Decide whether to plant watermelon seeds or transplants. Watermelon seeds need to germinate at a temperature over 70 degrees. If you live in a cool climate, it might make sense to start them indoors a few weeks before the last frost, so you’ll be able get the seedlings underway at the beginning of the growing season. Otherwise, plan to plant the seeds directly in the ground well after the last frost, when the temperature is holding steady at above 70 degrees. Watermelon seeds and transplants are available at nurseries in early spring.
Watermelons like loamy, fertile, well-drained soil. To determine whether your soil gets good enough drainage, take a look at it after a heavy rain. If you see puddles in the dirt, the soil isn’t draining well enough. To further enrich the soil, till compost into the top of layers. [2] X Research source Watermelons grow best in soil with a pH of 6. 0 to 6. 8. Test the pH of your soil and determine whether the levels are appropriate for watermelon plants. If not, you can change the balance by adding compounds available for purchase at a plant nursery.
When the seedlings grow, thin to the two strongest, to give the strong one room to grow. Don’t let the soil dry out; you should water at least once daily.
Another option is to lay black landscaping fabric or plastic cloth down after you have made the hills, and then cut holes on top of each hill where you will plant seeds. You can also lay mulch on top of the cloth. This method helps to retain soil moisture and keep weed pressure down.
Keep the foliage and fruit dry. You can place fruit onto a clean piece of wood, large smooth pebble, brick, etc. On very hot days, the leaves will probably wilt even in moist soil. If this limpness can still be seen in the evening after a hot day, water deeply. Sweetness in watermelons can be increased by holding off watering for a week prior to harvesting. However, don’t do this if it causes the vines to wilt. Once that crop is harvested, restore the usual watering to enable the second crop to come through well.
To test the ripeness of a watermelon, thump it. A dull noise sounding back means that it has ripened. Also, check the underside––it is ready when it has turned from white to pale yellow. The curly tendril near the watermelon’s stem should also be dried out when it’s ready to harvest.
