I think I said it wouldn’t happen, not that it couldn’t. I believe that I hedged, thinking it wasn’t impossible, just unlikely that the ‘Black and Blue’ salvia (Salvia guaranitica ‘Black and Blue’, below) would find its way out from under the wide spreading paperbush (Edgeworthia chrysanthus).
When I planted the salvia several years ago there was plenty of space between the paperbush and a yellow fernspray cypress (Chamaecyparis obtusa ‘Fernspray Gold’). I had no concern that either would grow too wide because the salvia is very marginally cold hardy in this area, and I didn’t consider for a moment that it would survive. But, winters are not what they once were, and the next spring, there it was. Then, it survived another winter, and another, and a plant with a well established roots system is further strengthened, so it began to seem that it was here for good.
Until the paperbush continued to spread, far past the size listed by references and wider than the space allotted for it. A year ago the salvia barely managed, but by mid spring this year the shrub had grown another foot wider, and I peaked under its canopy, wondering if the salvia was still there. It was, but even by early summer it had so far to grow to reach the edge of the paperbush’s dense foliage, and without sunlight it seemed a nearly impossible task.
A seedling of ‘Tardiva’ hydrangea (Hydrangea paniculata ‘Tardiva’) sprouted from beneath the paperbush in July, and at first glance with somewhat similar foliage I thought the salvia had made it. But no, the salvia was still too far from the large shrub’s edge to believe it could reach the sunlight, and since it was in too difficult a spot to reach to transplant, the reasonable assumption was that this would be the salvia’s doom.
But today, here it is. After a few recent soaking rains it gathered enough energy to make a final push, set bud, and burst into flower. Now, I feel guilty for not having moved the salvia a few years earlier, and wonder if I can figure a way to move it in the spring before the paperbush leafs out. It seems the least that I can do for such a resilient plant.
Ramblin' through Dave's Garden 
Why not prune the paperbush back? Over the years I noticed I had a tendency to not prune unless very necessary. I often had an argument with myself over pruning. Finally, I concluded that this is MY garden, and I control what grows and how it grows, so now I thin and prune with much less guilt, and my plants do less fighting with one another for space.
I don’t do much pruning because it can be challenging to cut a plant and still retain its natural appearance. I’ve carved out a hole in this paperbush for a large, established hosta, but it requires pruning a time or two each year to keep it from being covered over. Also, a shrub that is pruned will often grow more vigorously, and fill in the area that has been pruned very quickly, so pruning leads to more pruning. I figure that if I planted something too close so that it requires pruning, I must suffer the consequences and either transplant the plants that are being overwhelmed, or lose them.