Built my raised beds 18 inches tall and figured out the real problem on year 3
Stood out there with a hose in July wondering why the soil at the bottom was bone dry while the top six inches stayed soggy, then it hit me that I'd been filling these things like flower pots instead of planting in the ground. Turned out the fix was mixing in about 30 percent native clay soil from my own yard instead of buying 12 bags of the fluffy potting mix from the store. Anyone else figure this out the hard way, or am I the only one who fell for the bagged soil thing?