My roses have gotten very tall and leggy. Any suggestions to stimulate growth on the lower branches?
This is just a natural growth habit for some rosebushes and there really is nothing one can do to stimulate foliage growth on the canes. Many roses will drop some foliage during the hotter times of the year leaving them leggy. That foliage will usually return once the weather cools again. You might want to consider doing some low growing companion plantings that flower well and add nice color to the lower areas of the leggy rosebushes. Such as some nice Drift Roses, which are a cross between ground cover roses and miniature roses. Or perhaps some Dianthus such as one named Firewitch, as she has wonderful color and fragrance.