I have been gardening in containers for 30 years and have discovered that no matter what kind of container whether it’s plastic, grow bags or whiskey barrels, if I used plain potting soil they dry out way too fast and more importantly the roots get too warm, are much more prone to wilting and have to be watered 2 or 3 times per day. I started mixing the potting soil half and half (more or less) with regular garden dirt and the roots always stay cool and I only have to water once a day. The plants thrive even when temps are in the upper 90’s. I live in zone 4.
I have been gardening in containers for 30 years and have discovered that no matter what kind of container whether it’s plastic, grow bags or whiskey barrels, if I used plain potting soil they dry out way too fast and more importantly the roots get too warm, are much more prone to wilting and have to be watered 2 or 3 times per day. I started mixing the potting soil half and half (more or less) with regular garden dirt and the roots always stay cool and I only have to water once a day. The plants thrive even when temps are in the upper 90’s. I live in zone 4.