When planting watermelon you can plant seeds or transplants – just be careful with transplants as watermelons have sensitive roots. Look for transplants grown in peat pots that can be planted straight into the ground; this can help prevent stress to the young roots. Plant your watermelons in a location where they will receive full sun. Watermelon is versatile and it will grow in almost any type of soil as long as it’s well-drained. Your seed package should have the exact spacing needs for your particular variety. A good rule of thumb is that plants should be spaced 36 inches in rows 7 to 8 feet apart.
Watermelon plants grow best when temperatures during the day are between 70 and 85 degrees Fahrenheit, although they can handle daytime temperatures up to 90 degrees. With this in mind, the best time to plant watermelon will depend on where you are in the state. In North Florida you can plant watermelon in March and April and again in July and August.
There are a few varieties of watermelon that do particularly well in Florida. If you are planning to grow the popular icebox-sized watermelons, look for ‘Sugar Baby’ or ‘Mickeylee’ varieties. If you have the space and desire to grow larger watermelons look for ‘Jubilee’ (Florida Giant), ‘Crimson Sweet’, or ‘Charleston Grey 133’.
Watermelons take about 90 days to mature depending on the variety. It can be difficult to know when your watermelon is ready to harvest. Look for the bottom of the melon to be cream-colored or bright yellow; a white or pale green spot means the melon is not yet ripe. Check the curled tendril closest to the melon on the vine – when it turns brown and shrivels, the melon should be ripe. Harvested watermelons typically last one week when stored at room temperature, two weeks when refrigerated.