Transplanting | Thinning
Courgettes need wide spacing
Vegetables need enough space for each plant to develop to a usable size. The amount of space varies for each vegetable and may even vary between varieties of a particular vegetable. The seed packets give suggested spacings for each variety.
Some vegetables, such as peas, beans, scallions, radishes, potatoes and onion sets, are sown at their final spacing and need no further adjustment. Others do need to be spaced and there are two ways of achieving the final spacing.
Many crops cannot be transplanted. The root crops – carrots, parsnips, turnips, swedes and beetroot – would form a useless forked root if transplanted because of the damage caused by lifting. These must be thinned to their final spacing.
Parsnips after preliminary thinning
Sow the seeds of these crops thinly. Too many seedlings emerge and the surplus is simply pulled out, choosing the strongest to grow to maturity. It is a good idea to thin in two stages. If the final spacing is made when the plants are still young and vulnerable, gaps will be left if some die, or are damaged, for instance, by snails. A preliminary thinning, to half the final spacing, will provide substitutes if there are casualties.