Do not plant black walnuts, eastern red cedars, junipers, and hawthorns near apple trees. Avoid planting tomatoes, potatoes, peppers, brassicas, and root vegetables near apples. Sunflowers nearby also ...
A hawthorn tree with many red "haw apples" as they appear in October. Note the small, apple-like fruits. Also note the curled leaves and the long thorns on the branches.