The ideal approach would have been to use a brush killer such as
Ortho Max Poison Ivy & Tough Brush Killer (triclopyr) or Bonide
Poison Ivy & Brush Killer (ester 2,4-D) to treat the stumps
immediately after the trees were cut down. Known as cut-stump
treatment, the undiluted product is applied with a paintbrush to the
surface and sides of freshly cut stumps where it is absorbed into
the their vascular systems and translocated out to the roots. You
may have had a few re-sprouts, but nothing like you are dealing with
Some stumps don't sprout
The stumps could have been ground out the following summer.
Such targeted applications are more environmentally friendly since
the herbicide is only applied to the target, rather than broadcast
over an entire area.
Late summer and early fall are best for such treatments because
plants are translocating the products of photosynthesis down to the
roots for storage over the winter. They tend to absorb and move
herbicides down to the roots most effectively at time of year.
Although it is getting late, you might try a targeted brush killer
application. In this situation, you can apply the undiluted brush
killer with a pump up sprayer rather than a paintbrush. Do not pour
more into the tank than you will use since it is not good practice
to pour the leftovers back into the original container. Mow the
sprouts to create wounds, then immediately spray them with undiluted
brush killer. It may not work as well as it would have a month ago,
but it is worth a try.
Although this is a labeled application, be very careful since you
will be handling the concentrated herbicide. Be sure to wear long
sleeves, long pants, shoes and socks as well as chemical-resistant
gloves as recommended by the label.
Getting rid of bamboo
Insects in Mulch