Mine went in yesterday, about the same size as first post.
Love planting leeks, always great fun.
Dib the holes.
Separate the leeks from your trays.
Pop them in the holes.
Get your plastic foot or so of old hose attached to your normal hose or in my case attached to a watering can, so you can carefully fill the hole.
Fill the holes with water.
Fix a few of the leeks that did not stand up so well.
Leave to grow on their own
Water once a week
Enjoy pulling carefully from December to April