Ann, Where I was living we have a a clay type soil; gets very hard when dry and doesn't drain very well. In the bed where SDC was planted I dug up all the grass and some of the soil. I then filled it with soil from the corners of the horse pasture where the rain washes all the manure and such to. I also added perlite for drainage. I mixed it all together with the soil already there. When I would plant a daylily I would add pinebark to the hole. This spring before I remulched the bed I top dressed the bed with alfalfa pellets, milorganite, slow release fertilizer, chcicken litter (the processed kind you buy in a bag), epsom salt, and I think a little ironite.
Now all my beds are just pine bark (dime size pieces) and sand mixed together with the added amendments. If I ever have to amend soil in a bed again I will just add pine bark and till it in then add the admendments in the hole when I plant something and top dress the bed.
It could be that it changes color with the Ph of the soil, sort of like hydrangeas do. I keep mine around 6.5 which is what daylilies like.
