When to Prune Flowering Shrubs

By Dr. Douglas F. Welsh, Landscape Horticulturist

f a shrub is grown for its flowers, time the pruning to minimize disruption of blooming. Spring-flowering shrubs bloom on last season's growth and should be pruned soon after they bloom. This allows for vigorous summertime growth and results in plenty of flower buds the following year. Some examples of shrubs that bloom on last seasons's growth are:

Cercis canadensis - Redbud
Chaenomeles japonica - Japanese Quince
Chionanthus virginicus - Fringe Tree
Forsythia spp. - all Forsythia species
Lonicera spp. - Honeysuckle
Raphiolepis indica - Indian Hawthorn
Rhododendron spp. - Azaleas & Rhododendrons
Rosa spp. - Rambling Rose species
Spiraea spp. - early white Spirea species
Viburnum spp. - Viburnum species

Some shrubs that bloom after June usually do so from buds which are formed on shoots that grow the same spring. These shrubs should be pruned in late winter to promote vigorous shoot growth in spring. Examples of shrubs that bloom on current season's growth include:

Abelia X. grandiflora - glossy Abelia
Buddleia davidii or B. globose - Butterfly Bush
Hibiscus syriacus - Shrub Althea
Hydrangea arborescens - Hills of Snow
Hypericum spp. - Saint-Johns-wort
Lagerstroemia indica - Crape Myrtle
Rosa spp. - Bush Rose
Vitex agnus-castus - Chaste Tree

For complete information on pruning shrubs, consult our website:

www//aggie.horticulture.tamu.edu