The correct spacing of beetroot seedling is important for good crops. They should never be crowded too closely - though they often are!
The exact spacing depends upon the variety of beetroot that you are growing. As a general rule, the early varieties which are sown under cloches in February - March, can be sown in rows about 7-8in apart. These varieties - Detroit etc - will grow very fast. Thin them out to 4in between plants.
The main crop varieties, which are normally sown in May or June, need to be in rows that are 12in apart, and can be thinned to just 1in between seedling plants.
Late Autumn Beet, and those grown for storage are normally sown in June or July, and the rows can be 8in apart and the seedling plants thinned to around 3 - 4 in apart.
A healthy Beetroot crop - just harvested and fresh for the table!
Beetroot which is being grown specifically for Pickling can be sown in close rows - no closer than 3in apart, with just 3in between the seedling beet plants. It is important to crop the beetroot grown in this manner as soon as they are large enough for pickling purposes. Don't be tempted to leave them in the ground, hoping for a larger crop. Close-grown beetroot, will simply turn into coarse roots if left too long.
Neither try thinning them to leave some in the ground longer, for the formative growing will again predispose them to growing into 'fibrous' beetroot. If you want good large maincrop beetroot, then grow them and space them as such, right from the start.
Beetroot are relatively short-term crops, and need to get as much as they can from the soil in order to mature quickly, and produce the soft succulent globes that we are all so fond of (!). They do not have time on their hands - such as onions for instance - to linger in the soil. Spacing is important for quality crops. You should not try to 'compensate' by force feeding. Give them the space, in a good fertile soil, and you will end up with good, fleshy balls of nourishment - and a taste to go with it, that is not too 'earthy'
Do save the twisted off
foliage tops. They make a good addition to the compost heap, and
rarely carry any disease!