Bulgarian Giant Leeks

I am only growing two varieties of potatoes this year. I planted these from green tubers which I collected last year as the ones I didn't want to eat. They seem to have made perfectly good seed potatoes. The International Kidney are my early new potatoes - I am digging them now and they are a beautiful waxy potato. These flowers here are from my others Sarpo Axona. I chose this variety because I was blighted quite badly last Summer, and this is one of the new varieties which is resistant to blight. Interesting flowers - I don't think I have ever seen so many flowers on a potato before. I think I will snip them all off with scissors, I don't want the plant putting energy into flowers and seeds. My New Zealand spinach has an interesting growing habit. Here you can see the plants have started to creep along the ground. I understand this plant just sprawls and provides rampant ground cover throughout the Summer. Haven't picked any yet, not big enough.
I planted out some of my leeks today. Don't leek seedlings grow so slowly? These and my other variety Musselburgh have been in pots for months now, they just slowly creep along. This one here is Bulgarian Giant. I saw a picture in a catalogue and couldn't resist. Apparently the shafts might get to 3 feet in length.
I will provide lots of well rotted manure and lots of water throughout the Summer and let's see if I end up with a Bulgarian giant! Has anyone grown them before?
They should take off in a couple of weeks time!