black thumb

noun

: a notable inability to make plants grow : a tendency to fail as a gardener

Ever since I was a child, I was known for a really bad black thumb—I could not grow anything, and even worse, plants seemed to die under my supervision, even the plastic kind.—

Monica Bhide, Chicago Sun-Times, 13 Apr. 2011

In addition, I have a black thumb that can kill a petunia at 10 paces.—

Rob Pudim, Salt Lake Tribune, 11 Sept. 2009

also : a person who has a black thumb

Calling all black thumbs and those who are averse to flower arranging: Hardy succulents are the perfect solution for anyone who can't remember to water plants or who struggles to pull together a centerpiece. —

Good Housekeeping, 1 Sept. 2010

Even black thumbs will have a hard time killing plants in this self-watering pot. —

Wendy Manwarren, Redbook, 1 June 2009

compare green thumb

black-thumbed

ˈblak-ˈthəmd

adjective

Even a black-thumbed buddy can tend voluptuous tuberous begonias, which are happy in a less-than-light-filled home, or cultivate highly textured scented geraniums … —

Laura Kalehoff, Self, February 2008

The terrarium is ideal for the black-thumbed gardener who kills anything green. —

Mary-Liz Shaw, Milwaukee Journal Sentinel, 28 Jan. 2007