[mmicha]

Hello,

I've been trying to combat a variety of weeds in my yard before they get going.

I've sprayed them with 3 different products with different chemical makeup, but most are not dying. Even after 48 hrs... They don't even look phased...

I've tried Weed B Gon, Weed B Gon CCO, and a Roundup for Lawns product.

Is there any explanation why this would be happening? Its April and getting warmer.

Thanks

 

[g-man]

Round up for lawns and weed b gon are similar products.

A couple of possible reasons, most products need the weeds to be growing. This means warmer temps and maybe some fertilizer. In what state is Glen Ellyn?

Second, some weeds will needs 2 weeks to show signs of wilting and repeated applications. 48hrs might not be enough.

Lastly, some weeds are grasses and the products listed will not control them. Some weed grasses only respond to the real round up.

 

[mmicha]

Round up for lawns abd weed b gon are similar products.

A couple of possible reasons, most products need the weeds to be growing. This means warmer temps and maybe some fertilizer. In what state is Glen Ellyn?

Second, some weeds will needs 2 weeks to show signs of wilting and repeated applications. 48hrs might not be enough.

Lastly, some weeds are grasses and the products listed will not control them. Some weed grasses only respond to the real round up.

Glen Ellyn is a Chicago suburb. One weed I believe is ground ivy. I know it is difficult, but I expected some appearance change.

 

[probasestealer]

@g-man is right, the weeds need to be actively growing. Typically I wouldn't fertilize until you've mowed the turf 2x. It's possible the chemicals will still work.

I'd recommend the addition of a surfactant, especially to target the ground ivy. Likely the more difficult weeds will need 2-3 apps of CCO.

 

[mmicha]

@g-man is right, the weeds need to be actively growing. Typically I wouldn't fertilize until you've mowed the turf 2x. It's possible the chemicals will still work.

I'd recommend the addition of a surfactant, especially to target the ground ivy. Likely the more difficult weeds will need 2-3 apps of CCO.

This is where I get a bit confused on lawn care. Are we suppose to fertilize ahead of cutting the lawn? I applied a fertilizer w/ pre-emergent about a week ago for crab grass. I've not actually cut the grass yet. I based that on the ground temperature...

Even though the weeds are green, living right now... they need to be "growing" for the killers to be effective? My goal was try and knock them out before they become too much.

Thanks

 

[probasestealer]

@mmicha it's all very confusing and the big box stores and big name brands (Scott's, Pennington, etc) make it more difficult.

Ideally you would drop a pre-emergent (I like Dimension) to prevent the germination of annual spring/summer weeds, such as crabgrass. Typically crabgrass emerges early spring, but you really don't see it until summer. The big brands add fertilizer for convenience and they can also charge a pretty significant premium for that product. If you're an average homeowner who does very little this is a good step.

However, you are on this site which means you aren't the average homeowner. Many of the weeds you see now are either perennials (come back every year from roots, rhizomes, etc) or they are annuals that germinated last fall. Just because they are currently alive (green) doesn't mean they are growing at their full potential. You'll notice that many of these weeds will take off about the same time the grass does, usually growing a different rate, typically faster. That is the ideal time to hit them with the correct herbicide.

Want to make it more complicated? The more surface area a weed has (the larger and/or taller it is) the more area it has to take up the herbicide and that typically makes the herbicide more effective. So you want to spray the weeds several days after your last mow, don't spray after mowing if you can help it. I typically wait a day or two to mow again. Surfactants are essential with some weeds (you can buy cheap non-ionic surfactant on Amazon) by allowing the product to "stick" better.

So you fertilized, no big deal. It does force top growth of the grass sooner, but it may also encourage the weeds.

Typically we recommend waiting to fertilize so the desirable turf can wake up and focus on root growth. Hence mowing 2x.

I ran out of time this late winter and had to buy dithopyr (dimension) with fertilizer also. It cost $35 for the bag. I was at Lowe's and later found Dithopyr without fert at a high percentage that will only cost about $10 to spread next spring. I mention this because you want to read for product ingredients. Plus even when we know better, we can't always source the product, or are willing to pay the shipping costs to get a granular product.

Sorry for the rambling post. I cringe when I hear ppl at Lowes and HD giving yard advise..

 

[Jconnelly6b]

@mmicha 48 hours isn't a lot of time for weed killer to take effect, especially with persisting cool weather. I would suggest waiting another week before you apply any other herbicides, as you may cause some damage to the desirable grasses if you have sprayed multiple applications in the same spots.

Wait until the temperature warms up a bit, and you should begin to see results. I normally don't see wilting until a week or so after application. Also, selective herbicides don't kill like roundup does - the plant is just going to shrink and disappear - not like with roundup where you get a very pronounced browning and then death.

Most labels will say to not make repeat applications closer than 2 weeks apart. I got anxious last fall (also when temps were cooler) and did 2 applications only a week apart, and nearly killed all the turf in the process because of too much chemical on the good grass.

I am learning as well, this lawn care stuff really requires some patience.