Tree of Heaven Removal

Hi Permaculture,

I recently cut down a Tree of Heaven that was about 12 feet tall. At the time, I didn’t realize what it was—it was growing within the ficus hedge on my property.

Since then, I’ve learned it is a Tree of Heaven, and every 3 to 4 weeks I’ve been pulling up shoots that keep sprouting around the base of the small stump.

I’d like to fully eradicate this tree. If I decide to use a herbicide, is there a risk that it could damage the roots of my ficus while targeting the Tree of Heaven?

Thanks in advance for your help!