Like most homeowners, you probably use weedkiller around the house. Be very careful where you spray it, and how much you use.
Heidi Kratsch, a Utah State University Extension ornamental horticulture specialist, says that applied incorrectly or in too high of a dose, glyphosate products like Roundup can cause a condition called split bark in woody ornamentals and other woody plants. When sprayed too close to non targeted plants, the tree or woody plant absorbs the chemical through it's roots, the chemical breaks down the bark structure and destroys the winter hardiness of the plant. This causes freeze/thaw damage, which in turn can cause sunscald. The cosmetic damage is bad enough, but for nursery owners, this makes the plant unsalable.
The news is not all bad. It is not the glyphosate itself that causes the damage, but the surfactant, or wetting agent, in some products. The surfactant helps spread the chemical and help the chemical cling to the targeted plants leaves so the glyphosate can be absorbed. Read the label when you purchase a weed killing product. On the label, look for the words "adjuvant load", this is the surfactant. The following products do not contain a surfactant: Campaign, Fallow Star, Glypro, Landmaster BW, Rodeo and Roundup Custom,however, proper use is still needed. What is a safe distance to spray glysphosate from a woody plant? 30 feet is the recommended distance. Glysphosate products should be used as a last resort for combating weeds. Pre-emergent herbicides are a better alternative, but need to be used prior to a weed seeds germination. According to Kratsch and Salt Lake County Extension horticulturist, Maggie Shao, the following woody plants are most susceptible to glyphosate:
All herbicides have risks, but used correctly, can be a great tool in a gardener's arsenal to control those nasty weeds.
Dwayne Haskell owns and operates Mistkits.com where complete misting kits, individual components, and advice can be found. After building his own misting system for his nursery, he realized he could design and build systems for small nurseries or home gardeners who are interested in starting their own plants from cuttings.
He has written an E-book titled Build an Arbor in Just One Weekend, and another on gardening, landscaping and plant propagation tips. He also enjoys teaching others how to grow their own landscape plants and owns and moderates the Mistkits blog, where you can find more articles, polls, and quizzes on landscape and gardening related topics. Be sure to grab your own copy of an E-book when you visit!