I'm using a couple 5 gallons for tomatoes. I' rather just use a 5 gallon bucket, but couldn't find them where I'm at. Selection is limited. 5 Gallon buckets, I recall, are a bit deeper than 5 gallon planters. I might be wrong, or they might just be shaped different where I'm at. I'm pretty sure you may have an extra inch or two, but you lose it in width/circumference.