Both pots were started at the same time from the same batch of strawberry starts. They should have the same soil box. Both grew vigorously last spring/summer and got visited by deer in the fall. Both bounced back pretty well before winter set in. The left pot is very happy, the right... Not so much. I do recall the big pot having quite a bit of wilted leaf cover all winter, but don't think that was the case for the pot on the right. Maybe I didn't notice a late in the season deer visit that set the small pot back? Maybe the smaller pot got just enough colder than the big pot to kill some roots? Any other theories?
How hot and sunny is it? Could the black plastic pot get hot enough to harm roots, while the steel one would reflect more light and stay cooler?
We're zone 6a, so not that hot. They're in a spot that gets full sun for most of the day (morning and evening shadows, direct sun when the sun is hight in the sky. Last year both pots thrived, but only the larger metal pot really came back post winter.