Over three years ago this area was growing an 20" diameter Silver Maple. The tree was removed and soon afterwards compost and sand were roto-tilled into the existing clay soil around the stump. Still no clue? Right.
Well after the tree was cut down, the stump was treated with Picloram (Tordon RTU) which is a herbicide used to treat cut stumps. If treated within 30 minutes the cambium layer picks up the herbicide and relocates it into the root system, effectively killing the roots and preventing sprouts. Because of Picloram's solubility it trans-locates readily through the root system. However it is also very soluble in the soil. Three years later the herbicide is still creating damage in broadleaved plants (dicots). It does not effect grass plants(monocots), and it doesn't effect all broadleaved plants. It has affected milkweed, potatoes, tomatoes, and goldenrod. It caused this leaf mottling and prevents the plant from blooming.
Hopefully, this will be the last year I see this and I can begin planting more dicots in the future. There have been reports of the same type of damage from using lawn clippings or compost derived from lawn clippings or hay/straw treated with Aminopyralid herbicides which Picloram is one. Visit the Compost Gardener.com to glean some more information about this possible problem. Hopefully this is not a problem in your garden.
The dreaded aminopyrallid strikes again. We've been there too about four years ago. Our potatoes look like your photos. I was told 6 years to get rid of it from the soil. Charcoal is supposed to help.
ReplyDeleteWow, this gives me pause when I think about using any non organic product. Who knows what lingering effects we have from all the chemicals we use.
ReplyDeleteThat's pretty dramatic! Janet's idea of using charcoal makes sense. Thanks for the info.
ReplyDeleteNever heard of that happening before. Hopefully this is the last year you see it and it doesn't cause anymore problems this year.
ReplyDeleteCher Sunray Gardens
Interesting Greggo. Last night at a Master Gardener meeting, the speaker recommended Tordon for treatment of stumps after you cut off volunteer trees. Then this morning, I read this from you....I'm staying away from the stuff, thank you.
ReplyDeleteWell I'm sure you have the same issues with tree seedlings that I do, and this product when used in a minimal amount will probably be safe. However with roses nearby I would shy away. The key is to keep it in the plant being treated and out of the soil because of its solubility.
DeleteI think what happened here is the stump was treated long after the first thirty minutes and was over applied.
DeleteThree years later!!!! Wow - that really shows how powerful some chemicals can be. We often forget how the soil feeds everything - but when it's poison that's getting fed, it really can open our eyes!
ReplyDeleteGreggo - it would never occur to the casual gardener that the impact would be so far reaching, and for so long. Thanks for sharing the information.
ReplyDeleteHow frustrating! I've heard of damage like this happening from composted grass but have never experienced it myself. Is there any way to speed up the process of leaching it from the soil? Would digging up the contaminated soil and replacing it with native soil from another part of the yard be helpful? You could fill the big hole with a pond. :o)
ReplyDeleteIt is scary how long chemicals stay active in the soil. Here is a link to some soil detox information that may be helpful to you. http://www.dirtdoctor.com/Soil-Detox-Newsletter-2010_vq3305.htm
ReplyDeleteOh, man! What a deal! The people who cut our tree down did not even mention the possibility of using anything to prevent sprouts. They did grind the stump, so maybe they don't use those things when they do that. I'm glad we dodged that bullet. I don't think I would have agreed to use anything like that, though.
ReplyDelete