When growingblackdiamondwatermelons, be vigilant for the most common pests including melon aphids, cucumber beetles, squash bugs, and squash vine borers. when to harvest the blackdiamondwatermelon!Laws of Gardening5.6K views • 2 years agoLivePlaylist ()Mix (50+). 6 WatermelonGrowing Mistakes To Avoid Epic Gardening1.3M views • 4 years agoLivePlaylist ()Mix (50+). How to GrowBlackDiamondWatermelon From Seed#. These juicy melons take some time to mature, so it is best to start seeds indoors about one month before the last frost. Here’s how: For areas with long, hot growing seasons, these melons can be planted directly into the garden. Discover essential tips for growingBlackDiamondwatermelon and explore the inside of this unique fruit. GrowingBlackDiamondwatermelon plants is very similar to growing other varieties. Since all watermelon plants thrive in sunny locations, at least 6-8 hours of sun each day is imperative. BlackDiamondWatermelon is large melon with a glossy solid black-green rind with deep red, tender, crisp, sweet flesh and large grayish black seeds, weighing 40-45 lbs.Growing Ideal pH: 6.0-6.8. Choose a warm, well-drained soil for BlackDiamondWatermelon. Blackdiamond routinely produces watermelons in the 50 pound range, but some can grow as large as 75 pounds!Growing Conditions Outdoor. Harvest Advantages Slicing. About Watermelon Seeds - BlackDiamond. Citrullus lanatus. Seed Type Heirloom Seed, Open Pollinated Seed. BlackDiamondWatermelon is sometimes described as the 'king' of the garden, sometimes weighing 50 pounds or more. The bright red flesh is noted for its juiciness and sweet taste. The blackdiamondwatermelon is an heirloom variety falling under the open-pollinated category. The plant grows on vigorous vine borers to yield a fruit size that weighs up to 50 pounds. Like all watermelons, the BlackDiamond is grown as an annual.Because the water content of watermelons is over 90 percent, these fruits also require consistent moisture until the fruit is set. BlackDiamondwatermelonsgrow best in full sun, which means six hours a day.