Answer: Unfortunately, the traditionally espaliered plants such as fruit trees, pyracantha and roses will not do very well in shade. Most shrubs also require a certain amount of sun to do well, and in less than optimum light will grow leggy and thin rather than dense as needed for a successful espalier.
Since you have a heavy clay soil, blueberries may be very difficult to grow; they require a soil with a high level of organic matter and a pH close to 5. They are also usually grown in full sun and grow slowly. You might check with your County Extension (tel. 292-5250) to see which varieties they suggest for your area. They can also help you with performing some basic soil tests and determining what soil amendments you might need to add in order to grow various plants.
You might wish to consider some of the vines such as the native Virginia Creeper or the naturalized, fall blooming "Sweet Autumn Clematis", both of which will tolerate a good bit of shade and could be directed to grow in patterns. Another possibility, although not native, would be the various evergreen euonymous species. These will grow as shrubs or, when a support is available, will also climb, thus allowing you to keep the planting narrow.
Good luck with your project!
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