Rooftop gardens take the enjoyment of plants to a new level. Cars rush by on the streets
below while gardeners on rooftops and terraces enjoy the unusual perspectives offered by the
setting. These gardens have a mood all their own. Because they are much smaller than the
average back yard, they challenge gardeners to think about what is really essential, and the
results can be unexpected and extremely striking.
Just like gardens on the ground, rooftop gardens are “an escape — an escape from everything
else that’s chaotic,” says Bill Jennings, a garden designer in Kansas City. A rooftop or
balcony garden demands a good design, he says. Pots and planters should be an appropriate size
(bigger is better), and they should be arranged to take full advantage of the space and look
attractive through the windows from inside. Jennings recommends simple containers. “If the
container itself is simple, you can do some exciting things with the plants,” he says.
Jennings lines pots with coco fiber, which keeps the roots cool and provides insulation in
the winter. He recommends soil-less potting soil mixes, which are lightweight and designed to
both drain well and retain moisture.
Plants in rooftop gardens are exposed to more extreme conditions than plants in the ground,
but many great garden plants will thrive if you choose carefully and take care of them. A
watering can or a hose may be all you need, but consider installing drip irrigation, especially
for large rooftop gardens. Here are some hard-working rooftop plants Jennings recommends:
— Trees: Choose smaller trees and little-leaf varieties, such as Amur maples, Japanese tree
lilac (Syringa reticulata), Japanese maples, staghorn sumac, and crabapples. Trees and
other tall plants may have to be tethered to railings to keep them from blowing over; bungee
cords will do the trick.
— Evergreens: Pines, junipers, and dwarf conifers of all kinds do well in these
— Shrubs: Boxwoods, cotoneaster, Japanese kerria, hydrangeas, barberry, and yew are very
—Roses: Roses of all kinds — including climbing roses — will thrive in pots in a rooftop
— Perennials: Try hostas, ferns, astilbe, daylilies, lavender, yarrow, artemisia, and
Russian sage. Smaller ornamental grasses add luxurious texture. Sedums and sempervivums are
also great choices.
— Annual flowers thrive in containers with other plants, or in pots on their own. Some good
choices are: zinnias, pentas, lantanas, marigolds, petunias, torenias, and impatiens. Annual
vines, like cypress vine and morning glory, will grow rapidly and bloom through the fall.
— Vegetables: Tomatoes, cucumbers, peppers, zucchini, broccoli, and lettuce and greens are
good candidates for pots. Herbs also thrive in containers. You could even grow strawberries and
raspberries in big troughs in a rooftop garden.