10 Secrets for Growing an Urban Balcony Garden

Raised in South Africa by a mother who is a ferociously good gardener, Marie Viljoen had one non-negotiable requirement when she went apartment hunting in Brooklyn. “I took this tiny, tiny apartment only because it had a terrace on the top floor of a brownstone, where it was open to the sky,” she says. “I knew I could have a garden.”

A small terrace, to be sure–the size of a bathroom, say, or a walk-in closet. But Viljoen, taking advantage of the good light, a wide ledge for pots, and enough floor space for a table and two chairs, has transformed it into a lush garden where she dines outdoors and grows much of her food.

Viljoen’s garden, inspiration for the 66 Square Feet blog where she chronicles her gardening and cooking adventures in New York City, also has spawned a book; next month, she will publish the cookbook 66 Square Feet: A Delicious Life (you can pre-order it for $19.95 from Amazon).

Here are her top tips for creating an edible urban garden:

Photographs by Marie Viljoen.

 Marie Viljoen’s Top 10 Tips for Growing an Urban Balcony Garden:

1. Use a high-quality organic potting soil and augment it with compost.
2. Layer plants that bloom at different times on top of one another in containers–and fertilize once a month.
3. If your terrace is sturdy enough to support the weight, cover the floor with filter fabric and a shallow layer of gravel so plants can self-sow and naturalize.
4. Study how sunlight moves across the space over the course of a day and cluster your containers–sun lovers vs. woodland plants–in areas where they will thrive.
5. Clustering pots makes it easier to water plants efficiently. Most containers will dry out and need water every day; during a heat wave, water twice a day.
6. Make your peace with pests. If squrrels dig up a pot in the course of burying an acorn, be happy you’ve created a wildlife habitat in the city.
7. Plant a pollinators’ favorites to attract bees and butterflies. “It’s lovely to see them up here,” says Viljoen.
8. Herbs are the easiest edibles to grow in containers.
9. Some fruits also are surprisingly easy to grow in containers too: blueberries, for instance, and currants. “A lot of people are surprised by the success of my fig tree,” says Viljoen.
10. Vines and fast-growing climbers are good for a small space because they will lend vertical interest quickly.

Above: To attract pollinators, Viljoen grows agastache, hyssop, Japanese anemome, and Bulbine frutescens, a native of South Africa that has orange flowers.

Above: “Everything I grow is in a pot, with the exception of the naturalized herbs and violets that are coming up in the gravel I put down to cover the ugly, pressure-treated deck floor,” says Viljoen.

Viljoen covered the floor with filter fabric and a 1.5-inch deep layer of gravel. “Choose plants with shallow root systems and make sure they have access to water,” she says.

A 150-square-foot roll of Greenscapes Premium Landscape Fabric is $13.78 from Lowe’s.

Above: Violets thrive–and have naturalized–on the balcony floor. Also growing in the gravel are mint and creeping jenny, on which Viljoen’s cat loves to sleep.

Viljoen feeds all her plants–including those growing in the gravel–monthly with a “fishy emulsion” of Neptune Fish/Seaweed Blend organic fertilizer; a 5-gallon pail is $143 from Nature’s Harvest.

Above: “Everyone asks about varmints, but I’ve never seen a pigeon in the garden. I grow strawberries and figs, but they’ve never been attacked by birds,” says Viljoen.

Above: “Some fruits are easier to grow in pots than in the ground,” says Viljoen. “With blueberries, it’s easier to adjust the ph level in a contained environment. My ph modifier is fresh coffee.”

Viljoen layers plantings in pots so something is always blooming throughout the growing season. The deepest layer is summer bulbs. At mid-level are perennials. In the top: annuals.

One of Viljoen’s favorite late-season bloomers is Plectranthus ‘Mona Lavender,’ ($5.98 apiece from Lowe’s), a South African native with purple flowers.

“It’s lovely to have something blooming in October,” she says.

For more ideas for creating a small-space urban garden, see Required Reading: The Edible Balcony.