A new all-day charge of £4 will also be introduced in the road to try and make it more attractive for long stays.
The existing tariffs of 40p for up to half an hour, 60p for one hour, £1 for up to two hours and £2 for up to three hours will remain in place.
The changes are being introduced by Dorset County Council after few motorists used The Grove as a short-stay parking option while the Top o’Town car park, which offers all-day parking, is often full.
Project director for the Dorchester BID (Business Improvement District) Phil Gordon welcomed the move.
He said: “This is great news as the Dorchester BID and the Chamber of Commerce suggested this quite some time ago. We’re very pleased to hear it has now come to fruition.”