Eradicating Rhodondrons

monseiur

While visiting north west Mayo at weekend a relation of O/H who has a serious problem with Rhodondrons (well over 500 plants) was looking for advice on how to eradicate them permanently - digging them out is not an option.
I suggested that he should try injecting the trunk of say 30 plants first as an experiment, at near ground level with something like Grazon Pro - 10ml per plant perhaps ??
Basically use a cordless to drill say 8mm hole 75mm deep and inject weed killer undiluted and seal hole with some mastic.
Has anyone on here tried something like this or is it a hair brained idea ??
What's the best weedkiller to use and what's the best time of year to treat ?
Any other way of getting rid of this invasive weed?
He'd really appreciate any advise from some of the professional farmers on here
Thanks,
M.

Rows Grower

I've seen volunteer groups cutting them close to the ground level in Killarney National Park and that seems to work.
Your own idea will work too but will take longer and I'm not sure if it will do damage to the soil.

Birdnuts

monseiur wrote: »

While visiting north west Mayo at weekend a relation of O/H who has a serious problem with Rhodondrons (well over 500 plants) was looking for advice on how to eradicate them permanently - digging them out is not an option.
I suggested that he should try injecting the trunk of say 30 plants first as an experiment, at near ground level with something like Grazon Pro - 10ml per plant perhaps ??
Basically use a cordless to drill say 8mm hole 75mm deep and inject weed killer undiluted and seal hole with some mastic.
Has anyone on here tried something like this or is it a hair brained idea ??
What's the best weedkiller to use and what's the best time of year to treat ?
Any other way of getting rid of this invasive weed?
He'd really appreciate any advise from some of the professional farmers on here
Thanks,
M.

April would be the best time when new growth starts appearing. Cut and then inject roundup into remaining stems. AFAIK that is how they do it in the National Parks

longgonesilver

I think they cut and then immediately paint the stump with a half and half mix of round-up and water. The round-up is drawn down into the roots. They follow up with a spot spray of round-up and sticker the following year on any regrowth. With a subsequent spot spray as necessary.
The problem is the seeds are fertile so you have to keep at them for many years.

blackbox

longgonesilver wrote: »

I think they cut and then immediately paint the stump with a half and half mix of round-up and water. The round-up is drawn down into the roots. They follow up with a spot spray of round-up and sticker the following year on any regrowth. With a subsequent spot spray as necessary.
The problem is the seeds are fertile so you have to keep at them for many years.

I'd have thought drilling/injecting with Grazon would be more effective. My understanding is that Roundup works for leafy plants.

PoorFarmer

They seem to attack them in Killarney National Park in the late Autumn. Not sure if there is a reason behind this or just the fact that the National Park may be a little quieter. I know they arrange with some of the Mens Sheds around the country to help them out for a few days.
Maybe try ringing the park rangers office in killarney and see if they can enlighten you