Pamela, I have never really tried to seed A. schubertii, but it has done a good job all on its own in my garden. I have it growing in a combination of sand and the native clay soil in Cologne on a sloped bed. It received more than 4 hours of sun most days, but it doesn't really get a baking in Summer, just a drought period right after blooming. Along with A. christophii, seedlings abound among the roses and take about 4 years to bloom for me. A. christophii is certainly the better spreader and often creates clumps where the seed heads have fallen. A. schubertii sometimes skips a year blooming for me and I only see leaves. I have the feeling it is somewhat sensitive to wet conditions during its rest and during Winter, as whole patches of seedlings will disappear come Spring. This could be mice, as well. Hope this helps a bit, Jamie V. Cologne Germany