It's the time of the year when spending more than an hour in your garden can be unbearable as summer's heat and humidity is finally upon us. The wisest use of this hour for the health of our garden would be spent watering and weeding, which are seemingly the most important garden tasks during the brutal months of June, July, and August here in the South. If you can find the energy and bear the heat a little while longer, summer pruning is one other very important practice that some perennials will really benefit from in the hot and dryer months of the summer.
A proper summer prune can be described most simply as more than a deadheading but far less than a hard winter pruning. The first need to summer prune is to control the height and size of the plant. Certain perennials have been growing strong for 5 months now and can be taller, more spread out, or leggier than we'd like them to be. Cutting them back by a quarter to a third really helps keep the plants contained and from growing into neighboring plants, as well as making the hard winter prune a little bit less complex. Apart from size control, some plants also exhibit some signs of exhaustion at this time of year with yellowing leaves or tips of leaves. Cutting these back also make a garden more aesthetically pleasing.
Vigorous new rose growth after a summer pruning.
As most all of us know, the summers here are hot, humid, and dry. Plants require the most water this time of year, and the infrequent rain isn't enough. Pruning plants back and decreasing their size also decreases each plant's water requirements, as there is less foliage and plant material in need of water, so the same amount of water satisfies the plant far more and goes further.
Much like when we shave or get a haircut, our hair seems to grow back faster, fuller, and healthier. Plants are much the same. A good summer prune helps to refresh a plant and help it come back stronger for the remainder of the growing season, and also aids in more dramatic flushes of blooms in our favorite flowering perennial plants like roses and salvias.
New flush of blooms on a recently pruned rose shrub.
Outside of your weeding and watering duties in your garden this summer, give some of your perennials like knockout roses, salvias, aggressive ornamental grasses, and exhausted crinums a refresher prune. The benefits in the coming months will be worth the extra work and sweat.