tillering

/T IH1 L ER0 IH0 NG/
verb
  1. 1

    To produce new shoots from the root or from around the bottom of the original stalk; stool.

noun
  1. 1

    The property of grass species to produce multiple side shoots or tillers.

Source: https://en.wiktionary.org/wiki/tiller, https://en.wiktionary.org/wiki/tillering