Q: My fall-planted Fire Power nandina didn’t turn red this winter. They’re in full sun and the soil looks good. Any ideas? John Payne, email

A: Probably the plants are just too young to color up very well. It takes a year for any planted shrub to grow vigorous roots. Without good roots, a ‘Fire Power’ nandina can’t supply the nutrients that make up the photosynthetic pigments that turn the leaves brilliant red.