Angelonia isn't supposed to need deadheading to continue flowering, but I have found it may take a break with few flowers open and then start flowering again later. I've never deadheaded it and it comes back. I did find that the white didn't do as well here as the dark blue. Haven't tried the pink or light blue. It's one of my favorites. I have to admit that my climate is way different from yours, but the references I checked, including Proven Winners, say it doesn't need headheading to continue flowering, FWIW.
