I have two tomato plants on my patio. My cherry tomato plant is fine and producing little tomatos like crazy. But the early girl tomato plant produces flowers, they blossom and then fall off. ????

Excess nitrogen, low sun, not enough water, or too high of daytime temp. Any of these will cause the plant to not set fruit. There is a product called blossom set but it might not offset the above conditions if they exist.

It could be that you let them get a little too dry between waterings. If you've applied fertilizer containing nitrogen too late in the season that might be the cause. Personally, I'm betting on irregular watering. Lee Valley (leevalley.com) sells spouts for liter bottles that you might try. the watering is regular and consistent and will save you from remembering to get out there and give them a drink. You just fill the bottles up and poke the tops in the soil. The water is taken in as needed and you fill the bottles when necessary.