Watermelon leaves have a sticky substance and now the melons do. What's going on?
Sticky Leaves and Now Sticky Melons
Certified GKH Gardening Expert
Sounds like you have an insect infestation, possibly aphids, which secrete a sticky substance called honeydew. Treat the plants with neem oil to eradicate whatever pest is affecting them. This is both an effective treatment and safe. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm