Peony seeds have multiple dormancies. The easiest way to germinate them is to leave them outdoors and you should get germination within a year. Sometimes you get much faster germination. An unheated greenhouse should be OK. The offspring will not have the same flowers as the parent unless you have a straight species tree peony.

Some seeds will not germinate when kept at an even temperature even though it is the ideal temperature for that seed. When left outside and subjected to the natural temperature fluctuations they often will germinate quickly at a high percentage. Al