The Grass Doctor

Colorado Bluegrass/Fescue can I use Ortho weed be gone and fertilizer together without damaging/burning grass?

I would like to know if I can use Ortho's Weed B Gone CRABGRASS and a fertilizer at the same time, Liquid Crabrass killer (of course) and then granual fertilizer if I wait 24 hours before I water the fertilizer?

Public Comments

1. despite what Ortho says, I'd wait 72 hours before applying fertilizer, and then mix the fert at about 1/4 strength and apply over several days - sure, you can blow it on there as specified but it doesnt hurt to go a little slower, sort of like the idea of fertilizing your houseplants with every watering - if you mix the fert in at 10% of the 'apply every 2 weeks/1 month' B.S. commonly seen on the labels. Less fert, grass does fine on very little. I wouldn't worry about crabgrass myself, the worst weed in a lawn is thistle, and that can be eradicated not by spraying, but by walking to every individual plant and painting it (yes, use a brush) with Roundup mixed 50-50. Nasty, but effective. Don't spray this. If you use Ortho, don't let your kids or pets play on that lawn for a week, check out the number of dogs that had liver complications and mental problems after ingesting grass treated with some of the broadleaf weed and grass agents. Not good.
2. I wouldn't worry about the crabgrass as long as it is green. Now dandelions are something else. I use any brabd of a Weed And Feed fertilizer on my Kentucky Blue grass and red fescue lawn. Kills dnadlions . Don't know about crabgrass but healthy lawn may choke it out.