Maybe grow as a tub plant put under cover during cold weather.

So far Agapanthus 'Storm Cloud' has been a toughy for me. I made the mistake of planting it behind blue oat grass. The blooms were wimpy. But it survives. I'm moving it to front of the border because I read they like sun beating down at their base.

Thanks for the advice! I've been doing some more looking on the web and apparently Monrovia has developed Agapanthus Midknight Blue that is hardy zone 6. I will try to track it down this spring and give it a try. I have a hot, dry spot in the front yard for it. It is winter that worries me...

There a number of cold hardy strains of Agapanthus available - the Headbourne Hybrids have been around for years and are listed to zone 6. Also a variety called 'Cold Hardy White', offered through High Country Gardens. And Xera Plants (located in Oregon) grows a variety of agapanthus they list to 0F. They are wholesale only but sell to a several Seattle area nurseries. 'Peter Pan' and 'White Profusion' are relatively common and are tough little dwarf plants that perform reliably in the PNW. I have a container planting of 'White Profusion' that I've grown for years and virtually ignore - it disappears totally over winter and then blooms like a maniac for several weeks in midsummer.

Container growing may be a good option. IME, these appreciate being root bound, the soil heats up decently in summer to produce reliable blooming and you can move them easily into winter shelter if necessary. One of the primary advantages of growing them in this manner is the ability to control drainage. I think most are lost over winter in our climate by overly wet, cold soils.

Avoid the species africanus - these are the most common evergreen forms seen inSoCal and tend to be the least hardy for northern gardeners. Most of the more hardy forms will be some type of hybrids or selections of campanulatus and are all totally herbaceous.