This is my first yr to plant tomatoes in the ground. I have had better success with this than with putting them in pots. I planted 4 different varieties and had limited success. So now I have 4 plants that have lots of new flowers but no tomatoes. I think the cool weather encouraged then to start up again. Should I keep watering in hopes of getting a few more tomatoes or is it a waste of water this late in the season?

Keep them!! They will not fruit in the hottest part of the summer, but cooler night temps will get them to start! Once they begin to set fruit, fertilize every 2 weeks with a good organic fertilizer. Water consistently but not soaking wet.