perennialize

verb2

1. •
   To return year after year as a perennial.

   • I recommend spending your bulb budget on bulbs that will perennialize in the garden, and if you need big tulips, purchase a bunch from the local florist. — 2000
2. •
   To make perennial.

   • The quest here is one of several around the world, to perennialize everything from sorghum to chickpeas to sunflowers. — 2007