If you are lucky enough to have a garden that supports the glorious rhododendron (Rhododendron spp.), you know these bushes deliver on gorgeous blooms for months at a time in the spring and early summer. Healthy rhododendrons don’t require lots of cutting to thrive, but some careful pruning can enhance the shape of these woody plants and maximize blooms. The mistakes to avoid while pruning, however, include doing so at the wrong time of year. Be careful about breaking out those shears and saws at the first signs of spring, or you might be cutting off your chances for vigorous blooms in the future.

Pruning a rhododendron too early will remove flower buds before they have a chance to develop. Rhododendrons form buds soon after they are finished blooming, and those new buds last through the winter to produce next year’s spring flowers. If you do choose to prune, wait until just after flowering is wrapped up, which for your USDA growing zone might be late spring to early summer. As blooms fade during the spring growing season, it is fine to dead-head old blooms, as it encourages the formation of new buds later on. But poorly-timed pruning of a healthy plant will not only prevent future flowers, it can also weaken the plant’s ability to fight off disease. 

There are few circumstances that might make spring pruning a good choice. Formative pruning in the first spring or two after planting will form stockier bushes in future years, even though you will be sacrificing that year’s blossoms. For this type of pruning, pinch off new flower buds and lop off the ends of new shoots on a young plant. This practice will encourage new branching and more bud formation.

For an older bush that has become leggy, has become overwhelmed with blooms, or has gotten too large for your space, a vigorous pruning done in early spring can revitalize your plant. Don’t be afraid to get tough with this type of rejuvenation pruning for your rhododendrons – even taking the plant down close to its base.

Another time that spring pruning might be on the menu is if you plan to relocate your rhododendron to another spot in your landscape, or even to a new home. Early spring (while temperatures are still cold) is a good time to consider a move. Pruning back some branches will not only make transporting the bush easier, it will ease the impacts caused when you cut the plant’s roots for the move. Again, while you may be sacrificing some blooms for the coming season, this type of spring pruning will set your rhododendron up for success for years to come.