I think you still need to feed them when the flower. Maybe give them more phosphorous and less nitrogen as they progress. I always kept feeding mine. I am not an expert though.

Ana, I continue feeding mine with either MG 24-8-16 about ever other week,and sometimes with my multiple compost aerated tea. Think I do get to much growth, but get lots of tomatoes so am not too concerned with the growth.
bernie

Flyingfish2: I know some people prepare weak fertilizer solution and use it every week. I want to use only organic and prefer using dry fertilizers. One time I used seaweed solution on newly planted tomatoes and it really made them growing fast comparing with others. Lukas nursery used to have ready seaweed fertilizer, but I don't see it there now.