"Endless Summer" hasn't been a great performer for me, some of due to just bad luck. I didn't realize that it prefers a little more sun than some of the other hydrangeas - one has to be careful here in CA, a lot of "full sun" plants will burn! I only could find two for sale, and unfortunately one croaked when we were gone on a trip and an unusual heat wave dried out the garden bed it was in.
Still, this one has survived, and done pretty well. With it is a Princess variety white dwarf alstroemeria. I really like this alstroemeria, but unlike a lot of plants, when it says dwarf, it MEANS dwarf. A flower stem is only 8-10" tall. It grows in a neat rounded clump, getting slowly bigger over time, and has beautiful white-edged variegated leaves.
just now seeing your post...so pretty! Both hydrangeas and alstroemerias are personal favorites. I've only tried to grow alstroemerias once though and I didn't have much luck. I've bought them many times for cut flower arrangements and really like the fact that they last so long. It must be nice to grow your own.