My neighbor told me that butterfly bushes bloom on "new wood". What does that mean? Butterfly bushes flower on the new branches or the "new wood" that will begin growing later in the spring. It means the best time to prune shrubs that bloom on new wood is now, including buddleia or butterfly bush. When you do prune butterfly bushes, it's best to cut them to the ground.
Many of the shrubs in our landscapes bloom on "old wood". Old wood refers to last season's growth. These shrubs flower in spring and early summer and soon after flowering, they begin to set the buds for next season's blooms.th e time to prune ornamental shrubs that flower in spring and early summer, is right after they bloom. Forsythia, lilac, ninebark and weigela are common shrubs in the area that need to be pruned after they bloom. You'll have about a month to prune these spring and early summer flowering ornamentals. After you're done pruning, feed your shrubs an 11-15-11 fertilizer. Pruning and feeding within a month of blooming will help your shrubs set bud for next years flowering season.