Another method of sumac control

My previous post on sumac dealt with large clones. Since large clones start as single plants, another approach is to kill the sumac plant before it becomes a clone, while it is still a single plant. The method I used was the treatment of the lower stems of intact sumac plants with the herbicide triclopyr (Garlon 4) in an oil (basal bark treatment). Garlon 4 is an oil-soluble version of triclopyr which when sprayed on the lower stem of a woody plant penetrates the bark.

The photo above shows two sumac plants treated 10 days ago. They are in the process of dying. Within another week their leaves will turn brown, curl up, and fall off. The whole plant will be killed.

I first tried this approach a year ago. I waited a year to be certain that no resprouts developed.

Although basal bark treatment can also be used on large sumac clones, it does not eradicate the clone because there are many underground rhizomes with living buds. After the above ground stems are killed, some of these buds start to grow and send up new shoots. Apparently the herbicide does not spread throughout the whole clone.

Since single plants do not form underground rhizomes right away, they are completely killed by basal bark treatment and are thus eradicated.

This technique is really very easy. No cutting is involved. Use a spray bottle that forms a fine mist. Take hold of the sumac stem and pull it toward you, thus exposing the base of the stem. Spray a band of herbicide a few inches wide up from the soil. With care, the herbicide can be confined just to the sumac stem area and does not reach any adjacent plants. In the photo above, the untreated plants nearby seem to be completely unaffected.

Getting rid of the sumacs when they are single plants makes a lot of sense to me. The photo below shows a prairie remnant in which individual sumac plants had been basal barked. The dying plants stand out clearly, and there is no damage to any nearby plants.