Mountain Valley Seed Company Black Diamond Watermelon Seeds

While you can direct sow them in very warm climates, starting these seeds indoors is recommended. Because Black Diamond watermelons require a long growing season, starting them inside a few weeks before your last frost date gives them the head start they need to mature properly.

These are vigorous growers that need plenty of room to spread. Plan for at least 6 to 8 feet of space between plants if you are planting them in rows, or ensure your garden bed is large enough to accommodate their sprawling vines.

Generally, no. Black Diamond is a large, heavy variety that produces substantial fruit, making it difficult to support in standard containers. They perform best when planted directly in the ground or in very large raised beds with ample soil depth.

Open-pollinated means that if you let the fruit fully ripen and save the seeds, the next generation of plants will grow true to the parent variety. This allows you to save seeds from your best melons to plant again next season, unlike hybrid varieties which may not produce consistent results.

Look for the field spot—the area where the melon rests on the ground—to turn from a pale white to a creamy yellow. Additionally, the curly tendril closest to the stem should be brown and dried up, which is a reliable indicator that the fruit has reached peak ripeness.