The Outsider: Beauty and Bounty in Park Slope


    WELCOME to The Outsider, Brownstoner’s weekly garden column, written and produced by Cara Greenberg. Find it here every Sunday at 8AM.


    ATOP a block-through garage, next to a one-family townhouse, 1,500 square feet of horticultural wonders lurk. Once a barren rooftop, the space now provides its owners with areas to rest, sunbathe, dine, and entertain — as well as grow both edible and ornamental plants, including many which are both.

    Brooklyn-based garden designer Cynthia Gillis conceived a ‘zig-zag’ plan based primarily on triangular shapes. “It makes the spaces more interesting than having a rectangle, and gave us a way to have a longer path, rather than a straight line,” she says. Raised beds with retaining walls of stacked bluestone are connected by paths made of leftover scraps of ipe wood. Underneath the growing areas are three layers: ordinary roofing material, a root barrier layer, and a water-retention layer (a plastic grid that holds water and allows it to be slowly absorbed into the soil).

    The separate triangles have different kinds of soil for different types of plant material: acid soil for blueberries, lingonberries, heathers, and pines; rich, deep compost in a sunny area outside the kitchen for perennial herbs like rosemary and sage, fragrant lavender, and a Concord grape on an arbor. There are creeping raspberries trailing over stone walls, mint and strawberries used as groundcover, and other edibles mixing freely with flowers, ornamental grasses, and evergreen shrubs.

    Find out more after the jump.

    The roof is accessed at one end of the kitchen through the kitchen door. Three steps lead up to the rest of the planting area. The roof structure was reinforced with steel before soil was brought in. “If you’re doing an ornamental green roof, you use lightweight soil,” Gillis explains, “but to grow crops you need actual compost, which is heavier.” There’s a tool shed down at one end of the garden.


    An unheated greenhouse at the kitchen end of the garden is used to start vegetables in winter and protect tender plants.


    Herbs in early summer, and grape vines starting their climb up the arbor at the kitchen end of the garden.


    Evergreens, blueberries, and other acid-loving plants thrive in a bed prepared with 4.5 pH soil.


    Among the ornamentals: pink muhry grass and cosmos, top, as well as hydrangeas, irises, day lilies, and Mexican feather grass.

    Photos: Cynthia Gillis 

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