Mower damage to Trees

Discussion in 'Homeowner Assistance Forum' started by Catcher, Jun 19, 2002.

  1. Catcher

    Catcher LawnSite Member
    Messages: 166

    Any Arborists on this site?
    After the purchase of a ZTR mower a year ago I was trying to eliminate all push-mowing, weed-whacking, etc. Henceforth I was pushing my mower-deck closer and closer around the tree-trunks on my property. Well, like an idiot I've been scuffing the bark either with the deck or with the wheels. The other problem is that I've been putting a lot of weight on the surface roots of the trees, with the drive-wheels grappling for purchase between exposed roots and the turf.

    Now that the damage is done, I have started to stay away from the trees again to prohibit further destruction.

    I know that it can take years for the tree to die, how can one estimate the damage done to trees?

    What are some measures one can implement to aid the tree in 'healing' itself?

    Any ideas and suggestions will be welcomed.
    The trees include Cherry, Maple, Oak, Elm and some softwoods with a trunk-diameter from about 20" to 30".

    Thank you

    HOWARD JONES LawnSite Member
    Messages: 233

    I would recommend trying
  3. lawnstudent

    lawnstudent LawnSite Senior Member
    Messages: 472

    Under the bark of the tree is the cambium. The cambium is used by the tree to channel nutrients between the leaves and the roots. Every time you nick the tree base you remove bark and the cambium. Do this all the way around the trunk and you have girdled the tree. The more the cambium is removed the more you restrict the movement of nutrients between the leaves and the roots. Trees survive with a 1/3, a 1/2 or even 3/4 of the cambium destroyed, but you put the tree an risk. You restrict the trees growth. This is an open wound that can be an entry for disease or pests. Over time with enough damage to the cambium you can kill the tree. Best thing to do is mulch around the base of a tree so you do not risk further damage to the tree.

  4. LawnLad

    LawnLad LawnSite Senior Member
    Messages: 738

    At my house I spray a 2" to 3" band of Round-Up around the trunk and root flares of the trees. From 15' away you can' see it. My customers wouldn't tolerate me doing this to save time on line trimming, but at my house I can get away with it.
  5. Catcher

    Catcher LawnSite Member
    Messages: 166

    Thanks to all,

    yes - I have sprayed ~20" with roundup to give me some clearance. I am thinking of installing a 4' - 5' circle of pea-gravel around each base, to keep it easy to maintain (open to suggestions).
    That still leaves the problem with the surface roots. I'll probably haul some topsoil in to dress those areas as well.
    I guess my biggest fear/ worry is that these trees will die slowly over the course of the next few years. The actual damage around the trunk is not that bad, I have one or two trees where the corner of the deck took a good chunk of bark out, the rest of them have slight 'rubmarks' which I don't deem too bad. A lot of damage was done to the surface roots, mainly from having the drive-wheels 'chewing' on them over the course of a year or so.
    Should I dress any damaged areas with tree-tar or do anything else to the trees to avoid infection and promote healing?
    Thanks again to all.
    Any ideas and suggestions on this and also on care-free borders for around the tree-trunk are welcomed.
  6. lawnstudent

    lawnstudent LawnSite Senior Member
    Messages: 472

    I've not completed my hort degree yet, but the prevailing view is not to use tree tar or tree heal products any more. Let the tree naturally heal.

    The pea gravel may not supress the weeds. I prefer mulch to pea gravel.

    There are a lot of roots under a tree. You probably damaged two or three surface roots? I'd not worry too much about the roots. Its the trunk girdling that's the big problem. Damage the cambium and it's permanent. Sounds like you have not done significant damage to the cambium. Tree should survive. Your biggest risk is disease or bugs entering these wounds. Your doing the right thing with roundup and some kind of mulch. Good luck. Way to grow.


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