Sumac and Lilac

(Question)

Hi,

My neighbour has a sumac that is invading my property in a horrific way. I am constantly pulling out roots that are at least 8 ft long. It is also bringing wild onion onto my property. Is there anything I can do?

Secondly, I have a lilac bush that has tiny leaves and really pathetic blooms that I would like to get rid of. I was just going to cut all of the branches down and dig out. Any recommendations?

All help appreciated.

Laura

(Answer)

Sumacs (Rhus spp.) are woody plants that have the potenial for forming large clones. They vary from short to tall, they grow in average to poor soil, and they thrive even on slopes. Sumacs spread by underground rhizomes which are  horizontal underground stems that put out lateral shoots and adventitious roots at regular intervals. As a result, Sumacs have the potential for forming large clones.

Unfortunately, there are few things that will stop its inevitable spread however, you can slow the spread by creating a physical barrier between you and your neighbour. If possible, dig a trench and sink plastic or metal as deep as you can. This won’t completely halt the movement of the rhizomes but it will slow them down. Meanwhile, for shoots in the garden, the only treatment would be to excavate around the invading sumac rhizomes and rip them out. Weekly mowing can control the rhizomes that make their way into the lawn however, mowing results in a loss of apical dominance , resulting in resprouting from existing buds on the cut stems.

If you are determined to losing the lilac then cutting back the branches and digging out the root ball is the way to go. If you would like to rejuvenate the bush the following is link with helpful suggestions: Lilac tree near end of life Without knowing your zone, sun exposure, soil type it would be difficult to recommend any alternative shrub.

Good Luck