Weed Control Around Saguaro

Q. I have a 25-foot Saguaro cactus with at least 7 arms in my Palm Springs landscape. My gardener just put Roundup around it to control weeds. We had this done a few years ago, and since then the Saguaro leans dramatically.  I didn't want him to put it there.

Saguaro cactus in a Sonoran landscape in Parker, Az.

A. I wouldn’t spray Roundup close to it unless you protect the Saguaro. It says on the label to protect anything green because it is a general killer. It was developed originally is a grass killer but it will kill nearly everything if you apply the right concentration.

The base of Saguaro will develop tough brown "bark" areas as it gets older. Even though it might be there, protect the base with cardboard when spraying systemic weed killers like Roundup.

            An older Saguaro like yours should be developing some woody brown areas towards the base as parts of it remain green but that’s not enough. Anything you don’t want damaged or killed, protect it. An easy way to do that is a cardboard barrier to protect the Saguaro. After you’re finished spraying you can either remove it or just use it as a shield when you’re spraying Roundup close to it.