Thinning Seedlings

After sowing seed, you may have more seedlings come up than you need. A few extra plants are useful in case of losses by pests and diseases or when unsure about how many plants you need. Too many seedlings though, growing too close together, produce weak plants. The surplus needs to be removed, using a simple technique outlined below.

Why thin seedlings?

Seedlings restrict each other’s growth when overcrowded. They stretch up to compete for light, making straggly plants rather than short, strong ones ready for potting on or transplanting. The trick is to thin seedlings before they compete too much so you’re left with the right number of vigorous plants capable of producing a crop. 

The process of thinning 

Thin in stages, leaving the sturdiest and most vigorous seedlings at the correct spacing. It also helps to practise good seed sowing (A18) so enough germinate as a back-up, but plants aren’t wasted unnecessarily. Sometimes gardeners are reluctant to remove healthy seedlings. Luckily, you’ll see the benefit once the remaining plants grow on strongly. Thinnings can be eaten or added to the compost heap.

Needless to say, wash hands after handling compost and soil.