About Yellow Crimson Watermelon: The heirloom watermelon Yellow Crimson is nearly identical to the red-fleshed Crimson Sweet. Rather than being the result of hybrids, yellow and white varieties of watermelon are actually more ancient than their pink and red counterparts. Historians believe that the yellow versions grew wild in South Africa originally.
Yellow Crimson Watermelon Germination: In cool climates, watermelon seeds should be started indoors, but no sooner than a month before transplanting; plant three seeds per peat pot, 1/4" deep. Provide heat to keep the soil at least 80-85 degrees F. Cut off all but the strongest seedling as soon as true leaves appear, and transplant about a week after frost; put two or three plants in each hill with a 6-8' space in all directions. Gardeners in warm climates will be able to direct sow watermelons as soon as the soil temperature reaches at least 75 degrees F, planting six seeds per hill with 6-8' of space in all directions. Thin to the strongest two or three plants as soon as the seedlings appear. Watermelons should be planted in full sun and rich, loose soil. Young seedlings may benefit from black plastic to warm up the soil.
Growing Yellow Crimson Watermelon Seeds: As soon as the vines begin to develop, apply a thick layer of mulch to control weeds and protect the melons from soil contact. Keep the soil moist until the fruit begins to grow, then water only if the soil dries out completely. Watch out for insect pests, which can be a problem.
Harvesting Yellow Crimson Watermelon: Gardeners use many different methods of testing whether their watermelons are ripe, but knowing the approximate mature size of the melon helps to determine when it is nearing ripeness. One test is to knock on the watermelon with your knuckles, listening for a dull thump rather than a hollow ring. Another method is to check the underside of the melon where it rests on the ground; the skin should be a rich yellow. Also, the curling tendril closest to the stem of the melon often indicates ripeness when it begins to turn brown. Watermelons usually keep for several weeks in a cool place.
Saving Yellow Crimson Watermelon Seeds: Watermelons will cross with other varieties of watermelon, so isolation may be necessary to ensure genetic purity. When the melon is ripe, the seeds will be mature. Cut open the melon and remove the seeds; wash them to remove the sticky residue. Spread them out to dry for a week, then store them in a cool place for up to four years.
Detailed Yellow Crimson Watermelon Info: Citrullus lanatus. Annual. 80 days. 750 seeds per oz. 6-12" height. 5-6' spacing. Produces round 10-15 lb. green striped watermelons with yellow flesh.