[cadalot]

What's that?

A key hole path going in from one side and form a C

 or

From both sides and form a H section to allow access into the middle area 

[Welsh Merf]

Nah - just one board across the middle of each bed. Should do the trick methinks!

[LotuSeed]

My raised beds are 4 feet across. Anything more than that and I'd have to do a lot of stretching and awkward maneuvering when adding compost/manure, weeding, planting and harvesting. My beds are spaced far enough apart so that I can fit the lawn mower in between em'!