Vegetables for autumn and winter harvest — what to sow in August and September

August in the vegetable garden is not the end of the season but its second act. Beds free up after garlic, onion, early potato and broad bean harvests, the soil is warm — the best conditions for filling empty spaces with vegetables for autumn and winter harvest. Growing your own vegetables year-round is one of the strongest gardening trends — and in August and September the window closes on the last wave of it for this year. This guide shows what to sow, and when.

Why the second half of summer is a good moment

Sowings in August and September have several advantages over spring ones. The soil is already warm, so seeds germinate quickly. Many leafy vegetables actually taste better in the cool than in the heat — lettuce and spinach bolt less often in August than in July, and cool nights soften their flavour. Pest pressure and spring diseases are lower. On top of that, you make use of ground that would otherwise sit empty until spring.

The timing of jobs across the whole season is gathered in the garden calendar; below are the most important vegetables for this time.

Fast leaf and root vegetables

If you want a harvest this autumn, go for short-cycle species:

• Radish — the fastest of the lot, ready in 4–6 weeks. Autumn sowings are less prone to woodiness and splitting than summer ones.
• Arugula and lettuce — as cut-and-come-again crops: sow densely and harvest young leaves repeatedly.
• Spinach — an autumn sowing gives juicy leaves, and in a mild winter the plant overwinters and takes off early in spring.

Vegetables that overwinter in the ground

The real reward for sowing in August is a harvest at the hardest moment — late autumn and winter, when shop-bought leafy vegetables are at their most expensive:

• Corn salad (known in Germany and Switzerland as Feldsalat) — the most popular winter salad. Extremely frost-hardy, sown from August to September, harvested as rosettes throughout the winter under a light fleece cover.
• Kale — a leafy cabbage that not only takes frost but actually sweetens after it. From an August sowing you harvest leaves from autumn through winter into early spring.

Chinese cabbage and Swiss chard — for the autumn bed

• Chinese cabbage is the classic follow-on crop: it grows fast, and when sown in summer under a shortening day it bolts less than a spring sowing. An August sowing forms heads for autumn.
• Swiss chard — the leafy form of the beetroot, harvested as a cut-and-come-again crop: after the outer stalks and leaves are cut, it regrows and yields until the frosts, and with cover into early spring as well.

Practice: sowing, watering, cover

August soil is often dry, so water the drills thoroughly before sowing, then sow and keep the top layer moist until emergence — this is the most common cause of failed summer sowings. The rules for watering are gathered in the watering guide.

Beds after heavy-feeding vegetables (brassicas, cucurbits) need compost before you resow — how to do this sensibly is described in the fertilising guide. Do not follow vegetables of the same family with themselves (crop rotation); good and bad neighbours are shown in the vegetable companion guide.

As the day shortens, growth slows, so the later you sow, the more important a white fleece becomes — it lifts the temperature by several degrees, speeds up emergence and shelters the first frost. It is what turns the „last sowing of the season“ into a real winter harvest. What else to do in the garden before winter is gathered in the guide to preparing the garden for winter.