Answer:
While the gardener would probably appreciate the help, that is not the way into the Mews mansion. You can use the shears to make some rough cuts, much to the chagrin of the hedge owner. Fortunately, it grows back very quickly.
Once you find the $5 bill in the tree at the right, get a sports drink from the store for the thirsty gardener. Take his shears and go far left, to Cliff Park, where you can cut loose a hot air balloonist. He will toss you some nylon rope, which is what you need to go kite-surfing with a big kite from Kitty's Kites. Get the kite and go back to Cliff Park to use it.