start them early in the house.. so you can get a long enough growing season to actually harvest one ... lol

ken

Zones don't mean a thing in summer vegetable gardening, since they only refer to the average annual minimum wintertime temperature in an area... BUT your location does mean something. You are probably already aware of the challenges to growing watermelons in your area, I'm guessing they are most likely insufficient heat some summers, and a short growing season.

But to answer your question:
Any of the early-ripening varieties would be worth a try. The most cold-tolerant and early-ripening variety that I know of is called "Blacktail Mountain" and was selected in the mountains of Idaho where the growing season is very short, and the nights average in the 40's. Other good ones to try would be "Crimson Sweet", "Sugar Baby", "Golden Midget", "Orangeglow", and "Cream of Saskatchewan". Don't expect anything near the sizes listed on the seed packets, but it's only the taste that matter anyway.

Crimson Sweet has done well for me in my area. I used to grow sugar baby but found the larger ones did just as well and I preferred their flavor. What I usually do is save seeds when i get a really good watermelon, then plant them in the garden about a week before the last frost date so they don't come up and get frozen (never been successful transplanting a watermelon plant). The watermelon usually ripen in September. Getting a little past the warm season for eating watermelon, but I still eat a LOT of melon in late Sept. and October.

Currently I have a grey stripe like a Charleston Gray (variety unknown, just saved seeds I've been growing for 15 years or so now). They get to 20-25 lbs typically, sometimes over 30. Also a nice big, round, green-white stripe saved from a melon grown in Hermiston, Oregon that ended up in the grocery store a few years ago. Last year a couple of them grew to 30-35 lbs.

Watermelon do like it warm, so plant them on the south side of a building or a protected area where they get full sun. They also don't like being too wet and want to dry out a bit between waterings.

I spent about 25 years in zone 5 (Ottawa, Ontario) and in my experience it was really only the "Yellow Doll" watermelons that were reliable there. Others like "Early Canada" and "Sugar Baby" were okay in a warm summer, but failed otherwise. Yellow Doll were always at least 2 weeks ahead of the pink/red melons... in my opinion the yellows taste even sweeter. I had no problem with the yellow flesh, some people might.

That was a couple decades ago. Newer varieties or climate change/warmer summers might have made a difference since then. I have tried Yellow Doll in zone 3 and got it to full size, but it didn't ripen outdoors and eventually rotted after I brought it indoors when frost threatened.

I ordered some blacktail mountain and crimson sweet seeds. If I actually produce anything great! Otherwise no big deal, I have the space and the time!

Thanks!