i can think of no TREE ... and that is the key word.. that blooms more than once during a season ....

some SHRUBS might reflush .... but i would bet against trees ...

of course i cant do the tropicals that you might be able to get away with in your z9 ..... so who knows ...

the whole point of collecting plants.. is to extend the flower season .. over a range of plants that bloom sequentially ... and that is the only way i know.. to make a year round show ...

we could only wish that there were simply one to fulfill your dreams ...

ken

as Ken indicated there are no temperate trees that bloom all year. you might consider chilopsis linearis/desert willow which has pinkish flowers in summer and early fall as well as its hybrid with catalpa---x chitalpa "pink dawn". silk tree mimosa albizia julibrissim also has pink flowers over a long period but they dont particularly look like cherry blossoms except from a (great) distance. chorisia/ceiba and tabebuia have pink flowers with a long season but they are 9b/10 trees that need a reliably subtropical climate to grow and flower.

Yeah, emmenopterys henryi pink form. link here: http://forums2.gardenweb.com/forums/load/trees/msg0122442415589.html