I apologize for this delayed reply to your gardening question and hope it is still helpful to you.
I suggest you purchase a product containing glyphosate (one example is Roundup). Wipe the product on to the foliage of the maypop using a sponge type applicator and taking care not to get it onto the foliage of desirable plants. It will translocate down into the roots and kill the target weeds but reapplication may be necessary periodically as you generally don't get them all the first time.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
Q&A Library Searching Tips