MAPLE WITH PESTICIDE AROUND
Hi,
Did not notice which pesticide.
Round-up for example, is usually foliar for absorbtion, but can penetrate thin bark, and possible on the "bark" area of a root.
Round-up is practically neutralized by soil. Garden labels allow planting vegetables etc. within a matter of days. It may as well be considered non-residual in soil.
In fact, wash dust of leaves of weeds before spraying Round-up - it is affected that severely by "dirty" material.
Round-up has no mechanism to get out of a plant.
Also, spraying a few sprouts on a large tree would be very unlikely to kill a large tree, although its good to get none into any wanted tree.
If you used a lawn weed killer, those have 3 main chemicals. 2 are especially foliar - 2,4-D & MCPP. The 3rd, Dicamba, is the naughty one that can move in soil with water, and is fairly residual.
If this was the case, a couple of years should have brought safety if you did not get radical with the dicamba.
Contact an agricultural supplier in your area that carries ACTIVATED CHARCOAL and ask them how to incorporate it. Country Club superintentents should be very familiar with it. If you have trouble finding a supplier, call a couple of the top golf courses and ask the superintendents where to get the product.
I recommended it once to a lady that fertilized her lawn and her neighbor's lawn for a favor - only problem is she accidentally used Casoron ( also sold as NOROSAC - Casoron backwards ).
If Casoron was your pesticide, it lingers for about 1 and 1/2 years.
It attacks areas of cell division - tops and tips of roots. Its bad to use around new plants because the backfill is often porous, and it can leach in, thus killing cell division at the end of the root tips.
Casoron does have a low water solubility though, so in fairly firm and settled soil, it will be on the top inch. If Casoron was your chemical, scrape away the top 1/2 inch of soil and get rid of it somewhere - make sure not to backfill around a new tree.
Also, consider contacting a Pesticides Class instructor of a local college.
Not sure if this was of help. I used to have an Oregon Pesticide Consultants License, but am not current on a few other chemicals that you may have used. But am certain about what I shared on the few above.
Mario Vaden
Landscape Designer / Arborist
M. D. Vaden Trees & Landscapes
Beaverton, Oregon