cool season grass dormant or dead? how do you determine?

Discussion in 'Turf Renovation' started by roody2333, Sep 28, 2018.

  1. roody2333

    roody2333 LawnSite Senior Member
    Messages: 990

    ok so summer's ending and there's brown patches of lawn often assumed dead due to heat stress and then the decision is made to reseed those areas.

    How do you know for sure that the crown isn't still alive and going to green up around early Fall, therefore negating lawn repair?

    I read articles about 'dead or dormant' but will read more because what I read didn't answer what I was wondering which is, if the blades are dry and detached from the crown does that always mean the crown is dead? Assume this mainly for tall fescue, but perennial rye and KBG also. And assume insects or disease/fungus have nothing to do with it.

    If the crown is alive still and going to bounce back, the blades don't turn from brown to green, do they? I think I read they do but always though it'll send up all new blades.
    Or does it depend on how brown the blades are IOW if not fully dry and detached from the crown then I might expect those same blades to turn green again.

    I think it depends on how mature the lawn is too, if it's been there many years and has deeper roots there's a better chance it greens up in Fall.

    I'm just wondering how much, if any, still-alive grass crowns are torn up with slice seeders and dethatchers etc only to replace mature dormant grass with newer more fragile grass.

    Of course 'bad drought' and heat waves are a factor but assuming you know nothing about the past weather, can you inspect brown cool season grass and determine if it's going to bounce back?
    Is the best test to simply water it for a few days once cooler temperatures arrive?
    Also I've read if dormant over 4 weeks then it usually won't green back up, or if heavy foot traffic such as a narrow section often walked. And of course if fertilized while dormant with synthetic it probably won't live, same with spraying dormant with selective herbicide.


    there is an easy test you can do in your yard to determine the difference. Find a section of brown grass. Grab a handful of the grass and give it a quick tug. If it pulls out easily with no resistance, the grass is dead. The grass is just dormant if it resists or you have to work hard to pull the blades out of the ground.
    https://www.twinoakslandscape.biz/difference-between-dormant-and-dead-grass/
     
    Last edited: Sep 28, 2018
  2. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 15,022

    Not sure. Over thousands of years grass has adapted itself to survive droughts. Some will die. Grass will be thin. Most will recover by producing new roots from the crown. It is normal for grass to be grazed by sheep as in mountain pastures. When rains come--it will recover--usually.

    In a quality lawn situation--we do not tolerate thin turf. The customer usually wants thin grass restored to thick grass.

    I have seen big companies fertilize with synthetic and spray with herbicide--and yet the grass recovers in the fall.
     
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  3. jah

    jah LawnSite Member
    Messages: 20

    If it's not green by now, with all the rain that's come through the east coast, it is dead. I had the same thing this year. In July, as I looked at the lawn, the areas that I figured were dead, were dead. And no, brown grass blades do not turn green. The crown sends up new shoots.
     
    hort101 likes this.
  4. roody2333

    roody2333 LawnSite Senior Member
    Messages: 990

    me too, I think, I mean it was mostly a fungal issue but can see plenty of brown grass blades in the 4rd pic down from the top:
    https://www.lawnsite.com/threads/why-dead-sod.479829/
    4th pic down shows basically what most the lawn looked like, (the other 3 pics are obvious mostly total losses) but the 4th pic recovered good since June when it was treated, and watering was also reduced (and no night sprinklers) and now it's probably filling in with rhizomes and was overseeded, is dark green and doing good, not light green like in photos, and it still wasn't even growing or needing to be cut in mid June is strange even for a late-blooming KBG strain(s) if that's what was originally sodded.

    But I'm very hesitant to spray anything dormant or fungus damaged but it did ok and they used:
    escalade 2: 2,4-D, fluroxypyr, dicamba.

    Fluroxypyr is also even an ester

    and they put:
    Slow Release fertilizer and crabgrass, granular 4lb per 1000 sq ft, products: 19-0-5 0.29 barricade %50 SCU (TCS) (nitrogen, potassium, prodiamine)




    yea basically, if it aint green by now it's likely dead. But may be hard to have known a month or 1.5 ago when deciding to seed or not (better to seed earlier than later weather permitting not too hot)

    I was mostly wondering about the tug test and/or if brown blades turn green though but I think watering for a few days 1 or 1.5 months ago would be the most accurate test to know if it's dead or dormant.
     
  5. walkinonwater27

    walkinonwater27 LawnSite Senior Member
    from ct
    Messages: 316

    Roody you really need to try and simplify your posting, I can’t read a novel every time you post. Usually if you can slightly pull on the grass and it comes up easily it’s more than likely dead. It should still have some connection to the crown. Deeply yellow colored straw like grass is a good indication of possibly dead to . Any dormancy I’ve seen this summer is all green again and I’m in lower eastern ct, I used large amounts of potassium this season because of all the fungus, so that helps with recovery.
     
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  6. Delmarva Keith

    Delmarva Keith LawnSite Senior Member
    Messages: 472

    Assuming we’re talking about fescue, if a lawn needs thickening up come early Fall, do an overseed. If it thinned out from stress and some will come back, great but if it’s dead and you wait to make sure, it will then be too late to seed.

    If it’s KBG and the dead or thin areas aren’t enormous, just fertilize and water and it will spread back.
     
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  7. wjjones

    wjjones LawnSite Senior Member
    Messages: 443

    What are some of the native grasses in your area?
     
  8. roody2333

    roody2333 LawnSite Senior Member
    Messages: 990

    I don't think any really, being the border of the transition and cool season zones, causes cool season grasses to still get burn spots even with irrigation (especially if mowed short), and irrigation can lead to fungal issues from humidity creating a riddle of which stretches of weather to water during to prevent burn but when not to water to help avoid fungus. Someone said they core aerate in Spring and I think they spray potash also helps against fungus but I'm afraid to aerate in Spring and get crabgrass since I'm trying no-PreM now.
    Most lawns are tall fescue though, some are a mix of rye and Kentucky blue (must sprinklers for KB though).

    I'm just realizing there are a decent amount of solid zoysia lawns though, which technically is also a transition zone grass. Some zoysia lawns have what looks like patches of Fescue here and there growing taller than the zoysia, maybe someone threw some fescue seed down at one point, or could be a grassy weed brought in by a mower.
    Others have patches of broadleaf or grassy weed /crab/foxtail possibly from over-fertilizing, or someone using herbicide not suitable for zoysia, or from never aerating thatchy zoysia. Zoysia seems to handle the cold just fine though and many are near perfect solid zoysia.


    --------------------


    I'm running a small test to help determine if brown fescue sometimes/ always / never = dead grass/dead crown.
    Of course it matters if it was never irrigated and mowed short, young lawn, severe drought and heat, fungal, insects, over-fertilized etc.
    This lawn is probably none of those examples though, it's irrigated and mature, and is seeded about yearly by the fert company (which is probably a simple single pass of core aerator and a tad bit of seed, and they leave granular fertilizer all over the sidewalk and gutter and driveway every 6 weeks not supposed to do that) , but I don't know what their watering schedule is but I think it's at night time like most people for some reason do which can lead to fungus.

    Scalp mowed and bagged it at around 1.75". Can see a lot of brown grass was gently combed out for seed-to-soil contact with a tine thatcher, maybe lawn was over-watered maybe it wasn't watered enough. I purposely left a couple spots as-is and didn't seed those spots nor aerate them nor thatch them.
    Some of this brown grass is so detached from the crown (if it's still alive,,,will see) that I can blow it out with a backpack, some is a bit more attached.


    I will post back if the brown grass turns green again or if the crowns send up all new growth but even if the crown is still alive doesn't mean all brown grass in various lawns is the same scenario.

    dead or dormant (5).JPG

    dead or dormant (4).JPG

    dead or dormant (3).JPG

    dead or dormant (2).JPG

    dead or dormant (1).JPG
     
  9. phasthound

    phasthound LawnSite Fanatic
    Messages: 5,508

    All cool season turf grass originated in Europe. They have been improved over the years by breeding new cultivars. Several Universities have their studies evaluated be The National Turfgrass Evaluation Program (NTEP)
     
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  10. wjjones

    wjjones LawnSite Senior Member
    Messages: 443

    But some areas have more common native species that do well in some climate zones but not as well in others. Here in Tn there's alot of fescue, orchard grass, etc. I wasn't sure if he could overseed some type that would do better in his area.
     
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