I had success planting early Leeks in module-started clumps of 4 or 5 plants last year. Is this method also suitable for the more hardier later leeks like Musselburgh or are they better planted individually?
I planted these in clumps and have been very happy with the results, which I am still harvesting at a modest size. I dont like great big ones and by planting in clumps of 2 or 3 I have a good crop of medium size leeks. And I avoided the back ache of planting individually.
Musselburgh is a Scottish variety and well adapted to cold winters, with a short stem. Dibbing it deep also helps protect the plant from severe frost. But in less bitter winters, other varieties such as Apollo and Bandit are good, with longer stems, and do well as clumps. As Bluebell says, it depends what you want to harvest, and module-sown leeks are easier to pull, without using a spade.