Watermelons have male and female flowers. The male flowers have a stamen in the center with a sort of wavy anther at the top which holds the yellow powdery pollen. Female flowers have a center piece, the top of which is called a stigma; you should see a small swelling at the base of the flower where the fruit will form once pollinated (males do not have this—they have just plain straight stems). Select a male flower whose anther is full of mature yellow pollen. Dab a small, dry paintbrush (or a cotton swab) against the anther to get some pollen onto the brush. Then brush the paintbrush against the stigma of a female flower that is fully open and at peak. Some gardeners instead like to snip off the male flower, remove its petals (male only), and then dust pollen onto the female flower directly with the male flower; one male flower can pollinate about 3 or 4 female flowers. Keep in mind that male flowers sometimes open a little earlier in the growing season than female flowers. Also, each female flower is open for only one day, so you need to keep an eye out for them. Hand pollinate in the morning for best success. Good luck!
Watermelons have male and female flowers. The male flowers have a stamen in the center with a sort of wavy anther at the top which holds the yellow powdery pollen. Female flowers have a center piece, the top of which is called a stigma; you should see a small swelling at the base of the flower where the fruit will form once pollinated (males do not have this—they have just plain straight stems). Select a male flower whose anther is full of mature yellow pollen. Dab a small, dry paintbrush (or a cotton swab) against the anther to get some pollen onto the brush. Then brush the paintbrush against the stigma of a female flower that is fully open and at peak. Some gardeners instead like to snip off the male flower, remove its petals (male only), and then dust pollen onto the female flower directly with the male flower; one male flower can pollinate about 3 or 4 female flowers. Keep in mind that male flowers sometimes open a little earlier in the growing season than female flowers. Also, each female flower is open for only one day, so you need to keep an eye out for them. Hand pollinate in the morning for best success. Good luck!