Pruning Modern Landscape Plants
By Todd Layt
Pruning ideas including utilizing modern machinery for efficient pruning
Whether it’s a tree, a shrub, a ground cover, a grass or strappy leaf plant, pruning is eventually required for all in an ornamental landscape. Modern landscape plants have been bred for less pruning, but with modern equipment should we really be pruning less? What are the best techniques and equipment for each plant category? This issue we look at ground covers, shrubs, grasses and strappy leaf plants. Next issue we look at tree pruning including coppicing.
Working our way up from ground covers to small trees, our modern ground covers are often more dense than landscape ground covers of the past. Breeders over the last 20 years have released many plants with shorter internodes. Grevillea groundcovers have become more prostrate, and there are now even dense prostrate Westringia ground covers. More prostrate will mean less vertical pruning, but keep an eye on the spread of these modern ground covers. Keeping them regularly in check by edging there lateral growth is essential, but with modern pruning equipment’s increased efficiency and ease of use why stop there. More frequent top pruning will result in tidier plants. Some groundcovers benefit from running a mower or brush cutter over them once a year.
In the USA in Texas, you can drive through suburbs in winter and see most of the Liriope, Mondo, and vine type plants like Asian Jasmine cut back with a lawn mower or brush cutter. Soon after in mid spring drive by and you will see vibrant clean foliage ground covers throughout Texas. Maybe it’s time for Australian maintenance companies to consider similar techniques. Vines particularly left unpruned for many years generally become unattractive. They may harbor wasps and rodents, experience foliage and branch dieback, and lose their landscape effectiveness. Prune out the top one-third of overgrown or elongated stems. Prune old mature stems that are declining in vigour by one-third or even more. Winter is the best time. Make sure the mower or brush cutter blades are sharp.
On the other hand, many modern ground cover plants may not require regular pruning to survive or to look reasonable, but to look spectacular or to achieve a more formal look, light pruning 4 to 6 times per year can produce amazing results. A couple of examples explain best. Grevillea juniperina or the popular Westringia groundcover Mundi can be pruned once per year for a native finish, or pruned 4 to 6 times per year for a tidy modern clean finish. In summer if you prune every month and a half, the finish is amazing, akin to a manicured lawn. Treat these natives like some exotics, and you get a more formal finish. Never prune back hard in summer as this can hurt the plant, but regular light tip pruning can be done year round in most parts of Australia. These days an argument could be made that regular light pruning with quick efficient machinery is just like regularly mowing the lawn.