You haven’t lived until you’ve tried to dig in soil which has been covered with a thick layer of asphalt for at least 20 years. “Compacted” doesn’t begin to describe it. I rented a gas-powered post hole digger to make openings for the edging plants—190 yews and 320 boxwoods.
I purchased the upright yews first. To reduce their cost, I forfeited the warranty the garden center normally offers. Keep this in mind if you ever need to buy vast quantities of a single shrub, as it will often entitle you to a 10% discount.
Yews are extremely slow-growing evergreens, and thus even tiny, young plants (which I bought) can be very expensive.