Pruning Rhododendrons and Azaleas
Some thoughts and suggestions in regard to rejuvenating old plants and old gardens
by John M. Hammond
Contents:
- 1. Introduction
- 2. Getting the Pruning Time Right
- 3. Pruning Evergreen Azaleas
- 4. Pruning Deciduous Azaleas
- 5. Pruning Rhododendrons
- 6. Pruning Methodology: Some General Notes
Introduction:
Probably the most frequently asked question asked at the Display & Information Stand at the Gardening Scotland Show’s has been ‘Can I prune my Rhododendrons and Azaleas and, if so, how do I do this ?’ There are also some parallels to be drawn with newer members, or enquiries from gardeners on older estates, who tend to ask similar questions relating to old collections of Rhododendrons along the main drive or in the woodlands. Of necessity, questions of this type usually receive a somewhat guarded response, something along the lines of ‘Yes, rhododendrons and azaleas can be pruned, but with some care. But, why do they need to be pruned in the first place?’ To my mind this latter part of the response is absolutely crucial. As with most queries relating to horticulture, there is a need to understand the circumstances that have led to the need for advice to be sought. Only then can an adequate and viable response be given.
Once a dialogue has been opened up with the person concerned a clearer picture often emerges, but the reasons given for pruning can be very diverse and despite the passing years I am still sometimes bemused by what I am told. The straightforward reasons are easily dealt with, be it that the plant has grown too large, or the gardener wishes to save the plant’s beautiful display of flowers whilst cutting it back. Perhaps the person may have recently acquired a new home with a mature garden containing a selection of rhododendrons that have not received any attention for many years, or maybe the owner wishes to sort out a collection of plants that have outgrown their location.
But in contrast, there is the gardener who has been advised that it is necessary to prune rhododendrons and azaleas on a regular basis, or wants to cut back the large plants along both sides of the drive without losing any flowers prior to putting the property on the market. Or maybe the person has heard that all the plants can be rejuvenated by cutting them back to the ground. All these queries can be answered with a bit of care but, unfortunately, there is little that can be done to help some owners in the latter category who have cut back their plants back to the ground prior asking the question at the Show! Sadly, instances of this situation are far more prevalent than would be supposed.
So where do we start? Perhaps the best place to begin is to discuss the timing of pruning work. We can then follow this by outlining the way of approach to pruning azaleas as they tend to generate the highest number of queries, after which we can build on this foundation and discuss some aspects relating to rhododendrons.