Done a little research and thought I would post here for some Alaskan input.
I started my pumpkins (sugar) inside in April and transplanted them a couple of weeks ago. They are about 10" high and wide with buds and vines starting to develop. They also have pale leaves, with some of the first leaves (real leaves) yellowing. I have watered them with compost tea and also mixed in some compost when they were transplanted.
They were grown in peat pots (which I kept in plastic bags to soften them/keep them moist, so the plants wouldn't get root bound). When I transplanted the roots were coming through the peat pot walls pretty well. However I do wonder if some of the issue I am seeing is a result of being root bound?
Also - possibly need some commercial type fertilizer?
Last year I planted the pumpkins in a new bed that was a 50% compost/50% garden soil mix. They did awesome. So I am thinking perhaps the issue is that they need more nutrients where they are planted this year.
Also considering putting a 'hot house' around them - perhaps the cool nights are not easy on them?