Chinese privet is an invasive, non-native shrub first introduced into the U.S. for ornamental plantings. Today, it occupies nearly one million acres of Alabama’s forests with more open areas such as rights-of-way and fields infested as well. Its spread has deteriorated wildlife habitat and reduced forest productivity.
Unlike most other invasive plants, now is the time to start planning to control privet. Herbicides are required, and the best time for application is during the cooler months. Mechanical removal (cutting, brush grinding, etc.) does not offer satisfactory control on its own because of vigorous resprouting, but can facilitate the application of herbicides. There are three types of herbicide application that are effective on privet: foliar, cut stump, and basal bark.
For foliar applications, use a concentrated glyphosate product with at least 41 percent active ingredient. Mix the product with water to produce a 4 percent solution (5oz/gal). Glyphosate is the active ingredient in Roundup, but is now sold under many different brand names. As with all other herbicides, the active ingredient is what matters, not the brand name. Cheaper prices can often be found at local farm centers, co-ops, etc. Applications should be made during late fall and early winter when daytime temperatures are 50-60°F. Because privet is an evergreen, foliar applications can be made when most other plants are dormant, thereby reducing the risk of injuring surrounding vegetation. More importantly, spring and summer applications are not as effective. Coverage of all the foliage, especially the top of the plant, is critical. If the privet is too tall to accomplish this, use one of the other two methods.
Cut stump applications can be made with glyphosate as well. Mix the product to produce a 25 percent solution (32oz/gal). Cut the stems low to the ground and immediately (within 30 seconds) apply the solution to the stump surface. Late fall is the best time to use this method.
For basal bark treatments, use the oil-soluble herbicide triclopyr ester, the active ingredient in the concentrated product Garlon 4 and the ready-to-use Pathfinder. These products may be difficult to locate, but can be ordered if not stocked at a store near you. If using the concentrate, mix the product with an oil carrier to produce a 20 percent solution (26oz/gal). Spray the entire circumference of the bottom 12-15 inches of stems. Applications should be made during cool weather when daytime temperatures are below 80°F. If applied at warmer temperatures, the herbicide can volatize (turn into a gas) and injure surrounding vegetation. It may take several months to fully work, but this is a very effective treatment.
Regardless of the treatment used, follow-up is required. Inevitably, a few resprouts will occur. Foliar spot herbicide treatment is the easiest follow-up approach. It is absolutely critical to do follow-up control. Otherwise, privet will rapidly reinfest the site and the initial treatment investment will be lost.
For more information about privet or other topics related to forestry, wildlife or natural resources please contact Regional Extension Agent, Patrick Cook, at the St. Clair County Extension office at (205) 338-9416 or email at email@example.com.