I live just west of St. Louis, MO and just about everyone I know has problems growing watermelons. Our soil has quite a bit of clay, so I have mixed in sand and peat but the results are the same (i. e.the melons grow a little larger than grapefruit size then they turn black on the end and rot). Any ideas? Am I not watering enough? Not enough of a certain mineral? Please help.
Certified GKH Gardening Expert
This is blossom end rot and it is caused by a lack of calcium in the plant. But, it is normally not caused by a lack of calcium in the soil, but rather the inability of the plant to take up enough calcium from the soil to support the fruit.
This article is about squash and blossom end rot, but squash and melons grow very similarly, so this article will help you with your melon problem: