Spraying weed control @ night due to high temps in day time?

Question

All the weed control sprays warn not to spray their product on the lawns if the day time temperature is above 85 degrees.

Can we spray it in the evening after the temperature drops under 85 degrees? Or are we going to have to wait until the fall to get rid of the many weeds in our lawns

Answer 1

it depends on what weeds and what type of grass you have. many chemicals in the south actually work better when the temps are hot. however you do bring up a good point. if you have a grass that is a cool season grass ( fescues, bluegrasses, ryegrasses......) it is already stressed enough from hot temps. but im guessing that you dont considering you are above 85 degrees. late night spraying can be effective. many colleges and athletic fields do this when on water restriction. they also fertilize in the late afternoon as well.

pros- cooler temps, less phytotoxicity ( sun breakdown) less stress

cons- less sun, dew in morning

good luck!

Answer 2

Well, I tend not to read such directions, so I recently sprayed broadleaf weed killer on a lawn on a pretty hot day -- likely it got over 85 degrees.  The weeds died, the lawn did not.  So I think your idea is a good one, certainly better than my "plan" of spraying during the middle of a hot day.