Terran's Tips

Tree Growth Regulators: Growth Control for Trees

This month's Tree Tip was written and researched by Britt Hubbard, Director of Plant Health Care and ISA Certified Arborist #SO-5792A. He may be contacted directly via email with any questions concerning this article or any tree related issues.

Is your backyard oak starting to shade your swimming pool and deck? Are the street trees in your median looking stressed? Is your magnolia approaching utility lines? Are you looking to save a tree before construction begins on your property? These are all legitimate questions about trees in your landscape that can be addressed by Tree Growth Regulators (TGRs). 

While trimming and pruning are the main method used to manage tree and shrub size, TGRs are another excellent tool arborists use to control growth in trees and shrubs.  TGRs also contribute multiple unique benefits that reduce stress on trees in the urban environment.

TGRs are growth inhibitors that are applied to the soil and taken up by the plant’s root system.  Once in the plant, TGRs inhibit plant growth by 85-90%. In most trees and shrubs, a single treatment lasts for three years.  The reduction translates to trees and shrubs that would normally grow 2-3 feet per year, to now only growing 3-4 inches per year.  If you extrapolate that out to three years of growth, trees that would grow 6-9 feet in three years now only grow 9-12 inches in three years. The growth control reduces maintenance needs for trees and shrubs that are just the right size for their space. 

The tremendous reduction in growth has many uses including:

  • Growth control of trees and shrubs in crowded landscapes
  • Growth control of trees that may shade pools or decks
  • Preventing trees on golf courses from overgrowing and shading greens
  • Growth Control of trees on commercial properties, and
  • Growth Control for Right-of-Way maintenance

On treated plants, energy normally used for plant growth is redirected from shoot growth to root hair growth (increasing the plants ability to take up water and nutrients), chlorophyll production (increasing capacity for energy production), and pest defense (increasing the plants ability to defend against disease and insect attacks).   These benefits expand the applications of TGRs beyond growth control. 

With these benefits in mind, TGRs can also be used to:

  • Help declining oaks and other large trees recover
  • Treat trees before or after construction activities to reduce stress
  • Reduce stresses and increase life-span of street trees
  • Increase the life-span of trees grown in large planters

TGRs offer management solutions to many tree and shrub issues in the home landscape, on the golf course, in HOA common areas, on commercial properties, municipal properties, and more.  The arborists at Woodland Tree Service can determine if TGRs are appropriate for your needs. 

Call (901) 309-6779 or email us at info@woodlandtree.com to set a meeting with our arborists today.

Posted by Mark Allen at 13:31