Yes, they can take a while to germinate. Some crosses will have close to 100% germination, but others might take an extra year or two. Last year when I planted my dwarf seedlings, I threw the used potting soil from the seedling pots into a pile near the seedling bed just to see if any more would germinate. At last count I was up to 20 new seedlings in that spot this spring.
With important crosses I hold the pots over another year or two, especially if I don't get a lot of germination the first spring.
