Hot Lips gone Mad

Not Mjr Margaret 'Hot Lips' Houilihan of M*A*S*H fame (actress Loretta Swit) but the Salvia 'Hot Lips' in our garden. I think it needs a little trimming in the Autumn. It's taking over that whole area of the triangle and swamping everything. Trouble is that it is so pretty we don't want to chop it back while it's still flowering.