Killing woody plants (like trees and shrubs) requires an herbicide formulated for woody plants. Brush B Gon is one such product.

Some people have reported good results will doing it in the fall (when the plant is storing up reserves in the roots). Make a fresh cut to expose the cambium layer (the green layer just under the bark) and apply the herbicide to that area.

Esh Thanks !
I am at my wits end! I wish my grass grew as well!
Thanks again!
Marcia

I'm not sure what you're asking. Do you want to kill off your beautiful sumac tree?

Not really, just the other 1000 that it has growing on it's roots! If need be, the big one also.:-((
Got any ideas?
marcia

You likely will kill the parent tree if the babies you wish to kill are suckering off its roots. Herbicides translocate throughout the conjoined roots systems.

Turn the area underneath it into lawn and mow it. Or just mow it. It's easy and effective. Very, very few woody plants can handle that kind of continuous, radical pruning.

Or turn the area into a sumac thicket. That in itself looks beautiful.

You don't actually have to "turn" the area into a sumac thicket. If you let the mother tree live, the babies will follow. They turn themselves in the saplings you want to get rid of.

I can't let them grow,
The mother tree is on the edge of a rock garden. It's within in the rock garden area where all the little ones are growning.
PROBLEM IS: my septic tanks are in that garden. The garden hides the tanks from view, and there are a couple of small bushes, and some flowers, but if I let it go to a thicket, the tanks will be damaged along the way. $$ for new tanks isn't in my budget. I bought the place 2 years ago, and not knowing what was weeds or flowers, I let it 'go' last summer...thus the little sumacs got a good hold on growing.
This year, I got it weeded, and cut the saplings, but I now have 3 times as many growing. I'm out there every week, but those little guys are determined to grow! I am sure If I had planted them, they would have died a long time ago!
I took a spray bottle with round-up and sprayed most of them. They are turning yellow, but I am afraid the roses, etc, will die too.
Thanks for all the help! It really is appreciated!
Marcia

Those who are amazed that you would want to remove your sumac tree have not lived under the curse of one. While they are fast growing and have wonderful fall color, it is impossible to keep the tree from completely taking over. I did have good luck removing one (thousands) in my yard. I cut the large tree down to the ground and then dug around the stump to the point where I could cut the roots and remove the stump. I made cuts into the ends of the remaining roots and applied large amounts of Ortho brush be gone to the exposed root ends. I left the "pit" open and repeated this process a couple of times. It has now been 5 years and I have not seen any signs of trees from sucker roots, now I just have to fight the seedlings starting from seed by birds from others still thriving in the area. While this was a huge project it was worth it. GOOD LUCK!!

Sumac is one tree that I'm seriously considering using herbicide for. I think I'm getting ready to go the Brush-Be-gone route. It is worse than anything else I've ever struggled with, including Bermuda.

http://pleasantvalleyconservancy.org/sumac.html

I have found that suckers can be control with a rotary mower. If they are cut back enough they eventually give up.

Contrary to popular belief, it s NOT necessarily ALWAYS true that trees damage a septic tank. I've never lived in a place with septic problems and never lived in a place that didn't have trees growing on the septic tank. I've also known some septic tanks that had no problems until a tree was removed.

However, I'll admit it *IS* a risk. In my opinion a bigger problem, trees do make it harder to get at the tank for maintenance.

Using herbicide to kill the sumac suckers would kill the parent tree.
If you want to preserve the parent tree, you would have to do it the slow, manual way. (Or maybe pave over the area around the tree or something. Probably not good for the septic tank either.)

Killing the Parent tree is exactly what I want also. I've been fighting those nasty little suckers for 15 years & unfortunately, they also can & do grow through a crack in concrete too. I finally got so sick and tired of them I'm digging up each root I can find & will be re-growing my lawn because the roots & new growth of the baby trees have ruined my lawn too. So I will not take any chances on these little suckers growing through my new lawn.

I've been dealing with Sumacs for 20 yrs, and the only way to get rid of them is to dig 'em up by hand, including all roots & rhizomes, until there are none left. It can take 3+ yrs if you are thorough in your work. The big problem is, some go straight down more than 2 feet deep!!! They grow fast & furious, and criss-cross every which way. Only small pieces remaining in the soil are needed to sprout a new little sumac. You need to keep digging up every day, or else all new sprouts will take over and you'll be in more of a mess than when you started!!!. These do seem to know when they're being threatened, and work double-time reproducing!

The following things DON'T WORK!!! because they don't kill the plant growth below the ground level:

Roundup, cutting, burning, roto-tilling, pulling out new shoots. If all the rhizomes aren't removed, then the plants will survive and THRIVE! Whatever is missed in one year needs to be dug up the following year. This year I am experimenting with using copper sulphate on the deeper rhizomes (those going straight down more than 1 ft deep) to see if it kills them. I mixed 15 ml copper sulphate in 2 liters water and set up a slow drip right on the offending rhizome… hoping that gravity pulls the cs solution vertically downward around the remainder of it. I'm leaving the hole uncovered, flagged it and noted so next year I'll know if it has worked or not. The copper sulphate will kill ANY roots that contact it, so don't just spread it around willy nilly!!! It's toxic stuff. Handle with care. It stays active in the soil, so could pose future problems with other plants that are growing where it remains in the soil at whatever depth it's at. I believe Sumacs are one of The Hardest Plants to get rid of and not ruin the soil in the process. It's all grunt work, by hand, each year 'til you, or the Sumacs, win.

Gosh, it's been a summer of thread bumping.
I'm sorry if generic roundup/glyphosate couldn't kill sumac, it wasn't being applied correctly. And/or the "Mother plant" wasn't being killed and was just sending out other shoots along the root paths of the old ones. Using copper sulfate as a herbicide? Still a violation of EPA rules and a bad idea, but, hey, at least an improvement over the nincompoops who have recommended using non-dilute bleach!

(to the poster from 2011) And btw if someone's going to say glyphosate causes cancer, you might as well say red meat, dairy, certain phamaceuticals, and artificial preservatives do as well, since there's actually far more evidence connecting those things to cancer than the _horticultural_ use of glyphosate. Fortunately the scaremongers, like sumac shoots, tend to get "burned down" around here, and move on. They are less of an annoyance than they were a few years ago.

Glyphosate only kills the plants above ground, not the rhizomes below. So new plants will sprout!

davidrt is probably suggesting you use a more concentrated formulation of "Roundup"...glyphosate actually, as Roundup's patent has been off for 25 years or so. It works everywhere that people who can read labels do so. which is most places!

Glyphosate and triclopyr are by far the two most commonly-used chemicals for "brush control", in other words, for cut/treat applications to cut stems of woody plants one is trying to get rid of. Highly likely that what you are doing is spraying the sprouts as they appear, but with regular 2% solution, like what you'd use to kill grass or weeds. No, that dilution rate won't kill sumac, but a 30% to 41% solution-like it probably says on the label somewhere-will. Ya gots to read.

"like it probably says on the label somewhere-will."

Are consumer grade herbicides actually labeled for stump control though? It's been years since I bought one so I can't remember.

In any case if there were to be a "gardenweb tropes" website, one huge trope would have to be the "roundup resistant" plant. Ivy is "resistant". Glechoma is "resistant". Bamboo is "resistant". Ailanthus is "resistant". It's almost never right, it's just misapplication...missing surfactant, not enough, not right time of the year, etc.

The closest I've found that comes to actually being resistant is Smilax. However if you use a strong dilution with plenty of surfactant and a bit of 'special sauce' I devised...applied when they are in active growth in early summer...no rain for days obvious...you can get complete burn down. They will weakly resprout in the fall or the following spring, but if you do the same to those shoots, you will kill it off completely. Oddly there is a published way of killing smilax involving dipping the cut stems in a mix of diesel and triclopyr ester, but I'd rather not leave open containers of diesel and triclopyr sitting around my property!

I suspect bamboos are also hard to kill with glyphosate, but there you just begin to deal with the practical matters of how to treat the entire canopy without a terrible overspray damaging your entire yard. I do believe that, hypothetically, if you could swing the expense and mechanistic challenges of spraying a huge patch of bamboo with 8% roundup and sufficient surfactant, at a time of year when it was growing, it would die. I guess the helicopter rental kind of drowns out the cost of 5 gallons of Rodeo LOL.

Heh, DNR has been copter-spraying big big patches of Phragmites up near here, on W shore of Green Bay, all the way up to Marinette. Probably Aqua-Neat or similar non-surfactant-glyphosate.

One that has eluded my every attempt at killing is a certain patch of field bindweed at a site I used to manage. That stuff comes up from a big potato-like tuber, so has plenty or energy to draw on, to replace whatever above-ground part you hit with the spray. I guess i never ventured into imazapyr territory or anything like that. But it did appear that while I could, with repeated sprayings, more or less get it out and keep it out of the beds themselves, the main plant network really, ran all throughout the surrounding turf. I wasn't going to beat that!

Our property lies adjacent to a sound barrier wall. On the other side of the wall there are many sumac trees. The roots are branching into ourcyard and actually growing under our driveway and sprouting up onnthe other side of my driveway. I am afraid the roots will ruin the concrete. I pull them up but it is a continuous chore. I dont know what to do because it is impossible to cut the trees as they are along the highway. Any suggestions as to how I can kill them?

To put it bluntly, if you live anywhere within "sound barrier land", the liability risks are too high for doing anything other than having a root barrier of some kind installed as close to wall as is legally permissible. (I'm sure municipalities must protect them with very strong easements) You could "do it yourself" by merely hiring an excavation company to dig a trench and installing a root barrier product you bought yourself...a landscaper (again, in a major municipal suburb where I presume you live) would probably charge much more for that service.

There are herbicides that can severely retard all plant growth in a given area of soil*...but again I think it's far too risky for you to use them, because if their activity spread unpredictably - and it does happen that way sometimes - and killed plants on the other side of the wall, I bet you could get in a lot of trouble with some bureaucrat. Even if it's a weed species like sumac...which is native after all, and thus could be considered 'planted' on the other side of the wall for supposed 'bioremediation' and 'wildlife habitat', etc. etc. Likewise, they could spread into a neighbor's yard.

Another approach to the battle might be to contact media, start complaining on facebook, etc. to shame the applicable highway authority into fixing the problem. In the DC area (haven't lived there in over a decade) there used to be a feature on the local news called "Seven on your side" that took complaints of Davids vs. Goliaths.

I'd always assumed those walls must have huge poured concrete footers and it's surprising to me this is an issue. Does anybody else living near one experience this? I wonder if the footers are in some way already cracked and compromised.

* - and of course, using them would preclude you from growing anything in the area, too

Now, OTOH,

spraying the individual sprouts with properly prepared glypho/roundup and letting them die before cutting, is more sensible than merely repeatedly cutting them. You will at least get some localized kill back of the root system that will slow down the spread, at least. Rather than completely stop it as something like imazapyr could do.

Dale Hadley, go to google and punch in otoh

Dale, OTOH is internet shorthand for "on the other hand."

Not all sumacs are alike, not all sumacs spread (the rope-like roots of those that do are called "ryhzomes"), and those that spread are a gardener's nightmare. I have only come up with one proven solution to getting rid of them, and that is by digging up and removing every single inch of rhyzomes by hand. This has been proven in Eastern Canada and the USA where sumacs are an invasive species. Roundup only kills the plant above ground; ditto for burning. Cutting (eg using a lawnmower) encourages spreading. Rototilling spreads the pieces of rhyzomes around where they will take root happily. There IS a herbicide that must be applied to the rhyzomes that will kill them, but since you have to dig them up to do so, you might as well just remove them. That herbicide is only legal for use in Canada by trained and licenced users, not the average gardener. It can be obtained in the USA, but as already said, you have to dig up the rhyzomes to paint them with it, so you might as well just remove them and not bother with the applicating of the herbicide. If you don't remove the parent plants, they will of course send out new babies to replace all you've dug up… Since the rhyzomes can go more than 2' deep, I doubt a root barrier would stop the spread. I am personally dealing with this exact situation right now. It is said that it takes 3 years of careful digging (removing bits you missed the previous year), to remove everything. So this is not a quick and easy project you must undertake. People will be happy to dish out free advice on this, when they see you on yours hands and knees digging, but virtually no one has any advice that is worth trying. Kneel and dig is your ONLY viable option. For three thorough, consecutive years. Tough if you have arthritis anywhere… All the best.

In the picture below, I have dug up rhyzomes on the right side, just to the left of the Maple tree in the middle. The orange flags indicate where I left off, and areas to be watched for regrowth, or rhyzomes that go deeper than 2'. There are 2 adult sumacs on the left of the house. The original parent plants died long ago, and I eventually cut them down. So I'm sure the existing 2 adults are now sending out lots of rhyzomes… There are sproutings in the next door neighbour's property, so unless I put in a root barrier, and it WORKS, the rhyzomes with just come back from his property. And no, he won't bother digging them up. The lawnmower technique is the most he'll do…

file://localhost/Volumes/LEXAR/DCIM/101ND300/DTC_8768.JPG

Photo isn't uploading… will keep trying!

correcting misinformation here gets tiresome

A correct dilution of pro-grade glyphosate with the proper surfactant...applied at the right time...will absolutely kill a spreading colony of Sumac for good. I've done it myself on the wetland part of my property.

Maybe it's harder in some chilly part of Canada where the plants are metabolizing more slowly or whatnot...I'm speaking to general conditions in the CONUS. Or maybe you can't get pro-grade GlyPh in Canada...I thought it was entirely banned there for consumer use in any grade, 'cause of the toxins'. [cue spooky new-age muzak]

I am not sure how a native species is considered "invasive"......but I guess that is neither here nor there :-)

Applying concentrated glyphosate directly to tree suckers or roots or cut back woody brush during the active growing season is a pretty well-established method of control. Ditto for doing the same thing with triclopyr, which I think is even more effective on woody stuff than glypho.

Rhus typhina is often planted along freeway verges here by the DOT - zero maintenance and great fall color.

What about 45% vinegar? pretty potent!