Broadleaf herbicides?

[Ralph Wiggum]

The previous owner of our house killed the lawn before we moved in, so late last summer, I ripped out the backyard and reseeded. For the most part, it came in very well and looks great. Now, I am noticing quite a few broadleaf weeds in it (I have neighbors on both sides that could care less about their lawns).

I'd like to get a handle on these weeds, but I am a little leary about using any herbicides on such a new lawn (I planted the last week of August). Are my concerns unfounded, or should I let the lawn get more established before I tackle the weeds?

Also, what's a good choice for a weed killer. I've got a few dandilions (and judging by the neighbors yards, I will be getting a lot more ) and a bunch of others that I'm clueless about. I will try to get up a picture of the main culprit if need be. This is our first lawn, so I am relatively clueless.

[Tom7227]

tackle now, punt later. Weed killer with Trimec will biff most of the broadleaf weeds. I get a concentrate and mix it in a little hand sprayer like you clean windows with. You can just go out and touch up the areas that need it. Try doing it in the morning when grass is still wet with dew.

Also - Get some info on 3 applications of fertilizer this year and the place will look great. Best bet is a fall winterizing fertilizer applied at the right time of the year.

[hotrod1]

If you have mowed it a couple times, you should be good to go with herbicide.

Have you applied any fertilizer to the lawn this year? I like to have the lawn fertilized before i applied herbicide to my lawn so it makes the turf stronger and not get affected by herbicide. Basically, you shouldn't apply herbicide to your lawn durring stress times...Low fertility, drought conditions, etc.

The product I personaly use with great success on broadleafs is from Lesco and it's called Momentum...It is kinda high priced but works great. They also have other broadleaf herbides that will work good too and maybe less expensive.

When you pick out a product, read the label and apply the herbicide accordingly.

[H2O Milfoil]

The suggestions I've read are pretty much right on. Most broadleaf weed control products will be effective on the weeds and safe to the juvenile grass. Note that I said "juvenile" and not "seedling" grass. Broadleaf weeds are easily controlled by Trimec or other products. If you spray this time of year, be mindful of your wind drift onto nearby ornamental broadleaf plants; don't spray in a wind. Don't spray near a food garden. Perhaps shouldn't spray under the canopy of a tree. You may want to consider not spraying at all if your lawn is used by your kids, pets, rabbits, etc. Or keep them off for 2 or 3 days, or a rain, or a mowing. Most broadleaf herbicides will volatolize in warm temperatures; that is, they will evaporate, become vapor, and drift around...up into tree canopies, blow sideways into ornamentals or gardens. This is true whether you use a spray product or a granular product. Be mindful of all the conditions. If you can smell it, then it is capable of moving around to non-target areas.

As another poster mentioned, if you have mowed the new grass a couple of times, it is most likely old enough to withstand the application of spray or granular broadleaf control products.

But the above is only about broadleaf weeds, which are the most easily controlled. If you have a creeping charlie problem, that takes a bit more work.

You should also pay attention to the annual grassy weeds. Crabgrass, foxtail, barnyardgrass, etc. These are warm weather grasses that germinate right about now (mid to late May). You need to control these with pre-emergence products (i.e.- kill 'em before they come up, not after). If you or your neighbor's lawns have a crabgrass problem, you probably have a ton or more of seed in your turf, too. Your seedling grass sounds old enough, so you may need to apply an annual grass control product. Put it down and water it in. The rule of thumb is to apply about the time lilacs bloom, although I prefer to say about the time the apples and rhododendrons bloom. Like, right now!

Definitely post some pictures!

Feel free to ask me any questions. I am a (former) turfgrass breeder and turfgrass agronomist. I've got a lot of green mileage under my belt!

Effective weed control begins with accurate weed identification!

[Eric Wettschreck]

I'll let the lawn experts advise you on what herbacide to use.

I had the same problem with neighbors not caring about dandelions. Now, in the fall when I spray my lawn with 2-4-d, I spray theirs too.

[catfishkid]

one tip i learned from a sod farmer is to mix some dish soap in

with your 24d . the formula i use and i stress that I USE is

2oz of 24d per gal. and 1 cup of soap (dawn) in each 15 gal of water of my sprayer. the soap helps the chemical kill the clover. they sell special stuff for this but soap is a lot cheaper

just my 2cents

[paul pachowicz]

boy oh boy could we ever discuss this to lenghts. There are products on the market specifically formulated and labeled for clovers and woody plants that contain an "ester" that will penetrate the leaf which allows the systemic chemical translocate to the roots. I use "Brushmaster" & "Redeem R & P". Adding Dawn, to me is an extra step. I'd have to read back but, I don't know of research that would confirm using products "off label" that would improve the performance, testamentals perhaps. Cheaper is not always the most prudent way to treat a target nuisance.

[Tom7227]

The dish soap acts as a 'surfacant' (sp?) that allows the water and the herbicide to spread more easily across the leaf of the plant. That's all it does, besides making your lawn smell nice for a short time.

[LwnmwnMan2]

The dish soap acts as a 'surfacant' (sp?) that allows the water and the herbicide to spread more easily across the leaf of the plant. That's all it does, besides making your lawn smell nice for a short time.

Tom's right. It does nothing other than letting the chemical spread across the plant leaf.

We've all seen how the drop of Dawn on a greasy plate on TV commercial, how it spreads across, that's basically what it's doing on the plant leaf as well. I use a commercial grade product, but I know of alot of guys that use soap as well. Biggest problem you're going to have if you use too much is it will want to foam up if you have a tank sprayer behind a 4 wheeler or your mower.

Tom - only suggestion with your earlier post is, with using the Trimec, the liquid version, if you're applying it when there's a dew, you're in effect diluting it down, since you've already got it mixed with water. Usually the only time you need to apply herbicides with a dew is when you're applying granular products.

I too use Momentum. I use it at a rate of 1 oz of product per 1000 zq ft, so to do an acre, it would take 43-44 oz of chemical, in however much water you're going to use to cover said 1000 sq ft.

[BobT]

I don't know about that lwnmwnman2. In my farming operation I have found that the absolute best time to apply herbicide is in the morning while the plants are wet with due.

The only explanation I can come up with is that the herbicide is now poised to be readily absorbed by the plant as it "wakes up" for the day. Also, being the coolest part of the day, the plant is not under stress from the day's heat.

Also, I don't believe most homeowners have to be concerned about dilluting their herbicides too much. Simply put, most homeowners over-apply anyway. For example I mix my field sprayer with 2,4D at a rate of 3/4 pint per 10 gallons (per acre rate). This is the highest concentration recommended by the product manufacturer, Dupont. I don't have the booklet in front of me but I believe the preferred concentration is actually closer to 3/4 pint to 20 gallons.

I believe the moisture helps the plants absorb the product.

Bob

[LwnmwnMan2]

I'll agree to the over-applying part.

As far as the concentration mix goes, it's going to vary from one product to the next, depending on the amount of active ingredient in that product.

The Momentim that I use, it's rated for 1.1 - 1.5 oz per 1000 sq ft. I personally want to save money, plus I do not want to use chemicals any more than I have to, and have found that I get decent results at 1 oz per 1000 sq ft, so I run it at 1 oz.

When you have multiple properties to maintain, you're applying all day and I've not had any issues with appying when there wasn't a dew out. That's why 99% of commercial applicators won't do a "weed-n-feed", so you don't have to worry about the dew.

Using a surfactant will help with absorbtion as much as having a dew on the ground.

[sparcebag]

I think the dew gives it better coverage the same way dish soap does,dew has already dispurced the moisture.Does'nt soap contain gycerol,which used by itself reduces surface tension of water causing it to flow instead of bead.

[Dotch]

Just to throw my $.02 worth in as an agronomist and member of several weed science organizations, soaps are essentially surfactants, make water "wetter", break the surface tension, spread more evenly, and so on. Richard Zollinger at NDSU is one of the foremost experts on surfactants and their use in the US. Google NDSU's HSOforum and plug "Adjuvants" into their search HSOforum slot and you'll probably find out more about surfactants, oils and other adjuvants than you care to know.

Bob's partially right in that especially when dealing with growth regulators like the phenoxy's (2,4-D, MCPA, MCPP,) or dicamba and to some extent chlopyralid where we're used to using 10 gpa or less, dew can have a posititve impact on their performance. Part of this is likely due to the fact that during the early morning hours, the stomata on the weeds we're trying to control are still open. When we're dealing with products using higher gallonages and products whose activity tends to be more contact control in nature, that advantage generally is absent and can actually hurt control because of the dilution effect someone mentioned. This gets even more involved when we're talking about products like glyphosate, (usually lower water volume) and some of the interesting little quirks surrounding weed species and time of day. I would advise to be careful about adding surfactant willy-nilly as it's supposed to "help". Most products will tell you on the label if additional surfactant is required or under what circumstances it may be advantageous to use it. Adding surfactant to 2,4-D for instance may be fine on turf but would never advise that people use it on corn or sweet corn. The crop tolerance can be marginal to begin with and use with a surfactant has the makings for a real disaster.

[LwnmwnMan2]

Also, the reason I keep saying how many oz per 1000 sq ft, is that I use 48 oz of chemical in 12 gallons of water. However, I use 12 gallons of water to cover just over an acre of turf.

Other people using skid sprayers, where you see the 200 gallon tank in the back of a pickup, they'd use 1 gallon of water to cover 1000 sq ft.

[Ralph Wiggum]

Here's the two main culprits:

Culprit #1

Culprit #2

[hotrod1]

I believe #1 is Hoary Alyssum and #2 is Spiny Sowthistle.

[Dotch]

You're close hotrod1 but would respectfully disagree. The top photo appears to be horseweed or as some call it, marestail. The bottom one is a little trickier, but that appears to be one biotype of prickly lettuce. There is a lot of variation in appearance in that particular species. This one has more dentate type leaves (rough saw-toothed edges) as opposed to the more deeply lobed type. The key identifying characteristic would be the spines lining the underside of the midvein on the leaves.

[Ralph Wiggum]

I think you're correct, Dotch. Thanks! Will 2,4-D take care of these?

[sparcebag]

I Use it now and its been working! I had black dirt from a pasture. I've seeded grass last fall in snow, grass is doing real good but its half weeds and i spot treat now with great results.

Wiggum what is your field in chemistry?

[Ralph Wiggum]

Wiggum what is your field in chemistry?

I'm an analytical chemist. I work on the R&D side in the pharmaceutical industry.

[Dotch]

I think you're correct, Dotch. Thanks! Will 2,4-D take care of these?

Yes on both, especially in a lawn situation. Have both species, primarily as waste area or fenceline weeds. Sometimes these appear as winter annuals so treatment in the fall can be benfecial. If you're spraying for dandelions then you'll knock those out too. In spring postemerge applications, controlling before they bolt (elongate) improves control and avoids use of increased herbicide rates.