I have good luck planting Cooperstown seedless watermelon. I use 3 different seeded for pollinators. I use one of the covered 4 shelf $30 green houses in my house with grow lights and a heater in it. The seedless watermelons will germinate in about 6 days if you maintain 90 degrees in it. Once they pop up its out to the green house outside for the natural light. I keep the outside green house 60 degrees at night. One thing I have learned to do is I use the 3 inch jiffy pots. I have had the plants over 4 foot long before transplanting. I just tear the bottom off the jiffy cup and have a 3 inch auger for my drill. the roots of the watermelon do not like to be disturbed. I bought my seeds from Osborn seed company online. $25 and you get 110 seeds. I plant 2 Cooperstown and then a seeded watermelon in my rows outside. They need sun all day.