Top 5 Crops for Late or Second Sowing in Scotland

A seed packet's days-to-maturity figure isn't a fixed law of nature. It's a number generated under specific growing conditions, usually a spring or early-summer sowing, with lengthening days and soil warming up week by week. Sow the same variety in late July or August and you're working with the opposite budget: shortening days, soil that's already past its peak temperature and cooling, and less total light energy reaching the plant over the same number of calendar days. The packet doesn't know that. It just prints one number.

That mismatch is why so much generic sowing advice quietly falls apart once it's applied here. A crop that comfortably hits eight weeks to harvest when sown in May, with June and July's long days ahead of it, can take noticeably longer, or simply stall, when those same eight weeks have to be found in August, September and a fading October. None of this means late sowing is a bad idea. A second harvest from a bed that's already cleared is one of the better uses of a Scottish growing season. It means crop choice matters more than the calendar.

For the general technique of staggering sowings and working backward from your local frost date, see Succession Planting for Beginners; for when that frost is likely to arrive where you garden, see the Scottish frost dates reference. The question here is which crops to put in the ground once you've done that arithmetic.

1. Turnips (maincrop sowings)

Turnips are one of the few crops with a distinct maincropThe main, usually latest-sown and longest-growing type of a crop, grown for bulk and storage rather than an early harvest. Full definition → sowing window, July to mid-August, alongside the March to June window for early varieties. Maincrop turnips take about 10 weeks, and you pick them young: golf-ball size for eating raw or tennis-ball size for cooking, so you don't need to wait for a large root.

Turnip roots are not completely hardy, so it's safest to lift late-sown turnips before the weather turns really harsh and frosty, though in milder areas roots can stay in the ground under 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 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 → and be lifted as needed through early winter. Counting forward from a late-July sowing, the 10-week maturity figure lands in early October, check the frost dates reference for your own area to see how much margin that leaves before a hard frost is likely. Full sowing detail is in the turnip growing guide.

2. Radishes (salad and winter types)

Radish is the fastest crop on this list, and it's a cool-season crop, with the RHS monthly guide sowing salad radishes in spring, early summer and late summer, so the general advice already lines up with a late sowing. Salad radishes can be ready in as little as four weeks from germinationA seed sprouting: breaking dormancy and putting out its first root and shoot, given the right warmth and moisture. Full definition →, and are best harvested young, when the roots are about 2.5cm across. Avoid sowing in hot, dry conditions, which cause poor root development or premature flowering, but that's a hazard that mostly recedes by late July.

Winter radishes are larger, slower-growing types sown in July or August and are hardy, needing only cloches, biodegradable fleece or cardboard for protection in freezing weather. If you want a late sowing with cold tolerance built in rather than a race against the first frost, winter radish is the safer option; salad radish is the faster one. A cloche or cold frame left sealed on a mild, sunny winter day can overheat and encourage rot, so prop it open on anything but a cold day.

3. Beetroot

Sow beetroot regularly from spring through to mid-summer, with outdoor sowings from late March or April through to July once soil reaches at least 7°C. That's a narrower late window than turnip or radish: beetroot needs to go in by about the end of July, so it isn't a true August crop.

Within that window it's a reasonably fast grower: it can be ready in as little as 40 days, though 50 to 60 is usual, with roots usable from golf-ball to cricket-ball size. In mild locations where there's no risk of the soil freezing, late beetroot can be left in the ground until needed, and harvested roots stored in dry sand, compost or coir in a shed or garage should keep for at least a couple of months. Take the "soil doesn't freeze" condition seriously: ground frost is routine on plenty of Scottish ground, not just upland or inland sites. See the frost dates reference for how much this varies by region. Sown promptly in July, beetroot should size up before growth slows. Full detail is in the beetroot growing guide.

4. Spinach

Spinach is one of the few crops on this list with a late-summer-to-early-autumn sowing as a distinct cropping window: sow hardy varieties then for harvesting in autumn or early spring. Baby leaves can be cut in as little as a month, with mature leaves at around two months, and pacing matters: delay sowing while it's still hot to help germination, but don't leave it too late, plants need to be well established before winter sets in.

Hardiness depends on variety, and some spinach varieties tolerate cold far better than others, so check seed packets and choose a hardy type if you want it to overwinterKeeping a plant alive and intact through the cold months, whether left outdoors, moved under cover, or stored dormant. Full definition →. Hardy varieties can stand outdoors under cloches or biodegradable fleece from October, or autumn-sown spinach can go in a greenhouse border or in containers moved into a greenhouse or cold frame before cold weather sets in, which makes spinach one of the more forgiving crops here if your first sowing runs slightly late. Full detail is in the spinach growing guide.

5. Kohlrabi (late-season / purple varieties)

Kohlrabi's outdoor sowing window runs from March to July, or as late as August in locations with mild autumns, one of the more direct acknowledgements that this crop can be pushed later where the season allows it. Whether your own garden counts as a mild autumn site is worth checking against the frost dates reference rather than assuming, since it varies significantly across the country. Baby-sized roots are ready in as little as six weeks, full-size roots around twelve weeks, and the variety 'Kolibri' matures quickly, which makes it a useful choice when time is short.

For a late sowing, choose purple varieties, which tend to be hardier and slower to mature, ideal for sowing in late summer, a case where slower is the right trade-off. Sow several small batches at regular intervals, spreading harvests from May into November, or December in milder areas. Harvest between golf-ball and tennis-ball size so roots don't turn woody, and protect with cloches or fleece if you haven't finished before wintry weather. Full detail, including this crop's storage limitations, is in the kohlrabi growing guide and How to Store Kohlrabi for Winter.

Comparison table

Preparing the bed for a second sowing

A late sowing usually goes into ground that's already fed one crop this season, and that matters as much as the timing arithmetic above. Fork over and refresh the bed with a general feed or a light dressing of compost before resowing rather than assuming the soil that grew your first crop has enough left for a second, a bed drawn down by an earlier hungry crop like potatoes or brassicasThe cabbage family: cabbage, kale, broccoli, cauliflower, Brussels sprouts, kohlrabi, swede, turnip and more, sharing the same pests, diseases and rotation rules. Full definition → gives a late sowing a weaker start exactly when it can least afford to lose time. Newly sown seed also needs consistently moist soil to germinate regardless of the season, so a dry spell right after sowing is worth watering through even in a normally damp Scottish summer. Since the whole premise here is a shrinking light budget, give a late sowing the sunniest ground you have free rather than whatever bed happens to be empty, and keep it weeded. A cloche, cold frame, polytunnel or greenhouse extends the growing conditions further still.

Turnip, radish and kohlrabi are all brassicas, and if the bed you're clearing was growing another brassica this year, or a susceptible crop in recent years, check it against clubroot before resowing the same ground. Flea beetle is also a risk for all three in warm, dry spells (the damage to radish leaves is usually only cosmetic, but seedlings are more vulnerable); a floating fleece or fine mesh cover over the row from sowing keeps adult beetles off without any spray. See flea beetle for the full picture. Slugs will go after seedlings of any of the five, and a check on a mild, damp evening while seedlings are small catches most of the damage before it's serious.

What to skip: crops that look tempting but don't have the numbers

First-early peas take about 12 weeks to first harvest, second earlies 13 to 14, and maincrops 14 to 16, with the main outdoor sowing running March to June. A late-July sowing pushed through those 12-plus weeks lands in October at the earliest, right as light and warmth are dropping fastest, so peas and mangetout don't leave enough margin for a Scottish autumn.

Bulb onions are governed differently again: lengthening days trigger the formation of bulbs, so plants need to be growing strongly by late spring. Sowing after midsummer works against that trigger. Overwintering Japanese varieties such as 'Toughball' can be sown indoors in late summer or early autumn, but that's for a crop the following year, not a same-season second crop.

Common questions

Sources