Sadly, our garden capabilities where we now live at in the American Redoubt are extremely limited by the growing season. Trying work around.
Almost all crucifers do well in cooler temps , or even short season climates; also, they can be grown in partial shade.
Consider all lettuces, most greens, spinach, peas, beans, and root crops
Also, the use of black plastic will heat up the soil and give you a 10 degree jump, or even use row covers to extend the season longer.
Have you heard of a "Cold Frame", to germinate seeds or extend growing season ?
Well, if you can build a cold frame, then add a hot manure (ie: horse, or chicken) below the base of the cold frame, it will give off heat as the manure oxidizes.
The further below and deeper to the base of the cold frame,.. the less fragrance !
(see below - a forgotten method used by our ancestors)
" How to Use Manure to Turn a Cold Frame into a Hotbed "
http://www.groworganic.com/blogs/articles/use-manure-to-turn-a-cold-frame-into-a-hotbed