I want to know this too! I started leeks from seed again, this time early enough to hopefully get full sized ones instead of the pencil-thin useless things I got the other year. I wonder also when to set them out, and also how much space they need, etc.
I am planning to grow a few in my square foot garden, but most of them out on land with space for everything, in sort of French Intensive beds.

Any advice on leek growing in Maine or comparable climate is welcome

I'm not an expert by any means, but I go by when the night time temps are consistently above 24ºF. Here, thats early April. Some years, I've had the tops brown off from a really hard freeze below 20ºF, but I've never lost any plants.

Thanks for the info. I think grow my onions and leeks indoors for a month and then put them out around the end of March.

MegMaine I am also in Maine! I will be growing onions from seeds for the first time. Haven't tried growing leeks yet but then again this is only my second year vegetable gardening. I would like to hear how it goes and maybe I will try them next year.

Hey to all!I have a Vegetable Planting Guide that came from Wyatt-Quarles Seed CO.in Garner,NC.I live in the foothills of NC which is zone 7.This chart,for my area,says set out onion"sets"from FEB.1-MAR.15 and onion seeds from SEPT.1-30.I get 2 kinds of "sets"-one is for bulb/head type for storage( to keep a while) and the other is spring/scallion type-(they won't keep long)I just planted them last week(FEB.25-26/09) and now,there is 6inches of snow on top!But the onions will be fine!you should be able to get a chart like mine at a local mill,farm feed supply,etc.OR,probably find one online

I don't know if this helps or not but last years leeks that were not dug up are starting to grow now, here in Pa up by the NY state line. Our temps are ranging in the 30-40s daytime and night in the teens. I would say by next month to plant the leeks but keep a clear plastic (large soda bottle with bottom cut out to place over top)just in case! Also all the wild leeks are coming up...it seems way to soon but with the wild and domesticated leeks (and some onions from last year) that its telling me to go ahead for the end of next month.

Hmmm, maybe I should look into growing wild leeks (ramps) since they do well in Maine.
I'm also trying the Winter Sowing method with them and many other things, as a side venture, because if it works well (works even in Canada according to the forum here) I will not need near as much light space for indoor starting next year.

My leek seeds were left over from a couple of years ago, and only a few germinated, but I will try to raise them. I have no idea how people at the Farmer's Market get those massive thick leeks, when all I got were pencil-thin ones after a whole year of trying.

i'm in zone 5b in nw ct and i start my onions from seed on 2/15 and put them out april 15 to 25 depending how lazy i am, the 25th is getting late. last frost date is 5/30 so i go out 6 weeks before last frost date.

tom