Growing Through the Dark: Shetland and Orkney's Six-Hour Winter Days

Day length depends on latitude, not temperature or weather, and that's what makes Shetland and Orkney different from the rest of Scotland, not just a few degrees colder or a bit further from everything. Lerwick sits at roughly 60°N and Kirkwall just under 59°N, both closer to the Arctic Circle (66.5°N) than to London. Around the winter solstice the sun clears the horizon for barely six hours, and even then it never climbs far above the rooftops.

It's a gradient rather than an on/off switch: Caithness, Sutherland and the Western Isles sit at intermediate latitudes and see a milder version of the same effect, becoming progressively less extreme moving south.

How short, exactly

Sunrise, sunset and total daylight on the 2026 winter solstice, 21 December:

Kirkwall gets roughly 22 minutes more daylight than Lerwick on the solstice, Lerwick trails Edinburgh by about 70 minutes and Kirkwall by about 47, while London is about two hours ahead of Lerwick and about an hour and a half ahead of Kirkwall. That's not a rounding difference: it's up to two fewer hours of light every day for weeks either side of the solstice.

"Daylight" here means sunrise to sunset, which isn't the same as useful light for plant growth or outdoor work. Civil twilight, the time either side when it's still light enough to work without artificial light, adds roughly another hour and three quarters to two hours in Lerwick and Kirkwall, stretching the outdoor working window to around 7¾ to 8 hours. But the sun sits low on the horizon even at midday, delivering weak, glancing light, and winter cloud cuts into even that reduced total, so six hours is a best-case ceiling, not a guarantee.

For the opposite extreme, Shetland's June days of nearly 19 hours (the "simmer dim"), see growing under the simmer dim.

What six hours of weak winter light rules out

Winters in both island groups are generally mild for the latitude, and growers there say wind, not temperature, is the main problem. So light is the real bottleneck through the darkest stretch:

• Sowing outdoors is pointless. GerminationA seed sprouting: breaking dormancy and putting out its first root and shoot, given the right warmth and moisture. Full definition → depends on soil temperature and, for most crops, enough light for seedlings to establish, and neither is there. Nothing sown outdoors in late December will get enough light to grow away. It will sit, and because these winters tend to be wet rather than hard-frozen, the seed is more likely to rot in cold, waterlogged soil than simply stall.
• Transplanting is best avoided. A plant put out to establish new roots needs enough light afterwards to recover and photosynthesise. At six hours of weak light, recovery is slow to non-existent, and the plant sits exposed to wind and salt-laden air off the Atlantic and North Sea. That near-constant stress is part of why Shetland's traditional "plantie crubs", small circular dry-stone enclosures used to raise seedlings (mainly kale) out of the wind and salt spray, exist, and why a polytunnel there is chosen as much for shelter as for warmth.
• Growth is minimal. Too little light produces weak, pale, spindly growth and fewer flowers and fruit, because the plant can't make the food it needs. At six hours of low-intensity midwinter light, most edible crops are close to or under that threshold, so growth effectively pauses rather than continuing slowly.
• Gardening before or after the light window means working in the dark. With sunrise around 09:00 and sunset around 15:00, anyone with a working day either side of those hours is gardening, if at all, by torch or floodlight in December and January.

None of this means nothing can be done. The darkest six or so weeks around the solstice are a pause point, and the realistic approach is to use late November through mid-January for maintenance, protection and planning. As a rough working trigger, daylight climbs back above about 7 hours around 17 January in Kirkwall and 21 January in Lerwick, and that is when hardy sowings under cover become worth attempting again. Full outdoor sowing should wait considerably longer, closer to the last-frost timing on the frost date calculator.

What a polytunnel or greenhouse can and can't do

A polytunnel, greenhouse or cold frame protects whatever's already growing or dormant from wind, frost and waterlogging while the short day plays out. In an established Shetland or Orkney garden that means crops already in the ground or in pots, not seedlings started from scratch (the LED grow lights guide covers supplementing light for seed-starting, including monthly sunshine-hour comparisons for Edinburgh and Lerwick).

In an unheated structure through the darkest months, stick to hardy, established crops rather than tender vegetables. The RHS suggests hardy lettuce cultivarsA plant variety that arose or was bred under cultivation and is kept true by deliberate propagation, rather than a naturally occurring wild species. Full definition → and pea shoots, broad beans and peas to overwinterKeeping a plant alive and intact through the cold months, whether left outdoors, moved under cover, or stored dormant. Full definition →, and herbs in pots moved indoors to keep cropping longer. Kale, leeks and chard are commonly grown through winter in the open ground given wind shelter, and share the same tolerance for cold and low light. Heated glass changes the temperature but not the light: heated greenhouses are rarely cost effective, and a heated greenhouse in Lerwick in January still only gets six hours of weak sun.

A polytunnel isn't the only option. For a smaller plot, horticultural fleeceA lightweight, breathable fabric laid or draped over plants to trap a little warmth and keep off frost, wind and some flying pests. Full definition →, clochesA small, portable clear cover placed over an individual plant or short row to trap warmth and keep off wind, rain and pests. Full definition → or windbreak netting give a lighter version of the same wind and cold protection at a fraction of the cost, and suit a crofter or allotment grower who doesn't want a full structure.

Practical measures that help: keep glazing or polytunnel covers clean inside and out, since a dirty cover in a low-light location is losing light it can't afford to lose; add insulation such as bubble wrap (sufficient for many structures) to hold what warmth there is; anchor a polytunnel's cover and frame securely against wind and salt-laden gusts; repair small tears before the worst winter weather, since damage spreads fast in a gale; and use a south- or west-facing windowsill for potted plants that would otherwise sit in a dim corner. None of this adds daylight hours. It makes better use of the ones there are until day length recovers. The dark weeks also suit jobs that need no light to grow anything: checking stored vegetables, cleaning and mending covers and tools, and ordering seed.

The mechanism behind why some crops tolerate low light and others don't, long-day, short-day and day-neutral responses, is in the day length and photoperiod guide. In short, most crops grown through a Shetland or Orkney winter are there because they're hardy enough to sit through low light and cold, not because day length is triggering useful growth.

The light and mood angle

Shetland's own seasonal answer to the dark isn't a gardening one: Up Helly Aa, Lerwick's fire festival, is held on the last Tuesday of January, in the depths of winter.

NHS inform says a lack of light in the winter months affects mood, sleep and appetite, with symptoms typically starting in autumn and peaking in December, January and February. Gardeners in the far north live through more weeks of reduced daylight than those further south, though no data compares SAD outcomes between regions of Scotland.

NHS inform notes there is mixed evidence on light therapy, which may be more effective if used first thing in the morning. In Lerwick and Kirkwall, morning doesn't arrive until around 09:00 to 09:15 near the solstice, later than almost anywhere else in the UK. Getting outside during the brief daylight window each day, weather permitting, does double duty as garden time and light exposure.

The recovery is faster than the decline feels

Lerwick's daylight stretches from about 5h 49m at the December solstice to about 18h 55m by midsummer, a gain of around 13 hours across the year. That averages a little over half an hour a week, but it isn't steady: the gain is slower in the depths of winter (about 17 minutes a week through January) and considerably faster around the spring equinox. The six-hour window is real, and it is temporary.

Common questions

Sources