Hello, and thanks for contacting us.

Sumac clones itself through a system of rhizomes and suckers. Different strategies would be used if a) your goal is to limit plants to a defined space, or b) your goal is to get rid of it completely. The answers below assume that you do not want to use any organic or artificial chemicals whatsoever.

If your goal is to limit the plant to a certain space:

• Regularly (spring and fall perhaps) cut out the suckers that stray outside of their zone. You'll want to cut them out while they are small enough to be easy to cut. To do this, gently pull on the sucker and cut with a sharp pruner as close to the ground as you can. You might be able to pull it up from the soil a bit - this is good, as the more you can cut from the sucker, the better.  
• A thick layer of mulch below the area might make it easier to pull up the suckers going forward. It might also be helpful if you reserve a side that does not need to be cut out as aggressively, for example if the plant is in a corner and is allowed to grow back into the corner. This gives the plant a path of less resistance to grow, rather than the path that is continually being cut back.

If your goal is to remove the plant completely, you will need to mechanically remove as much of the plant and suckers as you can. Pull up on suckers and cut as described above, then dig down below the plant.  

I'm including a link to a blog article written by someone at a State Natural Area in Wisconsin about eradicating sumac.  The article was written in 2012 and is not our preferred .edu source but it has a great explanation as to how sumac grows:  http://pvcblog.blogspot.com/2012/10/sumac-eradication-techniques.html.  Note that the article mentions herbicides that might only be available commercially.

Good luck on your battle, and please let us know if you have further questions.

Hi Annette, 

Thank you so much for taking the time to send me such a thorough explanation! I am curious if I do limit the Sumacs to one area and try to pull suckers up 2x per year, would weed cloth at be useful ? Would native grasses compete with the sumac and maybe even win their share of land? Am I able to plant other plants in the area that sumac may still pop up?

Again, Thank You!

In my experience rhizomes will travel under landscaping fabric until they find a spot to grow. But it might be worth a try, and if you are consistent about removing the suckers you might just win the battle.  You might also add a heavy layer of rocks (or larger rocks on top of the fabric but only over the area you don't want the sumac.  If you add other grasses/plants leave a space between so you don't damage the new plants when working on the sumac rhizomes.  

Sumac can be quite invasive in other parts of the country - not as much in Colorado, but it depends on light/water in your yard.  If it's possible to reduce water to the sumac a bit, it could discourage more vigorous growth. If you're able to do this, choose plants that do well with little water for that area.

Hope this helps!