Glyphosate, the active ingredient in "normal" RoundUp, is effective for just about any type of plant. The easiest way to apply it is to cut the tree down leaving a relatively level stump at or just above ground level. Then, apply concentrated (about 18% or more) glyphosate/RoundUp to the freshly exposed phloem. There is no need to treat the xylem (the middle of the stump). Regular RoundUp may work slightly better than the quick-acting stuff for this application. Don't use the premixed/ready-to-use formulations, because they will probably be relatively ineffective in treating stumps. You won't need much chemical, because you only need to place a ring of it right on the top of the stump. Doing it now will be fine, but don't wait until spring. When sap starts rising, the effectiveness of this treatment will be reduced.

Brush-B-Gone and the stuff for poison ivy and briars works too.

That distance is way too close for anything to be planted. You should definitely get rid of it.

The active ingredient in Brush-B-Gon (no e) is triclopyr. Like glyphosate, there are also other brand names too. If you use it, use it in a concentrated form also and apply just like the glyphosate.

Thanks brandon, jcalhoun for your suggestions.

Comparing to cutting down the tree and apply Roundup on top of the stump directly, is spraying much less effective? Do I have to spray the whole tree or just part of it?

Cheers.

i do NOT believe that RU is LABELED for a use that included spraying the whole tree ....

further.. there would be no way to control spray drift ... and the next thing we would know. would be that you would be complaining that the RU killed everything else in the yard for many feet around.. when in fact.. it would have been you.. using it in that manner ...

cut it down to about 3 feet ... start digging.. [only if you insist in removing the stump] .... using the trunk as leverage.. to find out where the next root to cut is ...

on my 5 acres.. i would cut it flush to the ground.. and apply the stumpkiller... RU in my case.. and be done with it ... i would not bother digging it up ...

IMHO ... trees do NOT harm.. INTACT ... pipes.. sewers.. foundations.. etc ... they take advantage of pre-exisiting conditions ... things that all ready have cracks in them .. otherwise.. they simply hit a wall/pipe .. and turn and continue ... obviously a septic drain field is an issue ...

use the products in the manner intended ... the label is there for a reason ... nobody sprays a 20 foot tree ...

ken

Hi Ken,

Thanks for your comment.

I saw photos of fully grown cotoneaster trees could be like 30+ feet tall and wide! I thought this one is still young'ish at under 20 feet, and could be treated by spraying it.

The main reason to get rid of it, besides of the potential damages cause by roots, is subsidence. My house is built on clay soil and building insurance companies want a lot more in insurance premium if there are trees very close to the house.

I shall get a tree guy to do it then.

Cheers,

Good idea.

He'll have everything to make it quick and easy.

Even if you kill the tree with chemicals you'll still need to cut it down and get rid of it. Unless you're good with a saw and ropes you'll have to hire somebody either way.

How big a cotoneaster gets depends on which kind it is and how it responds to the site. 20 ft. is pretty big as far as it goes, too bad it's in a spot where it is not working out.

Agree it should be taken down. You don't give your location, Peter, but unless you're in the Deep South Roundup etc won't be effective in winter temps. Plus as others have said, you'd still have to remove it.

My son and I recently cut down a 20' holly in the same sort of location. I was the rope puller, my son the cutter. We had it down, cut up and hauled to the street in about 45 minutes. So relieved to have it gone!! And used an electric chain saw.

Suggest you add location and USDA zone.

Rosie

"...unless you're in the Deep South Roundup etc won't be effective in winter temps."

Although that may seem like a logical conclusion, it's not really right. RoundUp works fine for this type of application (killing the stump of an evergreen or semi-evergreen woody plant) as long as temperatures aren't below around 40F. I'm not saying that it will be AS effective as if it were applied in the warmer fall months, but it will generally do the job.

I've used RoundUp in cold weather on plants with the leaves on. It works, but the effect is slow. When people say they've tried RoundUp and it didn't work, I always ask them when they applied it and if they watered it in real good. You'd be surprised how many people say yes to the latter. (Whether they did or not is another matter)
I had one customer tell me that if I wanted RU to work real fast I should mix it with diesel! These people breed AND vote!
I'd sure like to see a picture of this cotoneaster. I know some varieties get that big, but I've never seen any with an 8 inch diameter trunk and 20 ft. tall. Do you know the variety? Any volunteers? Sounds fun to grow.
Mike