Once a lavender plant has developed that woody, gnarly interior and begins to splay or spread open, it really cannot be rejuvenated. It should be removed and replaced.

You can delay that happening by routine pruning in early fall or in early spring but after a few years, it is almost inevitable that the plant will age into a form that is no longer appealing. Lavender farms here - and there are a lot - replace their plants on a 3-5 year schedule, depending on variety. And they get pruned hard twice a year.

Great, that's pretty much what I thought so makes me feel better about pulling them out.

Oh, gosh - I had an old lavender that had to be at least 10 years old, if not older, and it always did beautifully with a hard spring cut-back.