I think .. maybe.. all that will fit somehow. Gallons always sound so big but I think the actual pots probably are smaller than I envision.
Peas are somewhat short lived and might be ok in the 2 gallon, and the ground cherry too.
Maybe 2 bell peppers in the 8 gallon. Maybe only one.
Cucumbers and cucamelon (?) in the 20 gal. Can you make something for cucumbers to climb on?
I think 2 gallon is too small for mature bell peppers.
I don't have experience with potted vegetables, just based on other vegetable experience.
