Stop being kind to your carrots.
Crowded rows grow thin, tangled roots. Thin to a finger apart, twice, and eat the second lot as baby carrots.
Carrot seed comes up crowded, and crowded carrots stay thin and tangled. Thin twice: to about 3 centimetres apart when the seedlings are 5 centimetres tall, then to about 5 centimetres, a finger width, when they reach 12 to 15 centimetres. Snip or pull the extras gently and eat the second lot as baby carrots. Beetroot comes up in clumps from its cluster seed and wants about 10 centimetres; radish wants about 5. Forked carrots are a soil problem, not a spacing one.
Nobody likes pulling up a healthy seedling. It feels like waste, so the row is left as it came up, a green fuzz of a hundred carrots where twenty would do, and in three months the harvest is a handful of pencils wrapped around each other. Thinning is the kindest thing you can do to a carrot row, and the step almost everyone skips.
Why the row comes up crowded
Carrot seed is tiny and hard to sow evenly, and it is slow, one to three weeks to come up and usually about two. Most of us hedge against a patchy row by sowing more than we need, and the seed obliges by coming up all at once, shoulder to shoulder. Beetroot has its own version of the problem: every beetroot "seed" is a corky cluster of two or three true seeds, so each one comes up as a small bunch.
What crowding does to the roots
Left crowded, carrots fight for light, water and room, and you get a tangle of thin, stunted roots. Gardening Australia's Tino Carnevale puts it plainly: carrots do not like a crowd. Roots pressed hard against each other can also come out misshapen.
Forking and twisting are a different problem with a different cause. A carrot root forks when its tip meets something it cannot push through, a stone, a clod, a hard layer, or when it is fed too richly with fresh manure, blood and bone or pelletised manure. Transplanting can do it too, which is why carrots are sown direct rather than bought as seedlings. Spacing gives you size and shape; soil gives you a straight root.
How to thin carrots: two passes
Two passes leave you a margin if a few seedlings fail.
- When the seedlings are about 5 centimetres tall, roughly four weeks in, take out the weakest until there is about 3 centimetres between the ones you keep.
- When they reach 12 to 15 centimetres, thin again to about 5 centimetres, a finger width, between plants.
- Snip the extras off at soil level with scissors, or pull the small ones gently, so the roots you are keeping are not disturbed. Carrots are particularly sensitive to being moved.
- Firm the soil back and water the row.
The second-pass thinnings are baby carrots. Eat them. That is the moment the job stops feeling like waste.
Beetroot and radish
Beetroot comes up in clumps because of its cluster seed. Thin each clump to the strongest seedling at about 10 centimetres apart, or leave the clump and twist out the biggest as baby beets, which Gardening Australia's Millie Ross does deliberately. Every thinning is a salad leaf.
Radish is the quick one, usually ready in four to six weeks. Thin to about 5 centimetres or the roots tend to stay small. Woody, pithy or split radishes are a heat, drought and timing problem rather than a spacing one: water evenly and pull them on time.
Sow thinly and skip half the job
The best thinning is the thinning you never have to do. Mix a packet of carrot seed with a cup of dry sand and pour the mix thinly along a shallow drill, aiming for a plant every few centimetres. Then keep the row damp for the whole one to three weeks of germination; a plank or a strip of hessian laid over the row holds the moisture and comes off the day the first green shows.
Baby carrots come from about 8 to 10 weeks, full size at 12 to 16 weeks. Brush the soil off the top of a root to check: a shoulder about 2.5 centimetres across is ready. Pull them before they turn woody or run to flower.
A note for every zone
Thinning is the same everywhere. Timing is not. Sydney, Melbourne, Adelaide, Canberra and Hobart sow carrots through spring into a bed that is only warming up, and the row may take the full three weeks to show. Perth and Brisbane have an easier carrot season in autumn; a spring sowing there wants shade cloth over the row until the seedlings are through, and the first thinning done in the cool of the evening.
Carrot rust fly (Chamaepsila rosae, formerly Psila rosae), the pest overseas gardeners thin around, is not in Australia. If you ever find maggot tunnels in a carrot root, report it to the Exotic Plant Pest Hotline on 1800 084 881.
Grow it: seeds in stock
Four root crops that all want the same thinning routine.
Carrot Heirloom Mixa spread of colours from one packet, sown thin with sand and thinned twice.See the seeds
Carrot All Seasonsthe dependable orange carrot for a first row, in every metro.See the seeds
Beetroot Bulls Blooddark leaves worth thinning for the salad bowl, and a sweet root when thinned to 10 centimetres.See the seeds
Radish Heirloom Mixusually four to six weeks from sowing, and the quickest lesson in why spacing matters.See the seeds
Be unkind to the row once and the row repays you all season. The other half of a straight carrot is a fine, stone-free bed and a shallow sowing, and our lesson on how deep seeds really want to go covers the drill depth that carrot seed wants.
Frequently asked questions
Can I transplant the carrot seedlings I pull out?
No. Carrots resent root disturbance and a transplanted seedling usually forks or stalls. Eat the second-pass thinnings and compost the first.
Why are my carrots forked when I thinned them properly?
Forking is almost always the soil or the feed: stones, clods, a hard layer under loose topsoil, or a bed fed with fresh manure, blood and bone or pelletised manure. Dig the bed fine and deep, skip the rich feed, and sow direct.
Is it too late to sow carrots now?
No. Carrots are sown through spring in Sydney, Melbourne, Adelaide, Canberra and Hobart, and in Brisbane and Perth they are easier again in autumn. Sow thin, keep the row damp, and thin twice.
