perennialize
suomi-englanti sanakirjaperennialize englanniksi
To return year after year as a perennial.
{{quote-text|en|year=2000|author=Tom Peace|title=Sunbelt Gardening: Success in Hot-Weather Climates|page=64
To make perennial.
{{quote-journal|en|date=June 5, 2007|author=Jim Robbins|title=A Perennial Search for Perfect Wheat|work=New York Times|url=http://www.nytimes.com/2007/06/05/science/05wheat.html