Q : how to trim / prune sea lavender

[polaris]

I have a sea lavender bush in the front yard that is becoming unsightly. the lower foot or so of leaves and branches and leaves have turned brown (left side of the bush as seen in the photo). I looks to me that if I were to prune it I would end up removing most of the bush (on the left side of the photo) . The sea lavender is in its fourth year and has grown about 3 times its original size. I wonder if it is time to do a serious prune and bring it back down to a smaller footprint.

thanks
-Bob
San Diego, CA

 

[Sheal]

I would pull all the dead foliage by hand and prune off the dead or dying flower heads.