underroot

From Middle English underwroten, equivalent to under- +‎ root.

underroot (third-person singular simple present underroots, present participle underrooting, simple past and past participle underrooted)

1. (transitive) to dig or burrow beneath, especially beneath the roots of; (by extension) to undermine
   • 1986, David L. Hamilton, Maintenance Techniques for Interior Plants, page 7:

     These underrooted plants (especially in lower light levels) are your greatest concern.