Mystery Dead Zone around Dead Black Locust Transplants

Late last winter I transplanted 6 volunteer black locust seedlings from one open pasture to another, in three sets of two. One pair survived the summer, the other two pairs died. Last weekend I discovered a dead zone around two of the dead saplings. In the attached pictures you can see the dead zones in the middle of tall green grass. The dead zones actually extend away from each sapling in an elliptical shape, downhill a few feet from each sapling.

I can only assume that the dead saplings are releasing some kind of biological chemical that washing downhill and killing whatever it touches. But the other two dead saplings didn't produce dead zones, and the ones that survived, along with the rest of their brethren in the original pasture, are surrounded by plenty of growth. Has anyone seen this before? I'm wondering what to make of it. Does it indicate something about black locusts that should be taken into account when planning a system? If killing grasses is your goal, could black locust saplings be a potential method?

This is my first time posting, since I thought this was curious enough to share. I will watch to see how long it takes the grasses to reclaim the dead zone.

Looks like eco terrorism to me. I think you elongated swath looks more like the result of and herbicide spray. Possibly from a hand pump sprayer on the other side of the fence.

Are you located in a region where black locust is formally, or informally considered invasive? As I'm sure you know some people can be quite passionate about invasive plants. I attended the university of Maine, the night after a guest lectured came to speak about invasive plants, two Norway maple where girdled in front of the Forestry building.

Just a thought.

As a forester, I have never heard of a plant of tree with Allelopathic properties as strong as what your picture is illustrating.

Hi Gordy and welcome to Permies. I have to admit - that looks very suspect. Never seen anything like that naturally occurring.

Our power company does that....every locust sprout from an old stump under the power line...in spite of our no spray signs, repeated phone calls and letters...the sprayers are told to spot spray and locust sprouts are evidently greatly feared. We mow twice a year but sometimes the locust grow faster than everything else.

The property is out in the country and the majority of the flora in the section that abuts the road consists of black locust, mimosa silk trees, trees of heaven, empress trees, and privet, so eco-terrorism doesn't seem likely (I'd certainly welcome any eco-terrorists interested in helping me destroy the privet). However, powerlines run directly above the two saplings. I also noticed a couple of additional dead zones in a non-grassed section by the road where silk trees were coming up and wondered what in the world might be the explanation, but those are also directly beneath the powerlines. So I'll be damned, it must be the power company. I will have to give them a call. At least maybe I can get a list of everything that they spray and dig it up before they come spray poison on my property.

As an aside, it's a little scary to imagine how much of the form of the landscape around us may be maintained by spraying. Not just lawns and landscaping, but I recall riding my bike on a path through a median in a city when they happened to be running sprayers over the grass in the median. This was a non-descript median in a run-down formerly industrial part of town, I always figured all they did was cut the grass in such places, but no, they were investing lots of money in herbiciding in order to avoid dandelions I suppose. I've also seen them spraying the side of the road on the exit of a minor highway where weeds were coming up between the cracks in the pavement. Now I must imagine that powerlines are vectors for industrial herbicides as well.

Anyhow, thanks so much for the replies. I would never have thought of this as a possibility.

This is good info to know, and a bit scary to think about.

I finally called the power company (Central Virginia Electric Cooperative) a few days ago and talked to the company forester. Learned the following:

1. They won't spray areas that are mowed.
2. They will spray any saplings in unmowed areas that will eventually grow high enough to interfere with the power lines.
3. They won't spray trees that appear to have been planted by the landowner (ie. saplings that are mulched and staked), even if those trees may eventually grow tall enough to interfere with the lines. In such cases they'll top the tree when it grows tall enough the threaten the lines.
4. The easement for the power lines is 45 to 50 feet wide, so they won't spray anything past about 20 feet from the center of the power lines.

My problem was that I stopped mowing the area and that my transplanted saplings appeared to be volunteers. So I'll have to put some thought into how to arrange the flora along the road. It appears that black locust trees can be pollarded, so I may replant some, mulch and stake them, and then pollard them once they get to head height.

Thanks for the help everyone.