RickCorey_WA wrote: I wonder if the chicken manure was so concentrated or salty that plants couldn't use the water that was present? if so, it might leach out and become usable in a year or two. When the soil in a bed is marginal, I try to grow something really tough in it for the first few years, while the soil mellows and builds up a living population and organic matter.
Vermiculite crumbles in one season or less, I don't understand using it as an amendment for oudoor soil, or anything but seed starting. But many people do use it!
To hold more water, I like finely shredded bark and compost. For drainage, I like coarser bark shreds and grit-sized crushed rock (or VERY coarse sand, or very VERY fine gravel ... or expensive perlite).
If you already have soil with excessive coarse bark (excessive drainage), mix that in with purchased topsoil & compost for intermediate drainage.
If the bark is coarse or chunky, instead use it as a top-dress mulch to reduce evaporation. Or run a lawn mower over it a few times before mixing into heavy topsoil. Pine bark will HOLD water if finely shredded.
If raised bed walls are porous (wood or thin concrete or cracks between stones), the RB may dry out THROUGH the walls. A clear symptom of this is corners and edges drying out first. Line the corners or all of the walls with heavy plastic film (e.g. cut up the plastic bags that compost or soil came in).
Narrow, shallow RBs will dry out faster than big deep ones, but I have a narrow RB that has plastice under it to keep roots out, and up the walls part way. That stays damp longer than most of mine!
Continuous drip irrigation or a soaker hose does sound indicated.