[aimeruni]

No the containers aren't self-watering. The containers have holes in the bottom for irrigation, and I will be watering the plants myself. Also I did have one other question; you said using compost in bottom drain containers with the amounts I listed will be fine. Should I reduce the slow release fertilizer (i.e. osmocote) or keep it the same? Typically I use 2 cups of fertilizer (like osmocote) per 30 gallon batch. However, since I'm using compost if I were to keep the measurement at 2 cups, would it over fertilize plants? The main reason I keep asking this is because they are heavy feeders, so I don't know if I should reduce the slow-release fertilizer, or keep it the same with the addition of the compost.

The containers will be 45 gallon size; I can't really get away with anything smaller, without compensating the plant somewhat in the process, which I don't want to do.

I know because I grew two winter squash plants (one per container). One was grown in a 45 gallon container; the other about a 30-40 gallon container. While both plants were healthy, the one in the smaller container wasn't as vigorous as the one in the larger container, and it was noticeably smaller in comparison to the one in the larger container.