Ask Extension is a way for you to get answers from the Oregon State University Extension Service. We have experts in family and health, community development, food and agriculture, coastal issues, forestry, programs for young people, and gardening.
Q: I am dealing with poison oak growing in a stand of trees: Douglas firs, big-leaf maple saplings, and others. I have tried manual control and was unsuccessful. What would be the safest topical herbicide to apply to the leaves and stems while minimizing damage to the surrounding trees?