Melons like hot weather. You have to make them think they are growing in the Honduras. When their roots get cool nights they slow their growth. Sounds like you have good rich fluffy soil. Add some Bone Meal to it. Mix it in good. Get some white plastic and lay it on the bed, a good large area. They are going to be growing bigger and longer than you've ever grown them.
Hang on, getting a second cup of coffee...
Lay that plastic good with the edges tucked into the ground at the edges. You'll be using 2x6 wood to get in there to put the plants in so you don't unfluff your fluffed up soil with the plastic over it. So it's going to be a bit of gymnastics.
Have a pair of garden scissors to cut good sized X's where you put the plants in. After making the X, cut the inner points of each X off so the plastic does not touch the main stem of the plant. Nearby each X slice up some watering holes and press them down some and stick a stone or something there so water can get in. As you put the plant in, tuck the rest of the inner point of each X cut in. (In a month or so you'll slice them open some more.)
If you really want to go for fooling those plants even more, to the north you can make a reflecting fence 2 or 3 feet high with more white plastic on the face of it.
The north wall of my garden is done like that. Actually, thank you for reminding me. I have to repair mine up some. Been putting that off. White plastic begins to degrade in a year unless it is high quality greenhouse plastic. For purposes like this, my white plastic is the kind painters use, a heavy grade, but it is not uv resistant. That's ok, just needs replacing sometimes.
Another thing:
Some varieties are more suited to grow in northern conditions than others. For Watermelons, I found while living in Montana that SWEET SIBERIAN does not need such extreme warmth for the roots to grow. For Cantaloupes, a hybrid called EARLIDEW also does not need such extreme heat for her roots.
Most any zone 7 has plenty of season for even almost the longest to mature melon. That is not the limiting factor. So, there is no reason to try to put them in extra early. Melons really should go into the garden a week or two AFTER one would put Tomatoes into the garden in zones 6, 7, and 8. That's my guess.
Those long to mature varieties will be wanting it to be still hot when they mature, and it might not still be hot in zone 7 for them, but the early to midearly varieties, it will still be hot enough for them when they finish.
THE FINISH: As the melons are ripening you want the sugars to develop and remain in the melons. Too much water seems to dilute the sugars, so watering gets reduced starting the last 3 weeks, less and less water, to I guess almost none the last 5 days or so.
Melons are a true test! Grow good melons and you are a master gardener!
JackB's little granddaughter is growing melons this year with Jack's help. Isn't that cool? Little 5 year old girl growing sweet n early cantaloupes!
I'm using raised beds with top soil mixed with composed manure, compost, vermiculite, nursery growing mix. I don't know what I'm doing wrong but I have about 20-30 seedlings that I need to get in the ground soon. Any helpful hints about growing melons in this area? I also just built a greenhouse that has a raised bed on the southern wall if that would be a good option.
