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Growing carrots

Why carrots fork, how to get the seed to germinate, and the spacing and soil they actually need.

Quick facts

Spacing between plants
3 in (8 cm)
Spacing between rows
12 in (30 cm)
Plants per square foot
16 per square9 per square, square foot gardening method
Sun
6+ hours a day
Water
1 in a week (25 mm)
Soil pH
6 to 6.8
Days to maturity
60 to 80 days
Yield per plant
0.2 to 0.35 lb (0.091 kg to 0.16 kg)
Start seeds indoors
Not started indoors — moving a seedling forks the taproot, and the taproot is the crop.
Transplant out
Not transplanted — sow where it will grow.
Direct sow
2 weeks before last frost

Square foot gardening figures come from Mel Bartholomew’s method and assume an intensive bed of amended soil. Spacing-derived figures assume conventional rows.

Scientific name: Daucus carota subsp. sativus. Spacing and planting dates checked against University of Illinois Extension. Yields, days to maturity and companion lists were never systematically checked — see how this data is checked.

Work it out for your garden

How many carrot plants fit in your bed?

128 plants — 4 rows of 32, at 3 in apart with 12 in between rows.

The spacing divides evenly into both dimensions, so the bed is fully used. Try staggered rows

Sowing dates for carrot

Enter your frost date for carrot sowing dates, or use the full planting date calculator for a whole season.

What will you harvest?

1.2–2.1 lb over the season, from 0.2–0.35 lb per plant. Add other crops

This page has the numbers for carrots: 3 inches between plants with 12 inches between rows, sixteen to a square foot, direct sown three weeks before your last frost, an inch of water a week, and a fifth to a third of a pound per root in 60 to 80 days.

Carrots need one thing the numbers do not capture: twelve inches of loose, stone-free soil with nothing rich added. The three sections below cover that, the two to three weeks of damp surface that germination needs, and the thinning step that is skipped more often than any other in the garden.

Soil first

A carrot is a taproot trying to go straight down. Anything in the way makes it fork, twist or stop. What it wants is loose, stone-free soil worked to at least twelve inches, ideally deeper.

What it does not want is richness. Fresh manure and nitrogen-heavy fertilizer both cause branched, hairy roots — carrots are one of the few crops where adding compost right before sowing actively hurts. Improve the bed the season before, then sow into settled soil. Phosphorus and potassium are fine; nitrogen is the problem.

If your ground is stony or shallow, do not fight it. A raised bed or a deep container of loose mix will give better carrots than any amount of effort on unsuitable ground, and a short, blunt-rooted variety will manage where a long one cannot.

Sowing

Direct sow about three weeks before your last frost date, and again every few weeks for a continuous supply. Carrots do not transplant — the taproot is the crop, and disturbing it defeats the point.

Sow thinly, about half an inch deep, and firm the soil gently over the drill. Then the hard part: keeping the surface damp for the two to three weeks germination takes. A board laid over the row, or a strip of fleece, holds moisture and makes the difference between a row and a disappointment. Check daily and water gently with a fine rose.

Radish seed sown along the same drill comes up in days, marks the row while you wait, and is harvested before the carrots need the space.

Thinning and spacing

Thin to three inches apart once seedlings are an inch or so tall, with 12 inches between rows. In a square-foot bed, sixteen carrots to a square is the right density.

Thin in the evening, in damp weather, and remove the thinnings from the bed rather than leaving them. Crushed carrot foliage smells strongly and that smell is exactly what carrot rust fly navigates by.

Water and care

An inch a week, steadily. Irregular watering causes splitting: a dry spell followed by a soaking makes the root swell faster than its skin can grow. Mulching between rows once the plants are established evens things out and keeps the crowns covered.

Draw a little soil over the shoulders as the roots swell to prevent green tops.

Harvest and storage

Pull a test carrot at about sixty days to see how they are doing. Loosen the soil with a fork before pulling in heavy ground, or you will snap them.

In cool weather carrots hold in the ground for weeks and get sweeter after a frost, which makes them one of the best crops to leave in place and harvest as needed. Where the ground freezes hard, a thick mulch extends that considerably. For storage, twist the tops off — leaving them on draws moisture out of the root — and keep them cold and damp.

Growing alongside carrot

Good neighbours

Onion, Leek, Lettuce, Rosemary

Keep apart from

Dill, Parsnip

Watch out for

  • Forked roots in stony soil
  • Carrot rust fly
  • Green shoulders
  • Slow, patchy germination

Companion planting pairings are traditional garden practice rather than settled science. Spacing, sun and water do far more for a crop than its neighbours do.

Carrot questions

Why are my carrots forked and stubby?
Something stopped the root going down. Stones, a compacted layer, or fresh manure and heavy nitrogen, which make the taproot branch. Carrots want loose, stone-free soil at least twelve inches deep and nothing rich added before sowing. If your soil is heavy or shallow, grow a short stubby variety or use a deep container instead of fighting it.
Why did my carrot seed not come up?
Carrots germinate slowly — two to three weeks — and the seed is tiny and sown shallow, so the surface must stay damp the whole time. One dry afternoon can finish a whole row. Cover the drill with a board or a length of fleece to hold moisture, water gently every day, and be patient before writing the row off.
Do I really need to thin carrots?
Yes, and it is the step most often skipped. Unthinned carrots compete and you get a row of thin roots instead of a row of carrots. Thin to about three inches apart once the seedlings are an inch tall, and do it in the evening in damp conditions, since the crushed foliage smell attracts carrot rust fly.
What causes green tops on carrots?
Sunlight on the shoulder of the root, which produces chlorophyll and a bitter green band. It is harmless and easy to prevent: draw a little soil or mulch over the crowns as they swell. It is more common in light soils and in varieties that push out of the ground.
When should I harvest carrots?
From about sixty days for a young carrot, and up to eighty or more for a full-size root. Pull one to check rather than guessing from the tops. Carrots hold in the ground well in cool weather and sweeten after a frost, so in autumn there is little hurry. In warm weather a carrot left too long goes woody.
Can I grow carrots in a container?
Well, provided it is deep enough. Twelve inches of loose mix suits most varieties, and short or round types will manage in eight. A container has the advantage of being stone-free and easy to keep damp during that slow germination, which removes the two hardest parts of growing carrots.

Other crop guides

Calculators for this crop

Last updated

Written by Muzamil Ali. The figures in the quick-facts table are typical published ranges that have not yet been checked against a primary source, so treat them as a starting point and defer to your local extension service. See the disclaimer and how these pages are made.