut.

What will not work here

Anything that needs 60 to 80 days to form a dense head will fail. Napa cabbage is the clearest case. Eighty-odd frost-free days on average sounds like room, but the soil is still cold in June, so seed sown the day of the mean last frost sits idle for weeks. A fall frost that arrives before September 13 then catches the crop half-formed. Full-size pak choi and gai lan, which are grown for thick stems and large plants, run into the same wall.

Why do some greens bolt in the Arctic?

Summer daylight in the territory is very long, and near the solstice the sun barely sets. Many Asian brassicas read long days as a signal to flower, and cool nights followed by a warm afternoon add to the push. Pak choi and napa are the most prone to it. A plant that sends up a flower stalk at 6 inches has stopped making the tender leaves you wanted. Quick baby-leaf cutting dodges the problem, because the harvest is over before the stalk starts. Some growers also cover beds with an opaque cloth for part of the day to shorten the light, though that is extra work for a small gain.

What else defeats a garden here?

Wind is the second big problem. Tall, thin-stemmed leaves tear and dry out in an exposed bed, and a sheet of row cover or a low windbreak often matters more than the variety. Soil is the third. Ground in much of the territory is thin, rocky and frozen below the surface for most of the year, so sowing straight into native ground gives poor results. Raised beds filled with imported or composted soil warm faster and drain better. Overwintering mustards or fall-sown greens, which works in milder climates, is out of the question at a January mean minimum of -34.3 °C.

Heat, which sinks Asian greens across much of the continent, is almost the one threat you can ignore. The failure here comes from cold soil, short days to maturity and bolting, not from a hot, dry July.

What changes across Nunavut

Nunavut is not one garden. It stretches from the High Arctic islands down to the southern shore of Hudson Bay, a span of many degrees of latitude, and the Canadian hardiness zone of the reference city (0a) does not describe the whole territory. There is no single answer, and the spread inside its borders is wide. The Rankin Inlet frost dates also come from one station. Northern communities run weeks behind them, with a later spring thaw and an earlier fall frost, and some may have no dependable frost-free stretch at all outdoors.

If you live north of Rankin Inlet, shift toward protection. Put the fastest greens (mizuna, tatsoi) in a cold frame, a low tunnel or a greenhouse, and skip the slower types completely. Coastal sites are often slower to warm in spring because of sea ice and cold water offshore, so sowing a week or two after the bed clears of snow is wiser than going by the calendar. Inland, sheltered sites can warm sooner, but they also tend to see sharper night frosts.

Do not guess your own zone from this article. Look up your community on Canada’s Plant Hardiness Site, which lists zones by municipality. Keep in mind that it uses the Canadian system, and a Canadian zone number cannot be turned into a USDA one. For the full crop-by-crop picture, Growing Asian Greens in Nunavut covers the territory as a whole.

Where to check this for your own county

Nunavut has no counties. It is divided into three regions, Kitikmeot, Kivalliq and Qikiqtaaluk, and the practical unit for a gardener is the community. Start with Agriculture and Agri-Food Canada for northern and cold-climate growing guidance. Then look up the nearest weather station’s frost dates in the Canadian Climate Normals, because a station 200 miles away tells you little.

Two things matter most when you look. One is a local planting calendar, ideally one built from the nearest station and not from a southern city. The other is a list of varieties trialled under northern conditions, since a variety that performed in a trial near you beats one that merely looks good in a catalog. Community greenhouse groups and the hamlet office are often the quickest way to find that kind of local knowledge. The Iqaluit Community Greenhouse, for one, has long run as a hub for northern growers.

A recommendation from someone growing in your own community outranks a territory-wide one every time. Territory-wide guidance, like the Rankin Inlet figures above, gives you a starting point and a sense of the odds. It cannot account for your snowdrift, your wind or the slope of your yard.

Checking this against your own garden

Your own observations outrank every date here. Three are worth watching, and none needs an instrument.

• Soil warmth by feel. Push your hand into the bed to wrist depth. If it feels cold and you cannot keep it there comfortably for a few seconds, seed will sit and may rot. A bed that feels cool but not numbing is ready for mizuna and tatsoi. This also tells you how much a raised bed or dark cover is helping compared with open ground.
• Snowmelt in the bed. Note the day your bed clears of snow and stays clear. A bed that clears two weeks before your neighbor’s has a real microclimate advantage, usually from shelter, slope or a south-facing wall.
• The first true leaves. Sow a small test row early. The first pair after the seed leaves are the true leaves. If they appear within about a week or two and look sturdy, the bed is warm enough. If they are slow, pale or leggy, the bed is too cold or too shaded.

Keep notes for a couple of seasons. Your own record will outlast any published average, and by the second year it will tell you more about your site than a station hundreds of miles away.

Common questions

Can you grow bok choy in Nunavut?

Yes, as baby pak choi, picked young, and best in a sheltered bed or greenhouse. Full-size heads need more time than the season reliably gives, and the plants tend to bolt under the long summer days.

Do Asian greens survive frost?

Mizuna, tatsoi and leaf mustards handle a light frost well, and cover helps them through a harder one. Nothing survives the winter outdoors, though, where the coldest month averages a daily minimum of -34.3 °C.

Do you need a greenhouse?

Not everywhere, but the farther north you are, the more it helps. Near Rankin Inlet, a raised bed with row cover can work for the fastest greens. In colder northern communities, a cold frame or greenhouse is the dependable route.

What is the safe date to sow outside?

There is none. The mean last spring frost at Rankin Inlet A is June 19, and in one year out of two the last frost comes later. Sow when the bed is clear of snow and the soil no longer feels numbing, and keep cover on hand.