Funny really you asking this now... I've had lavender hedge edging in my front garden for close on 20 years - not the same plants but regularly replaced cuttings of same to prevent it getting too woody.
Anyway I am redoing my front garden and decided to do away with the lavender. Dug it all up last weekend!! Some went to new homes with friends, some to the compost heap. There was nothing wrong with it really but I felt I - and the garden - needed a change.