[dannieboiz]

Planning to build a couple planters out of redwood. The size is approximately 47x23x23. The most cost effective material would be 11/16 fence boards.

I saw some design that calls for the center vertical brace as shown in my sketch. is that sufficient to prevent bulging or do I need horizontal braces as well?

 

[HotRodx10]

It would probably bulge some on the long sides, unless you tie the sides together at or near the bottom. A board across the bottom (attached with stainless steel screws) or piece of heavy wire or allthread, will do.


The vertical braces will keep boards from bulging unevenly, but they probably won't keep it bulging at the bottom by themselves. They would make good attachment points for the ends of the whatever you use to tie the sides together, though.

 

[carpdad]

You can add horizontal brace to the verticals. One bottom and another bit below the soil.