Safe travels Ginny!
Deb, I stumbled on something by accident last fall when I was planting bulbs. I had a boogie board that the cover had fallen off. I had made a brand new bed with lots of fluffy soil. I was pondering laying a piece of lumber down to keep from mashing the soil, but I saw the Styrofoam and tried that. It worked wonderfully. I had to start in the middle and work my way out to keep from mashing newly planted perennials, but it was worth it.
Love the irises, hope you get you rain to water them in!