In the fourth of a series (here are parts one, two and three), Genevieve Brennan takes a glimpse into the Lower Haight’s hidden backyard oases. (Oasi? Oasises?)

Only a fence separates Mark Allen Ryan's backyard on Potomac Street from Duboce Park. Why work to cultivate a garden when you have an iconic stretch of lawn a few steps away? To have a quiet retreat, Ryan says. (Also: Duboce Park is full of dog poo.) The possibility of runoff from the park is also the reason that Ryan gave up hope of an herb garden and went with ornamental plants instead for his lush, compact yard. And ornamental they are: jasmine, bromeliads, a small delicate weeping willow, and bushes of daisies ring the yard. A Buddha statue sits tucked under an overhanging fuschia bush, and moss-covered stones form the border separating the garden from the lawn. A table and chairs are arranged right in the center. "That's the New England in me," the Connecticut-raised Ryan says. "Everything should be neat and manicured." Not that Ryan was afraid to get his hands dirty to get his garden started. Two years ago, he decided to revamp the yard backing up on his rental apartment. "It's called the garden apartment, so why not have a garden?" he says. At the time, the space was mostly dirt, with an aloe plant in the center. He moved the aloe plant to the fence, found bricks under the dirt, and used them to create the edged beds. They serve to contain the ivy, baby's tears and succulents that grow alongside the larger plants. Next, in went the lawn. Even more impressive? Ryan did it all without tools. "They were locked in the basement and I couldn't get in, so I turned the soil by hand and foot." The space has come a long way since then. Ryan now has a push lawnmower he uses for the patch of grass, the San Francisco version of the suburban dream. He chose what to put in based on what he remembers growing up with in New England. Ryan is delighted by one key difference: "Here we don't have a dead time." Indeed, there's more life in the yard than even Ryan would wish for. A coi pond sits empty in a corner of the space, its contents the victims of the neighborhood's aggressive raccoons. "They ate the coi and stole the filter pads from the water feature," Ryan says, conjuring up an image of a raccoon fluffing up the mesh filters before bedding down after a long night of knocking over neighborhood garbage cans and eating exotic fish. Unable to defend the yard from the raccoons was Klaus, Ryan's black and white cat. "Klaus likes to think of himself as an outdoor cat," Ryan says, "But he has no teeth." Klaus does keep an eye on the birds that flock to the standing fountain in the yard. Also present are hummingbirds, frogs, and a hawk that perches nearby. Recently Ryan saw a raven eating a sparrow, "Just gobbling down feathers." A little bit of Wild Kingdom in the Lower Haight. Not too wild, though; Ryan says his favorite thing about the yard is its livability. He eats breakfast and lunch there and has garden parties, though he minimizes the time he spends there at night in deference to the neighbors. Surveying the lush space while smoking an old-fashioned pipe, Ryan nodded. "I'm starting to learn the rhythms of the yard, I think."