Starlight I grow 3 hydrangeas at varying distances from the maple: 1 arborescens (6 feet), 2 macrophylla,Twist n' shout 9 feet, Endless summer 13 feet. The tree is in my neighbour's front yard and is seperated by their pathway from our yard, which is slightly higher 2-4 inches. The maple's canopy starts way up. But the roots are all over the place, and unless we have major showers no rain can past that canopy. H. arborescens is really big and continues to sucker all over the place. It is rarely watered in the summer. but it thrives. However, both macrophyllas are water hogs. Mulched, mulch-less they drooped especially the 1st 3 years. Remember my soil is 100% sand. In the first 3 years, I had to water it regularly. Sometimes every day (especially in heat waves) or every 2nd day. I just put the hose in it's crown and let them drink. However, since this year, 5th year, I have to water it much less. Maybe once a week if we don't have any showers. The plants are healthy and flower. Mine receive dappled light and some 1 or 2 morning sun. And the one that receives the afternoon sun hates it. In retrospect, if I had amended my sandy soil properly with organic matter, I might have a had a better result. SG the worse year with the hydrangea was a freaky one when the snow melted in mid March and then we had a freakish cold weather -4 wind chills etc. That killed all the top buds. Last year, during the polar vortex I couldn't cover the top buds of Twish and shout. Nothing happened to it. From my experience it isn't the winter but a roller coaster spring that can kill the confused buds on the old growth.

I have frequently attached a 4' trellis to the top of a fence as a line of sight sight screen. With a 4x8 you can increase the fence by 3 to 3.5' taller, and very economically cover 8'. A series of these could do your whole back fence. I attach them by predrilling to not crack trellis wood and using deck screws and electric screwdriver. A climbing hydrangea is slow growing at first. It gets quite woody, very large, and very heavy, like a Wisteria it might break a lighter to mid duty trellis. Honeysuckle 'Scentsation' or a smaller trumpet vine such as 'Indian Summer' may work better and survive in zone 5b (tbey are rated to 4). They drop their leaves, but might block quite well, except in winter. If this was my fence I'd pair Honeysuckle 'Scentsation' with Clematis 'Jackmanii' both have a long season and repeat blooming. That also gives you fragrance and hummingbird draw. The honeysuckle also has nice red berries late in the season for visual impact and the other birds. Both grow fast and together you should get enough vine growth to be a decent Winter block. Here's an internet photo of the in bloom appearance. The light colored honeysuckle really shows up in a twlight garden. And it does get woody too for that forest cottage look. I'm guessing this honeysuckle would cover about 20' linear. And one Clematis half of that? I've actually started this pair on my gazebo entrance.

Be aware that most establishments, including online ones, may have a limited supply of hydrangeas at this time of the year. As soon as they stock up, you should see more variety. The locals will get stock up depending of weather in your area; usually May for me. The online ones sometimes tend to advertise by email and can sometimes notify if/when a specific variety comes in. You have to obviously give them your email address somehow. Hydrangeas Plus has a way to give them your email for seasonal emails in their website.

Might get better results asking here instead: http://forums.gardenweb.com/forums/hydra