It is finally clear to me.
After feeling the remarkable heat radiating off the house the other night, I finally understand why I am a total failure at growing vegetables in pots on my deck. I’ve left the pots next to the house, basically frying them! There isn’t a way I could have watered those plants enough for them to thrive.
Maybe I’ll push a couple against the railing for the fall, then take advantage of that heat sink for the winter.