Early spring sown seeds and those being grown on windowsills – especially over radiators – Leggywhere the light comes from one side, may become tall, thin and weak.

This is caused by insufficient light combined with higher temperatures. Where possible, move them to a cooler position where they receive more light.

When pricking out or potting on these seedlings, the problem can sometimes be corrected by planting them deeper than previously – as long as their lowest leaves are still above the surface of the compost.