transplanting leek seedlings

i was wondering what size modules my leek seedlings need pricking out into.  i am hoping to put them in after my first earlies come out.  i have not grown leeks before, as its only my second year of having an allotment, and last year i was not very organised,  at the moment they are on a south facing window cill in the front room, just about a cm high and still not fully vertical.  is this too soon to do anything with them? the vararities are musselbrough improved and lyon 2 , also, when ive pricked them out shall i still keep on the window cill, ( i havent got a greenhouse ) any advice would be much appreciated, thanks

I sow and grow mine until planting out,  like this, in an old cat litter tray
http://chat.allotment-garden.org/index.php?topic=69457.msg879457#msg879457

my tray was an old one (well washed!) and I've never been successful with growing pencils, they just never grow to leek size as they should   

I normally transplant at the crook stage for leeks and onions into three inch pots but its only for the show plants if you are just growing for the table leave them in the tray and plant out from it however they will take a check because you will disturbe/damage the root system when you take them out of the tray. once the seedlings are through move them to somewhere cool and light but frost free.

That's MY photo! 

Plagiarism, that's what it is!

Full thread on it here from the FAQ's section.

http://chat.allotment-garden.org/index.php?topic=26363.0

Worth a read down the section - there's a lot of info that will answer a lot of questions that may pop up in the next few months, once we get under way.

They are - they're the current crop.

They were attacked by leek moth earlier in the year, but have managed to grow though it. That' something you'll have to look out for this year, as it's reached our neck of the woods.