When to Sow Carrots in the UK

Introduction

Carrots are best sown outdoors in the UK from March to July, once the soil has started to warm. February sowings are possible under cloches, fleece, cold frames, or in a greenhouse bed, but unprotected outdoor soil is often too cold for reliable germination.

For a longer harvest, sow small rows every two to three weeks instead of planting one large batch. Later sowings in June and July can still crop well, especially if you keep the seedbed moist and choose quick-maturing varieties.

Carrot seed is small and slow to germinate, so timing matters. Aim for soil around 7–10°C or warmer, use light, stone-free soil, and keep the seedbed evenly moist until seedlings appear.

Carrot Sowing Season in the UK

The main carrot sowing season in the UK runs from March to July.

Carrot seeds germinate best once soil temperatures reach around 7–10°C. If the soil is colder than this, germination can be slow and uneven. This is why March or April is usually a better starting point than very early spring.

You can sow earlier in February if the bed is protected with cloches, fleece, a cold frame, or greenhouse cover. Later sowings in June and July can still crop well, but they need steady moisture and enough time to mature before autumn growth slows.

When to Sow Carrots Month‑by‑Month in the UK

Here is the UK carrot sowing season broken down month by month. The main outdoor window is March to July, but protected February sowings and late July sowings can work in the right conditions.

February

February is early for carrots in most UK gardens. Sow only if you can protect the bed with cloches, fleece, a cold frame, or a greenhouse bed. Outdoor soil is often too cold for reliable germination, so seeds may take two to three weeks to appear.

Best for: very early carrots under protection.

March

March is the first realistic outdoor sowing month for many UK gardeners, especially in mild areas or well-drained beds. Wait until the soil is workable and no longer cold or waterlogged. If conditions are still poor, delay until April.

Best for: first outdoor rows and early varieties.

April

April is one of the most reliable months to sow carrots in the UK. Soil temperatures are usually warmer, germination is quicker, and seedlings establish more evenly. This is a good time to sow both early carrots and the first maincrop varieties.

Best for: reliable outdoor sowing.

May

May gives warm soil, longer days, and strong germination. Carrot seeds often appear within 7–14 days in good conditions. This is a useful month for maincrop carrots and continued succession sowing.

Best for: maincrop carrots and steady harvest planning.

June

June is still a good month to sow carrots, especially for succession crops. The soil is warm, so germination is usually quick, but watering becomes more important. Keep the seedbed moist until seedlings appear.

Best for: late summer and early autumn harvests.

July

July is usually the final reliable month to sow carrots outdoors in the UK. Choose quick-maturing varieties and keep the soil evenly moist, as dry summer seedbeds can stop germination.

Best for: final autumn crops.

August

August sowings are possible in mild areas or under protection, but they are less reliable. Shortening days mean carrots grow more slowly, so roots may stay smaller. For most gardeners, July is the safer final sowing month.

Best for: experimental late sowings only.

Best Conditions For Sowing Carrot Seeds

Carrot seeds germinate best when the soil is warm, fine, and evenly moist. They are small seeds, so poor seedbed preparation often leads to patchy rows.

For the best results:

• Soil temperature: Aim for soil around 7–10°C or warmer. Cold soil slows germination.
• Soil type: Use light, loose, stone-free soil. Heavy or stony ground can cause forked roots.
• Sunlight: Choose a sunny position where the bed warms quickly in spring.
• Moisture: Keep the seedbed evenly moist until seedlings appear.
• Fresh manure: Avoid freshly manured ground, as rich soil can cause carrots to fork.
• Spacing: Sow thinly in shallow drills about 1cm deep, with 25–30cm between rows.

If your soil is heavy, carrots often do better in raised beds, deep containers, or a bed that has been loosened and cleared of stones.

How To Sow Carrot Seeds

Once you know when to sow carrots, the next step is getting the seedbed right. Carrot seed is small, so careful sowing helps improve germination and gives the roots space to grow straight.

Succession Sowing Carrots

For a steady harvest, sow short rows of carrots every two to three weeks from March through June or July.

This works better than sowing one large row at the start of the season. Each batch matures at a slightly different time, so you get fresh carrots over a longer period and avoid lifting too many at once.

A simple UK carrot succession plan:

Common Mistakes When Sowing Carrots

Carrots are easy to grow, but a few simple mistakes can lead to poor germination, forked roots, or patchy rows. Most problems come from cold soil, overcrowding, poor seedbed preparation, or letting the soil dry out.

Sowing In Cold Soil

Carrot seeds germinate slowly in cold soil. If the soil is below about 7°C, seeds may sit for weeks before appearing, or fail altogether.

For most UK gardeners, March or April is a more reliable starting point. If you want to sow earlier, use cloches, fleece, or a cold frame to warm the soil.

Sowing Too Thickly

Carrot seed is tiny, so it is easy to sow too much. Crowded seedlings compete for space and often produce thin, twisted, or misshapen roots.

Sow thinly in shallow drills, then thin seedlings gradually once they are large enough to handle.

Heavy Or Stony Soil

Carrots grow best in light, loose, stone-free soil. Heavy clay, compacted ground, or stones can cause roots to fork or twist.

Before sowing:

• Remove stones and debris
• Break up compacted soil
• Rake the surface into a fine seedbed

If your soil is very heavy, raised beds or deep containers are often easier.

Letting The Seedbed Dry Out

Carrot seeds need steady moisture to germinate. If the surface dries out after sowing, germination can be poor or uneven.

Water gently with a fine rose and keep the seedbed evenly moist until seedlings appear.

Adding Fresh Manure

Fresh manure or strong nitrogen fertiliser can make carrots fork and grow unevenly.

Carrots do best in ground improved in a previous season. If a bed has recently been manured, use it for another crop and sow carrots somewhere else.

How Long Do Carrots Take To Grow?

Most carrots are ready to harvest around 8–16 weeks after sowing, depending on the variety and growing conditions.

Early carrots are usually best eaten fresh. Maincrop carrots take longer, but they produce larger roots and are better for storing.

For harvesting advice, link to your full when to harvest carrots in the UK guide here.

FAQs: When to Sow Carrots in the UK

Below are some of the most common questions gardeners ask when planning when to sow carrots in the UK. These quick answers explain the best time to sow carrot seeds, how late you can plant them, and what conditions help carrots grow successfully.

For more gardening advice and seasonal planting guidance, you can also explore the resources available at the Royal Horticultural Society (RHS).