Seed packets will tell you the best spacing distances to achieve for each type of crop being grown, but here are some examples:
The summer salad varieties are thin, so there are gaps of approximately 2.5cm (1”) between each plant.
Larger varieties need 15cm (6”) between plants.
Early cropping carrots need final spacings of about 5cm (2”) between each plant and main crop distances of around 10cm (4”).
Carrot seeds are tiny, which makes it virtually impossible to avoid sowing too thickly. As a result, they’ll need thinning several times whilst growing.
Start to thin when greenery is about 2.5cm (1”) high, ideally just after a rain shower as this loosens the soil to make it easier to remove the seedlings.
Expect to make two or three further thinnings before the crop reaches maturity. The first few thinnings will be tiny, but the final ones should reveal baby carrots perfect for the kitchen.
Mix fast growing radish seed with carrot seed when sowing. The radish will be ready to harvest much quicker than the carrots and harvesting the radish will be an easy way of thinning the carrot row in its early stages of growth!