Some of my tomato plants are greener than others
Some of my tomato plants are greener than the others of the same type. I planted "Mountain Fresh" tomatoes. One plant is greener than the others and has about 4 tomatoes on it. The others are a paler green with some flowers. Is 1 gallon of water per plant 2-3 times a week sufficient? Why is that plant greener? I fertilized all of them with chicken manure when they were planted in June and again yesterday. I have also sprayed them with Epsom salt water for magnesium.
You may need a soil test. There could be a microclimate that would cause the soil to be different in one area vs. another next to it. For instance, the location with the greener plant may have more nitrogen rich soil than those nearby. Also, if you have had a lot of rain, the nutrients may have been washed out of the soil. (But it might also be early blight, which flourishes in rainy weather.) Give them some time to see if they perk up after being fertilized. A soil test would let you know what, if anything, is missing so that you can fix it easily. Here is more information: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
As to the watering, this article should help: https://www.gardeningknowhow.com/edible/vegetables/tomato/watering-tomato-plants.htm