Answer: Hostas are usually not pruned. If they have become too large, you can dig and divide them - either in early spring or in the fall. I find it easiest to dig the entire plant up and then cut through the root mass with a sharp garden spade or shovel. Each division should have some roots and some foliage. Replant the divisions as soon as practical to keep the roots from drying out too much.
Boxwoods can take an annual shearing to keep them dense and full. If the plants have bare centers and you cut back to the bare stems, they will not grow new leaves except, perhaps, at the tips. I think I would simply shear off a few inches at the tips of the plants to encourage new growth and then plan to shear them back by a few inches each spring to promote even more new growth. Eventually they will look more lush and green, although the centers of the plants may remain bare of leaves.
Summer squash can be grown in a 1/2 barrel without problem. I think they'll look lovely as they cascade down the sides of the barrel.
Good luck with your landscape!
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