Roundup Can Be Used Safely Around Trees.

We will feature some questions we get from customers periodically. I think the answers will better help you manage your outdoor living spaces.

Q. I have several fruit trees (apricot and plum) which have meadow grass in their wells and around them.  The grass is a wide bladed variety that had an extensive root system including rhizomes.  Can I safely spray roundup on the grass without harming the trees?  This assuming that I cover the trunk and canopy from overspray.  Does the Roundup end up in the ground only to harm the trees roots? Greg.

Glyphosate is the active ingredient in Roundup.

 A. No problem spraying the grass, Greg. Yes, it is best if you put some cardboard or something to keep the overspray off of the trunk. If the trunk is woody and not green it should pose no problem but it is better to be safe than sorry.

            I would cut the grass back, spray it with water to get the dirt off of it, make sure it is watered and happy, then kill it with Roundup. Apply just enough to wet the grass and no more.

            You do not need to, or should you, overwet the grass. Apply enough to wet the leaves. You can go back a few hours later and respray it if you are not comfortable with just wetting the leaves.

            Roundup has been reported to work a bit better if you put in about ½ tsp of dishwater detergent in the spray mix just before you spray.  Adding a small amount of soluble nitrogen fertilizer to the mix (such as ammonium sulfate) is also reported to help it work better.

            The detergent or wetting agent helps the Roundup penetrate the grass blades. 12 hours later 95% of the Roundup will be all absorbed and it no longer makes any difference if the grass gets wet from a sprinkler or not.

            You should start to see dieback in about 7 to 10 days unless they have adding something to the Roundup for a quicker kill. Viragrow carries both Glyphosate Pro and Ranger, another formulation of Roundup with the same active ingredient.