don't let the grass grow under (one's) feet
Be continually active; do not stand still or be idle (thus giving the grass a chance to grow where you're standing). Don't let the grass grow under your feet, kid. Get to work!
don't let the grass grow under one's feet
Act now, don't delay. For example, Write your applications today; don't let the grass grow under your feet. This expression alludes to waiting so long that grass can grow. [c. 1600]
don't let the grass grow under your feet
Act with dispatch; don’t delay. This expression dates from the sixteenth century. It appeared in print in 1607 in Edward Topsell’s natural history, Foure-Footed Beasts (“The hare . . . leaps away again, and letteth no grass grow under his feet”).