How Plant Growth Regulators Make Landscaping Easier

If you haven’t already, you should consider adding plant growth regulators (PGRs) to your arsenal of tools this season when dealing with landscapes and maintenance. As the name implies, they help regulate plant growth, but they have multiple benefits. Specifically, PGRs divert the plant’s energy towards growing bigger, stronger roots with more fine root hairs and away from development of leaves and branches. The increased root growth means plants can uptake more water and nutrients. The leaf structure changes to be thicker with smaller stomata, which can result in reduced water vapor loss and disease and pest resistance. Slower branch growth means less work trimming and shaping branches and leaves!

We have very specific aesthetic needs when it comes to flowering shrubs and other flowering plants. We want just the right colors and high numbers of blooms, the flowers placed just so. Not too tall, branches not too leggy, and dense enough flowers and leaves giving the right burst of color. While you could trim, cut, and shape flowering shrubs until they’re just right, that can be imprecise and takes a lot of work and upkeep. A plant growth regulator will help achieve those ideal results and save time and labor. In a tight labor market like this one, that’s incredibly valuable.

Below is a journey of two different groups of lilac shrubs. One group was an untreated control, and the other was treated with a foliar spray of the plant growth regulator Shortstop 2SC. See the difference for yourself!

In April 2021, you can see some difference between the treated and untreated lilacs. Although the buds are just starting to develop, you can see the leaves on the sprayed bush (right) are closer together than the ones on the control (left). We let the shrubs develop for another year before checking in again.

resized lilacs come on

In Spring 2022 there is a very noticeable difference between these two shrubs. The untreated plant is over 6 feet tall, with widely spaced leaves and bud. Not only is it less attractive, but it would take much more work to shape it to something a customer might want. The treated tree has a denser and more attractive form.

Untreated lilac bushes in their natural state
Untreated lilac bushes in their natural state

The benefits to the plant, the applicator, and the property owner are numerous. Besides better visuals, the denser greener leaves are more resistant to pests and leaf diseases, which means less time spent on pesticide treatments. Treated plants will require fewer visits for shrub maintenance and upkeep, which should keep customers happy. There won’t be as much need to trim unruly branches back and hope the plant will still look good. And it’s overall less work for service providers. Win, win, win.

Anytime during the growing season is a good time to apply plant growth regulators, as long as you prune the shrubs first. Consider using them to reduce your workload in future seasons!