Answer: usually, plants are inserted into a rock wall while it is being built and then spread naturally throughout the area if they are well suited to it. If your wall is already built you may want to use trailing plants at the top and let them hang down. In front of the wall you could plant almost anything you like as long as it is suited to the growing conditions in general. For the shady area you could consider Vinca minor plus named varieties of Ajuga and named varieties of English ivy such as those with variegation or specially shaped leaves. The ivy will climb or trail, the vinca and bugle will trail somewhat. Lady's mantle may seed itself into cracks below if you plant it at the top. Corydalis lutea may also do that for you in shade to part shade. For the center partially sunny area you could consider various sorts of Euonymous fortunei which will climb or trail. For the sunny area you could plant any number of small sedums, creeping thymes, creeping dianthus, arabis, alyssum saxatile and creeping phlox as well as trailing junipers and possibly alpine strawberries. Rockspray cotoneaster is also very pretty trailing over a wall. As you work with the area and experiment a bit, you will see what works best in each area and can then add more of that. Unfortunately deer may develop a taste for nearly any plant, so you may need to use the repellents and/or a fence. I am not sure what bears like to eat, but since these plants do not fruit (except for small berries on the cotoneaster) I would not expect them to be attracted to the planting.
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