After Spraying Round Up In An Area Close To My…
Doshia Asked
After spraying Round Up in an area close to my foster hollies, they have started dropping leaves; could it have been the Round Up?
The Gardener’s Answer
Hello, Doshia in Alabama: Herbicide drift can be very harmful, even detrimental, to any plant material that it comes into contact with. This is why it is so important to spray on a calm day so there is no chance of the wind taking the liquid somewhere it was not intended to be sprayed. Even using a piece of cardboard on a non-windy day is a good idea to block potential drift. Other factors also need to be taken into consideration when applying this chemical, including temperature. If the temperature is 85 degrees F or above during or shortly after application, it can cause chemicals to vaporize and move to non-targeted plant material. Glyphosate is the active ingredient in Round Up and it is considered non-selective, meaning that no matter what it comes into contact with, intentionally or not, it is going to do damage. We typically see the effects of this chemical within a week of application. If your foster hollies seemed to be perfectly healthy before this area was sprayed and then suddenly declined in health, I would suspect this is the cause. It is impossible to say for certain without seeing them, but you can always take a sample to a reputable garden center/nursery in your area or to your County Cooperative Extension Service for a positive diagnosis. Usually when non-target plants are exposed to glyphosate, their foliage first turns yellow and then we see defoliation and dieback. If this is the case, unfortunately the damage is done and irreversible. It will be a waiting game to see how much damage was done, but you should have someone look at a sample just to make sure there is not something else causing the decline in health of your evergreens.
