I don't have much of a garden just a couple roma tomatoe plants, a couple of yellow pear tomatoe plants and two pepper plants. The yellow pear plants seemed to being growing crazy (they were almost at tall as me). One day I was talking to a friend while I was looking at her garden. I mentioned none of my tomatoes were changing colors. She was here for the bbq and said the plants needed to be cut back so the nutrients went to the tomatoes instead of the sucker branches.
I came home and cut back the plant. Can you believe with in a couple of days the tomatoes started to change color. Just this morning I picked 13 yellow pear tomatoes. My romas need a couple more days.