Leeks sown this spring should be a nice healthy size by now, and it’s time to transplant them across into their final growing places.
Instead of just plonking them in the ground, encourage them to form long, white shanks by puddling them in. This is the rather quaint name for a technique which involves planting the seedlings at the bottom of a hole so that much of the plant grows underground, away from the light and therefore blanched pale and tender.
Make a hole where each seedling is to grow, around 10cm deep and 4cm wide. Then ease your leek seedlings gently out of their tray. Leave tops untrimmed, but if the roots are very straggly it's easier to get them in the hole if you snip away the longest.
Drop one seedling into each hole, then cover with water. Don't back-fill; as the water drains away, it'll pull enough soil down with it to cover the roots. As the seedlings grow, they'll swell to fill the space in the hole – and you'll get extra-long leeks next winter.
