Broadleaf weed pre-emergent?

[Peabody]

I'm accustomed to applying a grassy weed (i.e - crabgrass) pre-emergent treatment in the early Spring, but would also like to do something to prevent broadleaf weeds from coming up in the Spring. I'm told now is the right time to treat for my area, which is Northeast Oklahoma.

In the store I find the usual Barricade pre-emergent, which is mainly for grassy weeds, but supposedly has some effect on broadleaf weeds as well.

But I also find Greenlight Portrait (Isoxaben), which is specifically for broadleaf weeds. But, it's twice as expensive as Barricade, and conspicuously missing from the list of fully controlled weeds is clover, which is kinda my main thing.

Does anyone here have experience with either of these for broadleaf weeds? Or, does anyone know what the lawn services apply in the Fall to control Springtime broadleaf germination?

[Peter H]

I'm from north of the boarder, but was in the business for over 10 years and have taken courses on the subject of weed control.

I'm not familiar with either of the products that you mention but can say this.

If you've got a weed problem a broadleaf week killer in the fall and again in the sprintime, when the weeds come up is what I would recommend. The broadleaf weed killer work on weeds by supplying a growth stimulant which forces them to grow at a rate that causes them to die. Grassy weeds are handled very differently.

For many years you had to spray a pre-emergent for grassy weeds, primarily crabgrass, but there have been new products come on the market ( 10 years or more now) that work as post emergents as well. They are expensive though. I would suggest that you wait until next spring to apply the grassy weed killer ( pre-emergent) and see how your control is. A pre-emergent laid down in the fall is normally not very effective against grassy weeds the following spring.

As I say, I don't know your area though and don't know your weather conditions.

You might try..alt.home.lawn.garden

Peter H

[Phisherman]

Overseed in the fall. Eventually the grass will be so thick you'll have very few weeds. Buy seed that is 99% weed free. Cool-season grasses grow roots during the winter months.

[Norminn]

It's been 4 or 5 years since I have done serious battle with broadleaf weeds, but I don't recall any pre-emergents for broadleaf. What worked very well for us was Weed B'Gone, which I believe was Ortho. There once was a separate formula of it for St. Augustine grass that we have in Florida. It really will kill just about everything with broad leaves, so have to be cautious around desireable plants. Dollar weed was the main foe, and we surprised a couple of lawn care companies when they saw how it worked, but it worked on other stuff. It should not be used during times of drought or stress, and best when weeds are actively growing. It is taken up through leaves, and shows results within a day. We usually fertilized a week or two prior to be sure everything was growing nicely.

[SteveB]

Look for the ones that have amine at the end of the chemical breakdown.

Steve

[Joseph Meehan]

Every area has it's own problems and solutions. Around here no one would try to kill broad leaf weeds with a pre-emergence material. It is much too easy to do that later. Personally I don't like to use general applications, so I spot treat them. Less pollution, less poison, saves money and it works.

[Joseph Meehan]

I seldom do any overseeding, but you are right about the best weed control is a healthy grass, at least in the cool grass areas.

[KC]

Only if you're using usenet. They've got a really bad attitude about anything coming from google groups.

KC

[Peabody]

Thanks for the replies.

My lawn is bermuda, so there wouldn't be any point to seeding that now.

I know that the lawn services do something to prevent germination of broadleaf weeds. I know this because my neighbors who use these services don't get those weeds in the Spring like I do. Also, when I checked in the past, I found that all of these services apply pre-emergent in both the Fall and the Spring. But I don't know what chemical the services use for that.

Of course I can spray the weeds when they come up, but it would be nice to nip them in the bud, so to speak.

I've posted in the other newsgroup, so we'll see what they have to say.

Thanks again.

[Norminn]

Lawn services sell a hell of a lot more chemical than is needed. We talked to several that sell only monthly applications of "something", for bugs, fert., weeds, whether it is needed or not. They would not break out only the services we wanted. We rehabbed our condo lawn from half dead, with large areas of bare soil and loads of weeds back to entirely healthy, lush and weed-free. One application of broadleaf herbicide got rid of 98% of those weeds....pre-emerg. used for grassy weeds, goose grass, was effective but it is tough to get rid of entirely and I know crab grass can have runners 20' long. We chose to go with less than "high maintenance", for Florida, which means fert. 3x per year rather than 4, used slow release nitrogen so's it doesn't wash away in the first rain, and mowed optimum to keep lawn from drying out as fast. Once the lawn was thick and healthy again, regular herbicide app. was not needed....just hand pulling a weed here and there helps keep another few hundred seeds from being deposited. If you get rid of most of the broad leaf weeds in one app., you will still have seeds present that don't germinate for 2-3 years, in addition to what lands from birds, but healthly, thick grass helps keep them from germinating. Good watering and mowing practices do a great deal to keep weeds down .. didn't quite buy that until it was accomplished. The best recommendations aren't from the Scott's label or some contractor selling chem. - check with your local extension service for weed identification and treatment, soil analysis, special pest problems.

[Norminn]

Once more, for emphasis: pre-emergents for crab grass are tough on birds, fish and other critters, especially near waterways. Timing is critical. If possible, hand removal is better, but if chem. are used they should be applied only when, where and how they will have best effect.

[dpb]

It's highly likely that whatever the commercial weed service are using are licensed so you can't get them, anyway.

Many of the "preemergent" herbicides actually work not by preventing germination but by the newly emergent seedlings being unusually susceptible--that's the primary action for most of the crabgrass preemergents.

As usual, my general recommendation is to talk to your local County Agent and peruse the local ag-school web for tips appropriate to you area (in this case, Ok State). Being you're in the NE corner of the state, Mizzou, KSU, and UofA are all in areas which will have similar problems. I'm in KS but the SW corner so we're night and day different from there.

As a side note, w/ Bermuda and as much moisture as you guys normally get, I would suspect there must be some soil ingredient lacking to not have such a dense cover that annual broadleaf weeds would be much of a problem at all. Talk to the County Agent about how to do soil sampling as well...

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[dpb]

Don't know anything about Greenlight Portrait, but Banvel (and I forget what is active in it) is one very effective one. You may not be able to get it w/o applicator license or ag producer ID, however, I'm not sure of OK rules. You have to be careful with it to not use it where it can get carried underground to root system of trees, bushes, etc., or you may have collateral damage. But it'll surely help on any broadleaf germination problem! :)

A side note is that clover is indicative of nitrogen-poor soil. If it is doing well, it shows your soil is short of N and after a few years will tend to retreat on its own and the grass fill in as soil nutrient quality is built up. Overall, I'd recommend letting the clover go and not considering it a weed but a really cheap "feed" portion of the "weed-n-feed"...

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[Norminn]