In the state of Colorado within the United States, what variety and/or cultivar of watermelon does best in urban vegtable gardens? Given that the word "best" is subjective, I will note that the objective consideration here is than more than half of the fruit ripen before September 18th.
If you wait too long, the first frost of fall will freeze the watermelon and make them mushy. The melon will not be ripe and ready to eat.
In Aurora, Colorado I have grown different watermelons and a variety known as Diana watermelon had almost all of its fruit ripen before the first snow or a night with freezing tempuratures.
The bigger a watermelon is, the more time it takes to ripen. I reccomend that you not grow watermelons if the photograph on the website, or photograph on the seed packet shows a big melon.
Most watermelons in Colorado grocery stores are too big to grow in Colorado. Small fruit taste just as good and get ripe faster than big ones.
I reccomend the variety named Diana, but you can also search for "ice box watermelons".
The outside of a Diana water melon is yellow colored, which is strange, but the part most people like the taste of is the usual red color.
In Colorado, plant watermelon after May 13th. Roughly 3 months after you plant the seeds, the fruit will be ready to eat.