There are usually a few new shoots/branches on 'Siam Queen' that I can pick for stir fry (as far as I can tell, only leaves on the branch that's actually budding/blooming taste bitter), so I mostly let it bloom away... it does have such big pretty flowerheads! There are some recent Thai basils that are grown really for their blooms, not so much for culinary use ('Magical Michael' is one).
