Watermelon loves the sun, so don't plant a culture around trees and shrubs because they make a blackout, and it is highly undesirable for your plants. Also, do not plant melons near some related crops, such as pumpkin, zucchini, and should avoid the neighbourhood of cucumbers. Better put next to corn, herbs (except parsley), spinach.
With melon, you can put those same neighbors, and watermelon. And the watermelon and cantaloupe are the perfect complement and with each other. But keep in mind that gourds grow very much. So next door planted those plants that are early. Thus, you will have time to harvest until the moment when the gourds will occupy a large area. As melon and watermelon do not like overly moist soil, do not plant them next to the strawberries.
Next to the gourd family of plants you can plant black radish. It allocates volatile, which prevents the appearance of spider mites. Neighbors can become the tomatoes they deter aphids, Sawfly and moth.
Pumpkin is very unpretentious. It can be grown directly in the compost heap, these are the conditions for it are ideal. This culture is very late begins to grow, so next you can plant leeks, peas, curly beans or spinach. Highly undesirable planting nearby tomatoes, potatoes and radish, pumpkin can crush crop, and indeed will not grow. Also avoid neighborhood pumpkin with parsley.
Gourds do not tolerate wind, so to keep the gusts, put around the plot of corn, beans or peas. As watermelon, melon and pumpkin absorb from the soil a lot of nutrients, try not to plant them near beets, carrots, garlic and radishes.