60 Gal. Basket Weave Rain Barrel with Integrated Planter and Diverter Kit

It's 16 inches at the base and top expanding to about 22 inches in the middle. I've elevated my three rain barrels like in the picture with three 16X16 concrete squares to gain a little elevation for moving the water collected to an area about 50 feet from this barrel. The built in flower pot (not removable) works well provided you place a few stones near the drain to prevent the soil from washing out.

Possibly some PVC primer and then PVC cement in that area. It won't just hold with that and I'd suggest using or creating some sort of support strap or belt around that area to keep the unit from splitting again after you've sealed the unit with the PVC cement.

You have to water the plant separately and there is a drainage hole on the side.

Not that I can see. Looks like it's molded and assembled as a solid unit. Suggestion maybe remove the bottom drain and try flooding the unit from the input on top to try to flush it out. Perhaps a bleach solution if there is any mold growth?

No. It does not have a flat back

Since you have to drill the hole for the diverter hose you could put it in the top where the planter would go and maybe take the chain down to it. There is a drainage hole on the side of the planter area that would have to be plugged probably. I guess it would just overflow at the top when it’s full though since it can’t go back down the gutter plus having that open hole could allow mosquitos in.

Yes That is how I have it installed.

This barrel is not guaranteed to be BPA-free.

I’m not an expert but looking at mine, I think you could connect them with another hose at the top. I would have the second barrel a little lower so the hose will be downward some. Then when the 1st is full it just overflows into the hose connected to the second barrel.