Ragweed ID and Control

Asked May 18, 2015, 9:35 AM EDT

Is this ragweed and if so, how can we control large portions (20x30 feet) in our native wildflower meadow? Currently the plants are about 2-3 ft. tall, growing in full sun. Leaves (~4 to 5 inches long and ~3 to 4 inches wide) are opposite on the hairy plant stem. No flowers yet.

Baltimore County Maryland

6 Responses

It definitely looks like it could be Giant ragweed, but we can't tell for sure from your photo - if the leaves are arranged directly opposite of each other along the stem, it probably is.
We would suggest weeding it out.
If you feel you need to use a chemical, careful application of a product containing glyphosate would work, but you must follow label instructions carefully. It will kill any green tissue it hits. Also avoid areas with water or amphibian life.
cm

Sorry -- I meant to say in my earlier email that the leaves are alternate along the plant stem. See new photo 3 attached. Do you have any additional information on the ID for this plant? Thanks

We cannot make an accurate identification at this point. Let the plant flower for another identifying feature. It is possible the flower may be inconspicuous or not showy.
mh

Thanks for your response. I need to ID the plant before it flowers, since there are a lot of these plants in the meadow and I want to pull them very soon if this is an invasive weed. Are there any online plant ID keys you would recommend?

Success and good news!
Our native plant specialist took a look at your photo and said that your plants are Brown-eyed Susans. (Rudbeckia triloba).
cm

Thanks very much for ID'ing this plant!