Glyphosphate toxicity to Cactus

Asked November 20, 2015, 11:00 AM EST

Our HOA has declared war on bufflegrass: a good thing. But rather than remove it, they are having intense (conc. higher than Roundup) commercial spraying of glyphosphate. I cannot find info (from scientific real sources such as .edu) about its immediate or long term toxicity to the spray on cactus or our desert trees. Do you know of any research showing what it may do?

Pima County Arizona natural resources herbicides

2 Responses

Hi, I'm asking our weed specialist about your situation but due to the thanksgiving holiday it might be a week before I have an answer. Peter

Hi again,

I have more information from our weed specialist. Direct spraying of cacti by Roundup repeatedly will probably kill most cactus species but they can withstand incidental spray contact (whole plant is not sprayed) intermittently and can survive a single direct spraying. Generally, we would recommend spraying grass specific herbicides for grass control (e.g., fluaziflop, sethoxydim or clethodim on bermudagrass) to avoid injuring the cacti. Unfortunately, this class of herbicides doesn’t work well on buffelgrass but maybe repeated spraying would eventually do it. Manual remove of buffelgrass would be effective in this case but understandably hard around cacti.

Peter