Nandina is such a great shrub and if you are planting the Nandina at the end of summer, I recommend no fertilizer when you transplant them into the garden. This is because winter is coming and you want these shrubs to slip into dormancy so they will be better protected from the coming cold and not push out new growth. Then in the spring you can sprinkle a slow release all purpose plant food such as Osmocote around the base of the shrubs. Most trees and shrubs do not need additional fertilizer once established and do not need fertilizer every year. Too much fast growth is weaker and more prone to insects and disease. An organic mulch on top of the soil such as bark or wood chips is the best way to pamper the plants as a mulch will help to seal in moisture, keep out weeds and level the soil tempertures. Keep growing, Marianne Binetti