don't let grass grow under one's feet

not let the grass grow under your feet- to not waste time or delay starting something - не откладывать дело в долгий ящик

He doesn't let grass grow under his feet starting working on the house. - Он, не откладывая дело в долгий ящик, принялся за работу над домом.

see also [за ним не станет]
Cf: [put sth on the back burner]