On our 10 acres this summer, I'm taking care of all the maintenance myself with one main helper. It's a full-time job, actually. (In the spring we have three helpers because cutting down the ornamental grasses, cleaning-up from the winter, and moving or dividing plants is just too much to do ourselves.)
I have a couple of exceptions to the D-I-Y regime: one is pruning big trees, which a professional tree service does for us, and the other is pruning the boxwood hedge around my four-square garden.
The master at that job is Bob May, a former gardener at Royal Botanical Gardens, who now runs his own business, which he calls the "Plant Sculptor". He's in such demand that although I called him in early June, he and his crew weren't able to get here until yesterday. He's so busy he can't take on any new clients so I'm glad I got in on the ground floor several years ago.