According to MOBOT, it spreads by suckering, and grows to 1 1/2 to 2 feet. Other websites I found by googling it call it a ground cover, but say it can reach 3 feet. It sounds like you'd end up with a thicket of them, whatever the height may be.

Here is a link that might be useful: Missouri Botanical Garden on this sumac

most size estimates are at 10 years ...

presume at 20 .. it can be twice as big ..

size ESTIMATES are just that.. no plant really stops growing at some magical size ...

i would ...NEVER .. plant a sumac ... unless i had acres to cover ... and a need for one plant to do it ....

to wonder if any sumac wont spread by runners... is like asking such to change its genetic predisposition ...

ken

Thanks, so far, but I am looking for those who are actually growing this plant, and their experience.

If it sends out some/a few suckers during a year, that can be trimmed and maintained, so be it. If, they are like Itea or Aronia or Calycanthus, and send suckers some distance from the plant throughout the season... that is more of a problem!

My builder's landscaper is recommending five atop a retaining wall, and with taller shrubs behind the sumac. Some pruning is fine, but I do not want a thicket!!!

Comments?

Kitykat,
I suggest you read the thread that was so kindly provided to you by one of the generous responses to your question.
I think your comment is uncalled for, especially since you obviously ignored the help that was freely given to you from very experienced posters for your answer.
Read the thread if you want first hand experience.
Your welcome.

You can always do a forum specific search down near the very bottom of the main forum page. That's what I did and in the thread linked below, one poster referred to having to do a fair amount of work to keep them under control.

I know that for our Rhys typhina (staghorn sumac) which like R. Aromatica speads via suckers, we use a brush hog and mow the margins of the clump to keep it under control.

Here is a link that might be useful: Gro-low sumac

@butterfly4u...

Your SNARKY comment was uncalled for and hurtful!

I did offer 'thanks' to the first two responders, but requested further comment from those with hands-on experience.

(I certainly understand why some only lurk here at GW, unwilling to post!)

@nhbabs...

Thank you for the link you offered. It was the information I was seeking. When doing my search, I did not think of using the botanical name, since many/most gardeners are less apt to, and generally resort to common terms.

It also comes up in a thread on the perennials forum including a photo and comments on control.

Here is a link that might be useful: Combinations thread including Gro-low.