Well, it sounds as if the depth is right. How much sun do they get? Should be at least 6 hours for max. bloom, any less seems to cut down on bloom and make the plants a little "leggy".Do you fertilize? A small handful( 2tbls., or so) of 5-10-10, or similar(10-10-10- is ok) spread close to, but not on, the rhisomes, and a 1/4 cup of steamed bonemeal spread around the clump should be good.How's your soil ph? A soil test kit is cheap($15 bucks or so) Iris like a fairly "neutral" soil, but can stand it if it's just a little "off".A handful of garden lime around each clump probably won't hurt, till you get a test kit and can check for sure.Do this in early spring, before new growth starts, and again after they are done flowering. Do you know the variety of iris? Some of the older cultivars are a little "bloom shy", while others bloom their heads off...Hope this helps! ..Arlyn
