gardenglassgems said:@Hybridizer Those raised beds are amazing. 
What was the white stuff you put in them before the top soil? I plan to put in some more raised beds this spring. I am thinking they will be 4' x 8'. How far apart will you be planting your Iris rhizomes?
Thanks! Wood ashes. The bottom 6" consists of pulverized top soil, concrete sand, wood ashes, mushroom compost, and starter fertilizer. I till it all together, rake it level, then add 2" of topsoil into which I plant the new rhizomes. After planting, I put a 1/2" layer of mulch on the entire bed while being careful to keep the mulch 6" back from the rhizomes. This greatly helps to keep weeds down. When the roots hit the goodies underneath, they grow like crazy. My beds have an inside dimension of 4' 4" x 10' x 8" deep. The rhizomes are planted in a grid approximately 24" apart equaling 10 rhizomes per bed.
