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What's Up Magazine

On Top of the World: Rooftop & Balcony Gardens

Aug 18, 2018 12:00AM ● By Brian Saucedo

By Janice F. Booth

Summer is in full glory, and beautiful gardens have been delighting our eyes with color and grace for months. But those of us who live in condominiums or apartments may be feeling a bit bereft, missing opportunities to dig around a bit in the soil, clip and trim, or relax in a comfy lawn chair watching our own plants flourish.

No need to pine if you’ve given up lawns for an apartment or condo. If you’ve got a bit of flat roof, you have a potential garden. If you have a balcony, you’ve got a garden space. “Some of our residents like to nip a few leaves,” says Edward Dunlap, general manager of the Grandview Condominiums at the Annapolis Towne Center. “For our rooftop community area, we’ve included a mixed-herbs garden where residents can grow their own kitchen herbs.” 

Rooftop gardens open an under-utilized area for private or community enjoyment. If you belong to a condominium association, there may be other residents who would share your happiness of an outdoor garden. Gain the approval of the condominium association and a budget, then you, and perhaps your committee, can begin the planning and installation of a rooftop garden.

First, the obvious: Engage an engineer to check the roof’s weight tolerance and prepare a plan for installation of plumbing and electrical. Then, secure the necessary permits; your engineer or a landscape specialist can help with that. Next, determine the prevailing winds, and whether other buildings will shadow parts of the garden—when and for how long each day? 

Now, the fun stuff: Since you’re using the roof, you may need railings and even privacy walls or screens as wind-breaks. Consider whether you want to use transparent and light materials for these structures, such as glass and Plexiglas for open vistas or wood and bamboo for privacy. 

Depending on the square footage, you may want to plan portions of the garden for entertaining and quiet relaxation. Once the usage is clear, the flooring can be chosen. In an article on rooftop garden design, balconygardenweb.com suggests keeping the floor simple and carefree. For example, painted concrete with easily-replaced indoor-outdoor area rugs. 

Furnishings will depend on two things; first, the roof’s prevailing winds and second, your usage plan. The furniture you choose could become dangerous projectiles flying off the roof in a storm. So, the furnishings must either be heavy and sturdy or light and easily stored in an appropriate receptacle when storms threaten, or winter arrives. There are many durable, attractive, comfortable choices from teak to wicker; just add comfy cushions and sun umbrellas.

Once you’ve settled on furnishing, where will you use lighting—strings of lights, decorative lanterns, spotlights? Be sure to plan for safety; perhaps, motion-activated lighting for stairs and entranceways. 

Now, let’s get to the real reason for all this planning—plants. There are two choices for planting, raised planter flowerbeds and pots. A combination gives you the most versatility. Raised beds are easier to plant and maintain; pots provide interesting choices of material, methods of clustering, and the ability to change a plants location as it grows. Raised beds are usually rectangular and can be built with convenient ledges for seating as one works among the plants or for casual guest seating. Pots can be chosen for height and volume, offering dramatic punctuation to the simpler beds of flowers. (Hint: Dramatic, tall pots don’t have to be filled with soil that weighs a ton. Fill the first third of the tall pot with packing peanuts. Then, add potting soil up to the correct depth for your plants. The peanuts will allow water and oxygen to flow down and around your plant’s root system. The pot will be lighter, and the plants will be happier.) 

Think of height, breadth, and color when you are choosing plants. If there’s an unattractive building next door, a raised bed filled with graceful and carefree decorative grasses may be the perfect camouflage. Does the neighbor’s bedroom window overlook your roof garden? A cluster of large pots of varying heights planted with a crape myrtle in one pot, bamboo in another, and a dramatic cluster of yucca in two more—there you have it, a lush, living privacy screen that will be attractive to your neighbor.

Be prepared to do a bit of replanting throughout the season on your roof. The winds and direct sunlight will take their toll. If you plant some annual beds they can be refreshed periodically; you won’t get frustrated with the tired-looking plant that was in full bloom in early June but looks quite withered by late July. Two plant families do well under these harsher conditions: succulents and herbs.

It’s fun to experiment with succulents and cacti; a rooftop is a perfect place for them. Unfortunately, they offer little variety in height, and the colors are muted, so don’t count on your succulents for drama—unless you can coax them to flower. A cactus in bloom is as breathtaking as any rose or dahlia.

Herbs are hardy and useful additions to your flowerbeds. You may have your favorites— marjoram, sage, oregano, and it’s wonderful while cooking to snip a few leaves or branches from your own herb garden.

And that brings me to a challenge for every garden, particularly if that garden is sunbaked and windblown­- irrigation. Unless you or your condo have budgeted for a gardener or the building manager offers to take on the task, how will you water your rooftop garden? While the weather is unpredictable, as we all know, you will probably need to plan on daily watering in midsummer. And, since getting away from such household chores was the motivation for many condo residents, who wants to volunteer to stay around to handle the daily watering of the rooftop garden?

Don’t panic or start tearing up your garden sketches quite yet! There are a few options. The easiest and most reliable irrigation solution is soaker hoses on timers. The hoses are installed along the surface of the flowerbeds and covered lightly with mulch. The timer is set for specific daily watering times—usually morning and evening. If you have an engineer or are smart with piping, you might collect rainwater for irrigating. And if there’s an air conditioner whirring away on the roof, catch the condensing water and run a hose into one of your flowerbeds. 

But as you may already be thinking, what about the potted plants? 

Flowerpots demand a bit more ingenuity when it comes to automatic watering. And, unfortunately, there are no solutions that would allow for weeks without gardener assistance on the watering. The two options that allow pots to be untended for two to three days are water wicks and soaker bottles. Water wicks can be devised from old-fashioned lamp wicks (available at camping stores) or from cotton roping (available at sewing supply stores.) The wick is strung from a pot or jar of water to the flowerpot. Be careful that the water source is higher than the flowerpot, so that the water will wick down into the plant. I would advise testing the set-up while you’re around to be sure the water source and wick work correctly. 

The soaker bottle is relatively foolproof, but it too should be tested before leaving your plants for days on end. The simplest soaker bottle is a recycled water bottle. Punch holes in the sides and bottom and discard the cap. Bury the bottle in the soil among the plant’s roots, leaving the bottle opening just above the soil level. Fill the bottle, and let it slowly drain out into the plant’s roots. If your pot does not have room to share with a water bottle, you can try this: Simply give your potted plant a deep soaking. Then, take a large, full water bottle and turn it upside-down into the plant’s soil about an inch or two. The bottle will slowly drain, watering the plants in the pot. (Be sure you’ve thoroughly watered the plant before adding the water bottle or the water will immediately drain into the pot, and you’ll still have days to go before the plant gets another soaking.) There are lovely, blown-glass watering receptacles too. They’re a bit harder to fill, but provide a more elegant solution than the old, plastic bottle. 

Just a reminder, no matter which methods you choose for irrigating your rooftop garden, be sure to fertilize your plants periodically. The potting soil gets pretty tired after a while and your plants will need occasional boosts. 

A quick glance around your once-barren rooftop will tell you what you’ve achieved. You have created an oasis, where you can watch the birds and bees, feel the summer breezes, and putter about in a bit of earth. Don’t tell those ground-based gardeners, but an added bonus to a rooftop garden—few insects or pests. The breezes will keep mosquitoes and flies away, and ticks can’t fly. Not to mention, no dogs peeing on your plants or kitties pooping in the flowerbeds. 

But wait, before I close, what about those of us who have no flat roof to transform? What if a narrow balcony is your only private access to the great outdoors? Fear not! You too can enjoy a tiny garden. A few flower pots, an over-the-railing flower box, a hanging pot or two—and there you are. Butterflies and hummingbirds will find your bit of Eden in no time. Use the same suggestions about watering and fertilizing. Be prepared for some attrition among your pots, and don’t feel too bad if you must replant now and again. 

I don’t think there is an area too small or too large that it can’t be improved by plants. Gardening on your balcony or your roof can be just as satisfying, and perhaps less frustrating and exhausting than maintaining a formal, land-based garden with all the work that entails.