I used exactly the same technique as last time, so I won't describe it again, but let me just show you what I did with the leftovers:
Some of the big 35-litre pots in which I have been growing potatoes are gradually becoming vacant, so I thought this way of using them would be better than just throwing away the spare Leeks. There were four of the "Apollo" left over, and six of the "Toledo".
When the final Kohlrabi comes out my last batch of Leeks will go in. I don't think I will be able to fit in another nine plants as originally intended. It might just have to be six.
Still, if space is short at least I will be able to put a few more into pots. This has some advantages, you know: I will be able to move them around the garden if necessary, for instance to maximise the amount of light they get.