Regrow vs Regrown - What's the difference?

As verbs the difference between regrow and regrown

is that regrow is to grow again a part that has been lost, shed or destroyed while regrown is .

that grew, was lost or destroyed, and regrew.

To grow again a part that has been lost, shed or destroyed.

:Humans can not regrow lost limbs but some amphibians can.

:Deciduous trees regrow their leaves every year.

(head)

That grew, was lost or destroyed, and regrew.

The regrown weed is almost as big now as before I mowed it down.

(head)