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hosenemesis

New thread on Purple Robe Robinia Locust

hosenemesis
11 years ago

Hi tree people,

I cut down my Purple Robe locust tree because it was sending root suckers into my neighbor's lawn, across my garden, and into my vegetable beds, as well as dropping yellow leaves into my pond all summer and rarely flowering.

This seems to have sent the roots into a shoot frenzy. There are literally THOUSANDS of shoots coming up everywhere. They are destroying my lovely little zoysia lawns, uplifting flagstones, disturbing the roots of my veggies and newly planted irises. I have been pulling up shoots for five months, daily. I'm tired. My neighbor has been mowing them down, but I am afraid he'll miss some and the roots will be fed. I go over there once a month to hunt for shoots in his ivy and weeds.

Has anyone managed to kill this tree? How did you do it? Do you think the roots will eventually die if I keep picking, or should I just Round-up my lawns?

Don't plant this tree in hot inland Southern California. Please. It won't bloom well, it will lose its leaves when temps get in the 100s, and it will destroy your garden and your neighbors will hate you.

Renee

Comments (15)

  • wisconsitom
    11 years ago

    Renee, locusts are, in the broadest terms, "broadleaved plants". As such, any of a number of phenoxy herbicidal preparations will do them in. It may take a few whacks at it, but should eventually work. That way, you needn't kill your lawn.

    +oM

  • denninmi
    11 years ago

    I second the suggestion to use a broadleaved weedkiller designed for lawns. The suckers will translocate the chemical through the entire root mass and kill it, but it will take a couple of applications. You can also, of course, carefully apply in other locations, avoiding desirable plants.

  • Embothrium
    11 years ago

    Liable to be a black locust rootstock you are dealing with and not Purple Robe.

  • katob Z6ish, NE Pa
    11 years ago

    Sorry to hear about your pain. I always liked the look of this tree but had trouble locating one and heard about the sucker problems.... (and the locust leaf miner problem around here) so never actually planted one.

    It's too late for you, but what do people think about girdling a tree like this and letting it die first before cutting it down? That's what I did for some alianthus and it seemed to spare me any sucker headaches.

  • strobiculate
    11 years ago

    A sight certain to quake the stoutest heart is not the locust leaf miner but the locust borer...the adult is fully an inch and a half in length and brightlt cilored in yellow and black, leaving holes in the trunk a half inch in diameter.

    Yeah, it be time to break out the 2,4-d...also known as a phenoxy herbicide. Girlding is okay...if you treat the cut with round-up or one the 2,4-d relatives...otherwise the suckering is likely to occur.

  • hosenemesis
    Original Author
    11 years ago

    Thank you for the encouragement. I will spray rather than pull for a while. The zoysia does not take kindly to broadleaf weed killers, but I can paint the stuff on the locust suckers.

    You know, I have an old regular Black Locust that my grandfather planted over 40 years ago, and I have never had any suckers. This led me to believe that locusts don't sucker here, which is why I took a risk on the Purple Robe. What a mistake. That rootstock is a whole different animal than my grandpa's locust.

    Renee

  • ken_adrian Adrian MI cold Z5
    11 years ago

    i have tried painting.. the glove method.. and dripping ..

    the only one you control completely.. is dripping ..

    both the cotton glove on a chem glove and the paintbrush.. themselves.. drip all over the place ...

    it doesnt matter what you put in the applicator ... someone once told me to dilute and mix both 2,4d and roundup.. i dont know about that ...

    ken

  • Embothrium
    11 years ago

    Variable suckering is seen in other species of trees as well. If the suckers you have now have the same foliage and thorns etc. as the suckerless black locust, then the suckers are black locust.

    There are lots of Purple Robe and other locusts here with few or no suckers.

  • modelafish
    10 years ago

    I have two purple robe and one golden locust that we planted when we moved in ten years ago. While happy with the rapid growth, shade, and blooms of these trees; I am constantly cutting down shoots throughout the yard. It has grown in to the neighbors yard, and he's allowed one to grow to a height of about 10 feet. If I apply an herbicide to the suckers that are growing in my yard, do I risk killing the one in the neighbors yard? Strangely enough, one sucker started growing in a part of the yard that was still open, and I didn't cut it down. It's now dieing on its own !
    (talk about a black thumb).

  • lucky_p
    10 years ago

    Recent discussions of Purple Robe, on another plant enthusiasts' list indicate that 'on its own roots' it's a suckering nightmare, far surpassing anything black locust ever even thought about...

  • lkz5ia
    10 years ago

    That is very exciting to think about

  • nvbasque
    8 years ago

    Can anyone tell me if the suckers of the Red Robe will ever bloom? We have a large area where we have let several of the suckers grow, we have trimmed them so they are trees and they don't bloom in the spring like the mother tree. TIA for any advice

  • tlbean2004
    8 years ago

    The suckers might not be old enough.

  • arbordave (SE MI)
    8 years ago

    Also, see Embothrium's post above (7/23/12) - suckers from the rootstock are probably black locust, not Purple Robe.