A long growing season (at least 3 months of warm weather) is needed to mature and develop sweet watermelons. In short summer areas, a warm indoor start can count towards the long-season requirements. If you live in the North, starting your watermelon seeds indoors 2-4 weeks before your last frost date will allow you to take advantage of any warm, sunny days outdoors and still be able to bring them in at night or on cooler days. Planting too early will cause the plants to develop tendrils or more than four leaves which may cause your plants to have difficulty setting roots once they are transplanted to the garden. In the warmer southern climates, watermelons can be direct-seeded in the garden once soil temperatures have reached a steady 75-80F.

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