Crabgrass and how to kill it - Page 2 - PeachParts Mercedes-Benz Forum

TylerH860 · #16 08-23-2010, 02:04 PM

Its been such a hot summer I've been fighting the stuff as well. The stuff seems more heat resistant; the whole damn neighborhood is infested with the crap.

I figured there was nothing I could do for another few months.

SwampYankee · #17 08-23-2010, 02:09 PM

Quote:

Originally Posted by TylerH860

Its been such a hot summer I've been fighting the stuff as well. The stuff seems more heat resistant; the whole damn neighborhood is infested with the crap.

I figured there was nothing I could do for another few months.

If someone could come up with a turf-type perennial crabgrass they'd make a fortune! It is amazing how heat and drought tolerant the stuff is.

suginami · #18 08-23-2010, 02:12 PM

I don't think it is a good idea to kill your whole lawn and start over.

The problem is that eventually weeds like crabgrass are going to come back.

Controlling lawn weeds are a year-round, continuous program of keeping a healthy lawn, using a pre-emergent chemical to prevent this stuff from germinating, killing them as they grow, and then re-seeding in the spring and / or early fall to limit the amount of space where weeds can grow.

At the end of the day the only way to prevent crabgrass is asphalt or cement.

dannym · #19 08-23-2010, 02:48 PM

I'm dealing with this issue too. Lots of good ideas.
What kind of grass is best to seed with? I have St Augustine grass but I don't ever see any seed for it in the stores.
Maybe Bahia or some of the new grasses that are out now?

Danny

kknudson · #20 08-23-2010, 03:25 PM

Go back in time.

Kill the person that decided Bluegrass was the Standard.

Establish Crabgrass as the Standard for a beautiful Lawn !!!!!!!!!!!

SwampYankee · #21 08-23-2010, 03:34 PM

Quote:

Originally Posted by suginami

I don't think it is a good idea to kill your whole lawn and start over.

The problem is that eventually weeds like crabgrass are going to come back.

Controlling lawn weeds are a year-round, continuous program of keeping a healthy lawn, using a pre-emergent chemical to prevent this stuff from germinating, killing them as they grow, and then re-seeding in the spring and / or early fall to limit the amount of space where weeds can grow.

At the end of the day the only way to prevent crabgrass is asphalt or cement.

If it's less than 50% weeds and crabgrass it can be brought back relatively easily without starting over. More than that really depends on how much time and effort the owner wants to put into it (or how much they want to pay someone else to do it) or how patient they are. The issue with starting over completely with rototilling is that you bring all of those weeds seeds up to the surface.

There is a seed bank of weed and crabgrass seed present in the soil (there are university studies showing that crabgrass seed can stay viable in the soil for 50+ years), just waiting for the right combination of sunlight and water to germinate. One way to combat that without chemicals is do build up your own seed bank of desirable grasses by continuously over-seeding. A lot of municipalities and sports field maintenance companies in New England have gone this route on their sports fields, over-seeding every two weeks while in play and having the cleats work the seed into the soil, since pesticides have been completely removed from their arsenal on any field that K-8 kids can play. And it's probably only a matter of time before they're banned on high school fields.

That's true for asphalt and cement as long as there aren't any cracks!

SwampYankee · #22 08-23-2010, 03:44 PM

Quote:

Originally Posted by dannym

I'm dealing with this issue too. Lots of good ideas.
What kind of grass is best to seed with? I have St Augustine grass but I don't ever see any seed for it in the stores.
Maybe Bahia or some of the new grasses that are out now?

Danny

I like to kid my FL friends that all they have is cultivated crabgrass.

It depends on what your expectations of a lawn are and your cultural practices (water, fertilization, pesticides, etc.). Organic, conventional (synthetic fertilizers and pesticides) or combination thereof?

I'm not real familiar with the warm season turfgrasses but some of the newer Bermudagrass varieties are damn nice with better cold tolerance (in parts of FL through the transitional zone they over-seed with turf-type ryegrass in the winter since the Bermuda goes dormant) than the old ones.

toddyvol · #23 08-23-2010, 04:49 PM

I have both Zoysia and Bermuda. The Bermuda is the best IMHO. It chokes out most anything including crabgrass. In the winter it turns brown but that's okay with me. The Bermuda loves the heat and I bet it will grow on a rock.

The Bermuda does creep which can be a problem with flower beds and such.

G-Benz · #24 08-23-2010, 05:35 PM

Hot weather grasses (like Bermuda and St. Augustine) are drought tolerant and have the benefit of crowding out weeds. The clay content of Texas soil has the added benefit of preventing much root growth, so stubborn weeds that flourish up north are benign down here.

Mowing short in this heat is a death sentence to grasses that aren't drought tolerant, and can introduce disease with the short blade and exposed root system. I am assuming that the only grasses that can grow in CT are Kentucky Blue or Zoysia, and perhaps Fescue.

This is about the time of the month to see secondary weed growth that seemed to have been handled during the spring pre-emergence applications. All you can really do is more chemical application to prevent further spread. But if your neighbor has a bumper crop of crabgrass, you will have a tough time keeping yours in check...

beevly · #25 08-23-2010, 06:15 PM

Good info Swamp.

I had been gradually losing the fight for years, and I even tried purposely giving up the fight and letting it all go to crabgrass. That part was fine, that's exactly what happened. I mowed it and it actually looked fine, thick and green. The problem was that crabgrass kills the other desireable grasses (I'm told it actually secretes something to help with that) but the following year it, and nothing else, doesn't emerge until later in the season. The result was next spring all I had was dirt and dried up dead crabgrass from the year before until late June - July when the crabgrass all came up.

2 yrs ago the yard was dug up for a pool replacement, new septic line etc. and we had the opportunity to start over. The first year was fine, I could keep up with hand pulling the occassional crabgrass. This year it started coming back with a vengence. I used Weed-B-Gone max for crabgrass as soon as I realized what was happening, somewhere around late June (SE Conn). I bought a good sprayer so I could easily target individual clumps and leave the good stuff - I could really get it down into the base of the clump with very little overspray, and now all I do is go around and pull up the stray crabgrass clumps I find, about 10 min max.

I'll also take the advice to lime and overseed and take it from there. I think the key was that I did the weed-b-gone early when i first saw the battle beginning.

Oh, and lots of watering, fortunately I have a good well.

SwampYankee · #26 08-23-2010, 08:11 PM

Quote:

Originally Posted by G-Benz

I am assuming that the only grasses that can grow in CT are Kentucky Blue or Zoysia, and perhaps Fescue.

CT is firmly in cool-season grass zone. Bluegrass, ryes, fine leaf and tall fescues are the main choices. Some folks have zoysia which does well in the spring and summer but goes dormant for the other half-ish year.

We have been doing some testing with a few New England universities with some new cool-tolerant Bermudagrass varieties in sportsfield application with some promising results.

SwampYankee · #27 08-24-2010, 08:19 AM

Quote:

Originally Posted by beevly

I had been gradually losing the fight for years, and I even tried purposely giving up the fight and letting it all go to crabgrass. That part was fine, that's exactly what happened. I mowed it and it actually looked fine, thick and green. The problem was that crabgrass kills the other desireable grasses (I'm told it actually secretes something to help with that) but the following year it, and nothing else, doesn't emerge until later in the season. The result was next spring all I had was dirt and dried up dead crabgrass from the year before until late June - July when the crabgrass all came up.

2 yrs ago the yard was dug up for a pool replacement, new septic line etc. and we had the opportunity to start over. The first year was fine, I could keep up with hand pulling the occassional crabgrass. This year it started coming back with a vengence. I used Weed-B-Gone max for crabgrass as soon as I realized what was happening, somewhere around late June (SE Conn). I bought a good sprayer so I could easily target individual clumps and leave the good stuff - I could really get it down into the base of the clump with very little overspray, and now all I do is go around and pull up the stray crabgrass clumps I find, about 10 min max.

The issue with the crabgrass is that it is so aggressive that it crowds out the turfgrass varieties in its search for sunlight, nutrients and water, eventually killing the turfgrass. And unlike crabgrass, the turfgrasses never grow enough to get to seedhead stage since most folks prefer their lawns to be less than 1 ft.+ tall.

Since the turfgrass isn't ever reseeding, what you're left with is the vast expanses of dirt, filled with decades of crabgrass seed waiting for their chance to germinate. It really is incredible how opportunistic, even predatory almost, crabgrass is.

It is a lot easier to control the crabgrass pre-emergently than after the fact (although as you have found, there are some good post-emergent products) whether it be conventionally (Dimension is a great pre-emergent control usually found in combination with fertilizer as a "Step 1" product-curse the advent of 4-Step programs!), organically (corn gluten meal at 20 lbs./1000 sq.ft.), routinely overseeding during the course of the season (never giving the crabgrass a chance to get going) and fertilizing in the late fall (the turfgrass continues taking the nutrients in right up until the ground freezes and stores them over the winter). Or some combination of the above. Although remember, conventional pre-emergent crabgrass controls will also kill turfgrass seeds for the same period of time (corn gluten meal to a lesser extent). Grass is grass as far as it is concerned.

Crabgrass will begin germinating when the soil temp reaches 60, for a period of at least a week. Mother Nature is often in disagreement with Scotts (4-Step pushers

) as to when the best time to put that crabgrass control down as she doesn't work by a calendar and care about spacing subsequent applications out enough to sell customers 4 different bags of product. Scotts would have you put Step 1 down in March since they want to sell you Step 2 for late May/Early June. The best time to apply that "Step 1" is usually early June, but that screws up their sales model. In the spring, the turfgrass is usually thick, healthy and growing right along pretty well when the soil temps reach 60*so the crabgrass lies in wait. Summer's heat, humidity and (often) dryness brings stress to the turf, thinning it out and slowing its growth. And that's when the crabgrass really "shines" taking the opportunity presented. Pre-emergent controls generally last 8-16 weeks, depending on the product. With a March application, that 8 week product is L-O-N-G since broken down by the end of June and the 16 week product leaves you vulnerable for the better part of July and early August.

Quote:

Originally Posted by beevly

Oh, and lots of watering, fortunately I have a good well.

As far as watering, you are better off watering infrequently for longer durations rather than, say, 20-30 min./a day, every day. With frequent irrigation the roots stay right up at the surface, weakening the turf and making it more susceptible to the heat and drought. Bluegrass, which is the least drought tolerant of our cool season grasses, needs 1.5" a week to thrive. What doesn't come from the sky would need to be supplemented via irrigation. Get a rain gauge, or even a cup, and put it in the middle of your yard and see how long it takes to get 0.75" in it. Then you can run your irrigation for that amount of time, twice a week, soaking the soil deeper and training those roots to follow it down. Deeper roots=Stronger plants. Fescues and ryes only need an 1" or less so you can adjust those amounts down accordingly depending on the varieties you've got. Assuming we get at least 0.25" of rainfall (less than that will just moisten the surface), make up that difference later on in the week. Obviously you don't want to change your irrigation practices in the summer, but come spring consider altering your cycles to encourage that root development. Besides, saving water is always a good thing.

Hatterasguy · #28 08-24-2010, 08:54 AM

Our neighbor loves crabgrass and we have been fighting it for years. It starts in her lawn and moves over to ours, last year it made the jump across the driveway and my dad had enough. We rototilled the area between the driveway and her lawn, mulched it and planted a garden.

Now we have a hard line and the stuff that jumped the driveway was killed.

cmbdiesel · #29 08-24-2010, 09:38 AM

Quote:

Originally Posted by SwampYankee

If someone could come up with a turf-type perennial crabgrass they'd make a fortune! It is amazing how heat and drought tolerant the stuff is.

I was shocked when I found this - http://www.seedland.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=Seedland&Category_Code=FS-CRABGRASS

Does open up another avenue to fight crabgrass....get cows

Free fertilizer too!

dannym · #30 08-24-2010, 10:02 AM

Quote:

Originally Posted by SwampYankee

I like to kid my FL friends that all they have is cultivated crabgrass.

It depends on what your expectations of a lawn are and your cultural practices (water, fertilization, pesticides, etc.). Organic, conventional (synthetic fertilizers and pesticides) or combination thereof?

I'm not real familiar with the warm season turfgrasses but some of the newer Bermudagrass varieties are damn nice with better cold tolerance (in parts of FL through the transitional zone they over-seed with turf-type ryegrass in the winter since the Bermuda goes dormant) than the old ones.

I use conventional fertilizers and pesticides.
I think I'll go with Bermuda seeds. But ironically, it appears the lawn is reseeding itself right now! It hasn't been cut in about 2 weeks now.

Danny