Autumn Sowing in Georgia — What to Plant in September and October

By late August every vegetable garden in Tbilisi looks the same: tomato stems past their prime, cucumbers finished, half the beds standing empty. Most gardeners stop right there and wait for spring — and give up an entire harvest every year.

In eastern Georgia, and especially in the Tbilisi basin, September and October are a full second sowing season. The soil is still warm while the air has already started to cool, and that is a combination you cannot get in spring.

Why autumn sowing works here

Spring sowing has two enemies: a late frost and the heat that arrives abruptly at the end of May. Spinach or lettuce sown in April often never builds up leaf at all — it bolts straight to flower.

In autumn the sequence is reversed. Through September the soil temperature stays in a range that favours germination for weeks on end, while the air cools a little more each day. The plant builds vegetative mass first and only then meets the cold — exactly the order that leafy and root crops want.

In the Tbilisi basin the first serious frost usually arrives towards the end of November or in early December. In the higher districts — Tsalka, Tetritskaro, Dmanisi — that date comes several weeks earlier, so the whole sowing calendar has to move forward with it.

September: leafy crops in open ground

The first half of September belongs to fast growers:

• Spinach — the most reliable autumn crop there is. Sown in September it crops in November, and if it overwinters as a leaf rosette it starts growing again in March.
• Radish — roughly a month from sowing to harvest, and noticeably sweeter in autumn, because there is no heat left to make it sharp.
• Coriander and dill — cool weather stops them bolting early and keeps them in leaf far longer.
• Rocket and leaf mustard — first pickings in two to three weeks.
• Loose-leaf lettuce — heading types no longer have time to mature from a September sowing, but leaf types do.

October and November: the overwintering crops

These follow a different logic — you sow now and harvest in spring:

• Garlic — from the second half of October to mid-November. Cloves go five to seven centimetres deep: deep enough to root before the frost, shallow enough that no leaf pushes above the soil.
• Winter onion sets — the same window, the same principle.
• Broad beans and winter peas — they overwinter and give an early spring crop.
• Pre-winter carrots and parsley — at the very end of November, into already-cold soil, so the seed does not germinate before winter.

Cover crops — soil that repairs itself

In most yards in and around Tbilisi the soil is heavy calcareous clay. A season of vegetables strips it and compacts it further. This is where a green manure earns its place — a crop you sow not for the harvest but for the ground:

• Rye — deep roots that break through a compacted layer.
• Vetch and field peas — they return atmospheric nitrogen to the soil.
• Mustard — fast growing, and it suppresses some soil pests.
• Phacelia — flowers into late autumn and draws pollinators.

Cut the cover crop before it flowers and work it into the top layer of soil. If you don't know what your ground is actually short of, start with a soil analysis — the choice of cover crop gets much more precise once you do.

Unheated greenhouses and low tunnels

An unheated polycarbonate greenhouse, or film stretched over hoops, extends the season at both ends. It does not mean tomatoes through the winter — it means spinach, lettuce, coriander, and radish still giving you leaf in December, and a start in February weeks ahead of open ground.

Ventilation is what decides it. On a sunny November day a closed greenhouse heats to summer temperatures inside and scorches young seedlings. In greenhouse design and construction, ventilation and condensation management are precisely what determine whether the structure works in the cold months.

Sowing technique on clay soil

Autumn sowing on heavy clay needs a different hand than spring:

• Sow shallower. Clay crusts over after rain, and fine seed buried deep cannot break through. One to two centimetres is plenty for spinach and radish.
• Cover the row with a thin layer of compost or sandy soil — that is what stops the crust forming in the first place.
• Water little and often until emergence, then switch to deep and infrequent.
• The September sun is still strong. Shading a newly sown bed for the first ten days makes a real difference to how evenly it comes up.

Three common mistakes

1. Planting garlic too early. Garlic set in September pushes leaf before the frost, that leaf is damaged over winter, and the bulbs come out small.
2. Sowing into an uncleared summer bed. Fungal disease left on tomato and cucumber debris moves straight into the new sowing.
3. Leaving soil completely bare. Rain washes the top, most fertile layer off an uncovered bed over winter. If you can't get a crop sown, at least sow a cover crop or mulch with straw.

Autumn sowing is one of those jobs that has to happen in the right week — a fortnight's delay changes the whole result. If you'd rather not track those windows yourself, that is what seasonal agrotechnical works and the yard care subscription are for. For the rest of the year, the plan is laid out month by month in the seasonal garden calendar for Georgia.