Answer: Unfortunately, the larger the plant the more root run is needed. In general, a five gallon bucket or even a half whiskey barrel is a better size for a husky tomato plant. Your planters might support some of the smaller leaf lettuces and early greens, radishes and probably a number of different herbs, but I think they are going to dry out too quickly to keep tomatoes and green peppers (and especially those water-loving cukes) happy. You might try a little experimenting with some of the smaller compact varieties intended for patio containers, along with using a waterholding polymer mixed into the potting soil, especially if you don't have an automatic watering system.
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