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help with Crab Grass

Discussion in 'Pesticide & Herbicide Application' started by Marek13, Mar 19, 2008.

  1. Marek13

    Marek13 LawnSite Member
    Messages: 45

    I haven't been posting but been reading a lot here and I think I need your help on this one.
    One of my new clients has crab grass problem- she had some other LCO put Crabex (home depot stuff) last year but this didn't help -I saw her law last season as I have few accts on her street and she had about 25 % of crabgrass and rest was weak lawn.
    Now she does not want to cultivate/till it she wants to kill the crabgrass and then over-seed the lawn.
    What would you recommend? What product would kill the crabgrass (I guess home cheapo stuff wonÂ’t work)
    I was thinking or using aerator (the soil is as hard as rock) and then Thatcher to rake it and then overseed it and mix some starter fertilizer then lay a coat of some weed killer to take care of the crabgrass
    but I think I need some advise for you guys
    What would you do what product would you use.
    Her yard is about 3000 sq/ft how much would you charge for it.
    Thanks again
  2. TLS

    TLS LawnSite Fanatic
    Messages: 7,943

    Crabgrass that is there on the lawn NOW is dead. Not coming back. Rake it up, seed it, apply starter fert....RIGHT NOW! Apply Dimension after you mow the newly seeded grass at least once. That or try Tupersan.
  3. Whitey4

    Whitey4 LawnSite Silver Member
    Messages: 2,448

    I would power rake the dead crabgrass up. You can use a BlueBird set at the highest level for that. I would use a combo product like Barricade at the highest application rate this spring. Do it early... anytime from now through the first week of April. Get the crabgrass under control... then overseed in the fall. Barricade has the longest residual control of the pre-M's as far as I know, but you can't put it down too late or it could interfere even with an early fall overseeding.

    If she doen't want to wait until the fall, then about the only option I can see is to use a Tupersan combo product and over seed before April 15.

    Tupersan is expensive, the Anderson's 16-21-5 w/Tupersan is about $5/M compared to Anderson's 20-3-10 w/Barricade at about $2/M. With the Tupersan, you would likely have to do a second pre-M app with pendi or something later on, around late May after the new turf has been cut a few times. Tupersan does not have the residual that other pre-M's have.

    It's both better and cheaper to overseed in the fall.... but the customer has to be willing to wait... or pay.
  4. TLS

    TLS LawnSite Fanatic
    Messages: 7,943

    Hey Whitey,

    What are your reasons for NOT seeding the bare spots NOW? Why wait, conditions are perfect now. End of April he could have a real nice stand of grass instead of bare dirt which is prime for this seasons crabgrass to germinate into.
  5. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,708

    Whitey is right. If you seed now, the soil is cold. The seed will come up slowly; rye might be OK, but bluegrass will take about 4 to 6 weeks to be mowable height. Then you would have to put your Barricade pre-emergent control down, before the soil temp gets above about 55 degrees. The timing is very tight. Tupersan is costly. Odds are you will be seeding in the fall, again.

    Could you cover the bare spots with plastic tarps, treat the rest of the lawn for crabgrass and seed the bare spots with rye and add tupersan to those spots only? Difficult situation.

    In heavy crabgrass situations, it is best to treat the lawn at the maximum allowable rate (goosegrass), do it twice to be sure--seed in the fall and hope that the pre-emergent has dissapated enough to allow germination.
  6. Whitey4

    Whitey4 LawnSite Silver Member
    Messages: 2,448

    Well... everything has a caveat. I have two customers that will get mini-renovations this spring. One is a Cape Cod, with a walkway that splits the front lawn in half, about 1k of turf on either side of the walk. New customer, and one one side of the walk it's a disaster. Heavy crabgrass, and poor soil from a sewer line installation. It also has a large depression in the grade.

    I will agressively dethatch that side, regrade the soil using compost, composted manure, rough top soil and fine top soil. I'll slit seed and spreader seed it, using the Anderson's Tupersan combo product. Top dress it.... and I'm tempted to use Futerra rolls, but the customer doesn't want to spring for it. Cost would be another $90, plus labor.

    I'll do this in about 3 weeks. I HATE doing this sort of thing in the spring, but this section of lawn really needs all the help it can get. I'll use a 20 to 25% rye mix with KGB and some 10% tall fescue. I would not use that much rye in the fall, but I need some fast germination here. I would cut down on the rye if I was going to use the Futerra rolls, which are a fully decomposable compost blanket that dissolves into the soil... no paper pulp or other trash in it. Stuff runs about $50 per 600 square foot. I have one job in the fall that will use about 2.5k of the stuff. Great weed seed barrier, bird protection, erosion protection and acts as a moisture barrier to keep the seed moist.

    I'll just have to make sure I grade it out so that spring rain erosion doesn't run all the seed off the lawn. I refuse to use straw.

    The rest of this property will get the Anderson's .287 Barricade combo product. I wish they would spring for the Futerra rolls.... I would have 100% confidence in the renovation using it. Heavy spring rains could screw the whole thing up overnight. I'm even thinking about tarping it for a week and a half. I might do that if once I finish, a weather report calls for a 3" rain. But, I'm a little twisted.... I do stuff like it's my own house.

    So, spring seeding IMO is an option, but not a good one. Expensive, risky, and not near as effective as fall renovations. I will be over seeding the entire property come fall.

    Bare spots are a bit different. What I want and need to know, is why are they there? Lack of irrigation last year? Disease? Heavy traffic? I know why this lawn particular lawn is distressed. Lack of fert, poor soil, poor drainage. All things I will correct with this lawn. Usually, bare spots indicate a problem that needs more than just seed. Diagnose the cause(s), fix them.... then seed. If no apparent reason caused the bare spots, then it's time for a soil test. There is always a reason for failed turf and bare spots. Some problems are easy to figure, like grubs... others aren't so easy. Usually.... it's easy to diagnose.
  7. TLS

    TLS LawnSite Fanatic
    Messages: 7,943

    I guess I've just had better luck seeding in the Spring. Rain every other day (dry/wet cycle), cool and warm (cool/warm cycle), and better sun angle, all of which influence seed germination. I can never depend on this in Sept/Oct, and sometimes you'll get a frost and toast newly germinated seedlings in the fall.
  8. FdLLawnMan

    FdLLawnMan LawnSite Bronze Member
    Messages: 1,246

    Oh man, I have had the exact opposite results you have had with spring seeding. I have tried to reseed in the spring because the customers want it but have had disastrous results. The fall is the best time to seed, starting in the middle of August using KBG. University studies also show this. The seed won't germinate until the soil gets warm enough and then the crabgrass starts. Then just as the seed is getting established summer comes and it dries out. I hate perennial rye-grass, so I avoid it as much as possible.
  9. Whitey4

    Whitey4 LawnSite Silver Member
    Messages: 2,448

    Actually, that does not surprise me. Even though I am north of you, being on the coast puts me in zone 7, and you in zone 6. We get more spring rainfall than you, and because of the weather systems, we get torrential rains in the spring... much more that you do. LI never gets those early frosts you have to deal with. We will get at least two spring storms that will put down 2 to 3"s of rain an a couple of hours. That wrecks havock on spring seedings here.

    If I were in your area, I think I would do my fall overseedings earlier... last week of August time frame. Here, I would do the second week of September.

    But again, I think bare spots are indicative of an underlying problem. Turf fails for a reason. Traffic, irrigation, disease, drainage, soil composition, thatch, lack of microbial activity due to insufficient organic materail, nutrient deficiencies, the last two causing the turf to be unable to uptake nutrients.... pest problems, pet urine, even a shade seed being used in full sun.... there is always a reason. Turf fails because it isn't happy.

    If a particular strain of grass seed repeatedly fails in an area, there is often a disease at work.... replanting with a resistant variety to a particular fungus is sometimes all one has to do.

    There isn't anything inherently wrong with spring seedings, but generally, fall seedings tend to build stronger thicker turf. Spring seedlings will get stressed during the summer, while fall seedlings tend to remain unstressed, making for a thicker better developed root system. If early frosts are a problem for you, then my previous comment may not hold water in your area.

    Even the difference from one growing zone to another, 7 to 6 in this case, can make for big differences. What works best here may not hold for you.
  10. humble1

    humble1 LawnSite Silver Member
    from MA
    Messages: 2,519

    When i get motivated i have to put my before and after pics on here.

    This is where i have had good results
    Dethatch, Aerate 2 times, broadcast seed 1/2 down, slice seed the rest in two directions.
    Starter fert.
    The grass will grow in and be long way before the crabgrass can come in, mow it high 4" by the time crab starts to come in you could use aclaim i thing as long as it is 6 week old grass you would have to check the label. get on a program for grub, weeds etc. Start next year off w/ pre emergent.

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