From The Bedford Extension MG Help Desk

QUESTION

Client wants to know whether hydrangea, azalea & miscellaneous shrubs can be pruned in the late Fall.

DIAGNOSIS / RECOMMENDATION

According to Virginia Cooperative Extension (VCE) publication A Guide to Successful Pruning: Shrub Pruning Calendar (pub #430-462) there are a number of shrubs that are listed in the ‘can be pruned in November / December.’ However, Azalea and Hydrangea are not in that list. Azaleas, both deciduous and evergreen, bloom on last season’s wood; thus pruning them while dormant will reduce the number of blooms for next year. The best time to prune azalea is May, June, and July. On evergreen azalea, specifically, if shrubs have azalea caterpillar or galls, pruning in spring/summer is advised to remove these pests.

ADDITIONAL INFORMATION

The general rule is that spring-flowering shrubs flower on one-year old wood, so these should not be pruned until after they finish flowering. Shrubs that flower in summer or the fall flower on new wood, and can be pruned earlier in the year (before bud set) or immediately after bloom (1, 2). Removal of dead or damaged plant parts can be done anytime of the year. It is important to use the proper tools and remove plant material in the proper way to keep the plants healthy and avoid transmitting disease from one plant to another (2, 3). Evergreens such as hollies, boxwoods, cedars, and juniper are also best pruned in the dormant season, roughly November through February (1, 4, 5).

Proper pruning can help keep plants healthy, by improving air flow and removing damaged branches. It can help with the overall appearance of plants. But pruning the wrong time or in the wrong way can result in no bloom, entry for plant diseases and insects, serious plant damage or possible loss of the plant.

RESOURCE LINKS

SOURCE: Betsy Brown, Bedford Extension Master Gardener Volunteer; Help Desk Coordinator