There are many dwarf varities of known blooming cultivars so you need to see what gaden centers sell, then do some research as to their plant zone, like weigelia. I like Potentilla Fruticosa "K. Dykes" which blooms through the summer, yellow.

Here is a link that might be useful: Propagating Perennials

I know you are looking for something other than azaleas, but I just had to tell you about our experience. I live in Dallas where the soil is not appropriate for azaleas at all. We moved into this house 4 years ago. The previous owners had planted azaleas all along the front of the house. Our house faces north as well. The neighbors have told us that the previous owners removed all the dirt and had dirt that was good for azaleas brought in. I never do a single thing to my azaleas and I can't even tell you how pretty they are! Our house is the house where all the neighbors bring there kids for Easter pictures just to get them in front of the blooming Azaleas (Easter was too early this year though). I once had the Dallas Arboretum come to my house to tell us what we needed to do with our lawn. When I told him the bushes by our house were Azaleas he said there was no way that was what they were because they cant grow like that in Dallas. He then went and looked at them closer and said, "Wow, I can't believe these are Azaleas! I don't know if it matters, but we don't have Encore Azaleas. Those weren't out when these were planted. Some of mine are 6 feet tall and some are the smaller 3-4 feet varieties, all in different shades of pink. My point is that if you really want Azaleas and you are willing to bring the right dirt in, they will do amazing! I kill everything I try to grow and mine still look great! Good luck with your decision!

hi, there are dwarf crepe murytles in seversl different colors they are on the web henry's garnet itea it is dwarf.there are many dwarf conifers.don't give up on azaleas. dj

Rhododendrons are easier to grow than evergreen azaleas in Zone 6. The small leaved rhododendrons like PJM are bulletproof. If you have good acidic soil, good drainage and mulch them, they will do very well. There are many other large leaf and small leaf rhododendrons that do well in Zone 6. Evergreen azaleas do well once they get established. It is the first 3 years that they tend to be the toughest to grow.