What is this agressive plant?

Question: See the photo of the plant attached. It is popping up everywhere in my yard.

responder: Jacki D., Master Gardener Diagnostician Volunteer (Washington, Multnomah and Clackamas Counties) Oregon State University Extension Service Volunteer Metro Master Gardeners (http://metromastergardeners.org/) Replied October 31, 2024, 2:54 PM EDT
response: You are stumping the experts with this one! My first guess is one of the Clerodendrum shrubs. They are known to vigorously sucker via roots from another plant. Is there a mature plant in your yard or a neighbor’s? Next, describe the foliage scent when you bruise or crush a leaf. Is it distinctive? Strong? Familiar? What does it smell like? A nickname for Clerodendrum is peanut butter tree because of the leaf scent. Next, dig up one, and tell me what the roots are like (or provide a photo). Do you find it is connected to the other plants or is there a strong sideways root making you think it’s connected? If it is definitely a separate plant, it is more likely something that has grown from seed. If so, digging up each plant as they sprout will manage it. Do you see any sign of flowers or seed pods from this year or past years? How long have you seen these growing? How have you been managing them? If you regularly cut them down, when do you do that? I’m trying to judge how fast it grows, and why there’s no evidence of flowering. A photo of the yard so I can see if there’s a pattern might help also. Also include one of the full landscape, maybe including neighboring trees. I might spot the culprit. Note: if it is a Clerodendrom, management of suckers without damaging the mother plant is usually by manual removal. Avoid systemic herbicides, especially if a tree belongs to a neighbor. Once we identify it, we can offer removal advice.

responder: The Question Asker Replied October 31, 2024, 5:53 PM EDT
response: The neighbor has a Peanut butter tree at the fence line. I couldn't smell peanut butter on the mystery plant. Also,  the leaves look a bit jagged compared to the Peanut Butter tree. Roots of myste plant at bottom.Thank you!Loriann On Oct 31, 2024 11:54 AM, Ask Extension wrote:-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-Dear loriann, here's the response to your question: You are stumping the experts with this one! My first guess is one of the Clerodendrum shrubs. They are known to vigorously sucker via roots from another plant. Is there a mature plant in your yard or a neighbor’s? Next, describe the foliage scent when you bruise or crush a leaf. Is it distinctive? Strong? Familiar? What does it smell like? A nickname for Clerodendrum is peanut butter tree because of the leaf scent. Next, dig up one, and tell me what the roots are like (or provide a photo). Do you find it is connected to the other plants or is there a strong sideways root making you think it’s connected? If it is definitely a separate plant, it is more likely something that has grown from seed. If so, digging up each plant as they sprout will manage it. Do you see any sign of flowers or seed pods from this year or past years? How long have you seen these growing? How have you been managing them? If you regularly cut them down, when do you do that? I’m trying to judge how fast it grows, and why there’s no evidence of flowering. A photo of the yard so I can see if there’s a pattern might help also. Also include one of the full landscape, maybe including neighboring trees. I might spot the culprit. Note: if it is a Clerodendrom, management of suckers without damaging the mother plant is usually by manual removal. Avoid systemic herbicides, especially if a tree belongs to a neighbor. Once we identify it, we can offer removal advice.  Need to reply to the expert? Click the link below, or simply reply to this email. Click here to view #0158923 Jacki D., Master Gardener Diagnostician Volunteer (Washington, Multnomah and Clackamas Counties) Oregon State University Extension Service Volunteer Metro Master Gardeners (http://metromastergardeners.org/) We hope this response has sufficiently answered your questions. If not, please do not send another email. Instead, reply to this email or login to your account for a complete archive of all your support requests and responses.

responder: Jacki D., Master Gardener Diagnostician Volunteer (Washington, Multnomah and Clackamas Counties) Oregon State University Extension Service Volunteer Metro Master Gardeners (http://metromastergardeners.org/) Replied November 01, 2024, 11:12 AM EDT
response: You have photos of different plants. Compare leaf, bud and stem textures and arrangements. The plant you have in the followup looks like an annual of some sort, possibly a volunteer from bird food if you have a feeder. Stems are alternating rather than opposite, and smooth. If you have others, they will be easy to pull up, or leave one and see if it winters over and flowers so you can get an identification (remove before seed is produced if a weed).  The plant in the original question is probably Clerodendrum trichotomum, peanut butter tree. The leaves of this plant usually have smooth edges, but can be serrated, as some are in that first photo. Vigorous sucker plants often have bigger juvenile leaf forms and stronger colors than a “mother plant”. Compare the fuzziness of the buds and stems of your plants also. The Oregon Landscape Plants page, here, has a winter twig photo. If you keep the ones I think are Clerodenrum into winter, compare with it.

responder: The Question Asker Replied November 01, 2024, 12:30 PM EDT
response: One last question. How do I get rid of the small peanut butter tree starts popping up all over my yard?Thanks!On Nov 1, 2024 8:12 AM, Ask Extension wrote:

responder: Jacki D., Master Gardener Diagnostician Volunteer (Washington, Multnomah and Clackamas Counties) Oregon State University Extension Service Volunteer Metro Master Gardeners (http://metromastergardeners.org/) Replied November 01, 2024, 5:18 PM EDT
response: The root suckers are one reason some gardeners give up and totally remove these plants from their landscapes. A root is mostly likely to send up foliage if it is disturbed, as from digging for new shrubs, or if the mother plant is removed or in declining health. You need to manually remove the suckers. Rather than digging a big hole for each one, you might be able to reach at an angle with a sharpened shovel or other tool, slicing it off below the surface. It will be a sort of “wack-a-mole” task, needing to be done regularly. As I said, systemic herbicide can get back to the original plant, so avoid it. There are products for sale that are a sprayed hormone to slow sucker growth. Be sure to closely follow the label for application techniques and safety measures. I’m not sure what time of year it is most effective, nor how well it works on this type of shrub.