The majority of shrubs will survive and even thrive in the garden without supplemental feeding, as long as you’ve chosen types with needs that match the general conditions of your growing location (soil type, water supply, light levels, etc.). That said, feeding can be necessary and beneficial when:
Shrubs have been subject to extreme rainfall or to excess watering in times of natural drought. This stimulates excess growth, which they may not be able to support without the benefit of supplemental feeding, particularly if the water has washed soil nutrients away or disturbed the soil structure.
Shrubs are growing on naturally poor, rocky or sandy soil, particularly if they don’t grow on such soils in their native environment. Well-draining soil is a boon to many shrubs, but it can also be low in nutrients because these are easily washed away.
Shrubs are growing closely together, such as in a hedge, and therefore remain in constant competition for soil nutrients in their vicinity.
The ideal time to feed garden shrubs is just before they begin growing in early spring. Heavy feeders, like roses, can benefit from a follow-up feeding in summer. Flowering shrubs that are regularly trimmed should be fed just after they’re pruned.
Pictured: Kopper King hardy hibiscus.
Learn more about choosing and caring for shrubs, which can make a low-maintenance backbone of any garden design, in Andy McIndoe’s The Creative Shrub Garden.