You’ve moved to a new apartment with a balcony. An outdoor space brings nature into your living area, it can be home to bright flowers and screening trees, and might easily become your favorite place to read, snack, or chat. But like all spaces it must be made ready. So along with the new space you probably have a few questions: What can I plant on my balcony? What are the easiest plants to grow in containers?
Can you see your balcony from inside your apartment?. What direction does the balcony face? (If south, think vegetables, herbs, and bright flowers). North or west, plant flowers that thrive in shade (there are many!).
A balcony garden has definite and unmovable borders. (There is no other side to a balcony fence!) Most apartment balconies today are 8, 10, or 12 feet long and 4 or 5 feet wide, while some “tiny balconies” are only a few feet wide and long.
Tip: Add a horizontal container at the edge of your balcony to increase the sense of spaciousness ― its blooms will draw the eye to the farthest point. Herbs, berry bushes, and flowers work well in containers.
• Is your balcony part of a fire escape? If so, make sure to keep the exit clear.
• Is there is a waterproofing membrane on the floor? Be careful not to puncture it when fastening containers or furniture.
• What does your city’s fire code say about the amount of combustible material that can be placed in an area? When possible, choose materials that do not burn ―furniture and containers made of stone and metal, not wood.
• Is your balcony close to the exhaust vent from a stove or air conditioner? Does it overlook a traffic intersection? A plastic baffle is a big help to redirect poor-quality air.
• How much weight can your balcony bear? A balcony garden holds plants, containers filled with soil, gardening tools, and, perhaps furniture. Check with your super and/or building engineer before adding a heavy tree. You will not want to grow plants higher than 6 to 8 feet because taller plants need deeper pots to stop them toppling in the wind. The deeper the pot, the greater its weight on the balcony floor, and the soil, plant, and the water it consumes all contribute to its weight. The weakest point of any balcony is its middle, so keep heavy pots around the perimeter.
• Is your balcony stacked beneath other balconies? If so, the plants you place on it will not get direct sunlight and rainfall. And as the summer sun travels high in the sky, a shadow from the balcony above will shade yours below. If your balcony is in shadow much of the day, you can still enjoy ferns; houseplants, such as Christmas cactus; and vines like the Hoya and philodendron. Water plentifully.
Your balcony is the place to express your preferences for certain colors and plant shapes. Leafy trees, evergreens, summer flowering annuals, perennials, screening vines, even roses, can find a place on a balcony. Select just a few plants, particularly those that require little care. Expand your selection later when you see what plants thrive on your balcony ―a sun-loving geranium, or a lobelia in a shady spot, for example.
Tip: Mass your successes, rather than “spot” different kinds of plants. A simple plan is best. Plant several plants in a larger pot for color impact, rather than many small pots.
Plants for all seasons
If you can see your garden year-round from the inside of your apartment, plant an evergreen. These are green all year, and some thrive in small containers ― boxwood and small Norfolk pines withstand balcony wind.
Plants for sunny exposures
Plant pansies and petunias, geraniums, hollyhocks, daisies, daffodils, lilies, cosmos, and verbena to fill east or south-facing balcony gardens with color. You can raise these annuals from seed or purchase young plants from a garden center. Sun-loving vegetables include: tomatoes, peppers, and pole beans, which can be staked so they do not take up much room. They need six to eight hours of bright light.
Plants for shady exposures
Shady balconies are tranquil places that can be brightened with summer-flowering annuals like pink, white, and orange impatiens, fuchsias, larkspur, and torenia, the wishbone flower. Bleeding hearts in hanging pots are useful backdrops for a balcony garden. For perennials, flowers that bloom year after year, choose: periwinkle, lily of the valley, Jacob’s ladder, violets, and blue forget-me-nots. Vegetables that cope with shade: carrots, scallions, and cabbage.
Plants for the tiny balcony
A vine or an espalier tree can climb from a narrow trough flush with the wall. Suspend flowering plants in hanging baskets from an awning or roof.
A balcony garden faces more challenges from the elements than gardens planted on earth. Sunlight on your balcony raises the temperature in its small space and can play havoc with humidity too. Strong wind and sparse water from rainfall are other elements that you cannot control, but you can lessen their effects in your growing environment.
Temperature and Light
The sun is hotter on south-facing balconies. Lower the temperature on your balcony by spraying water on its floors and walls late afternoons, if possible.
North-facing balconies capture only two hours light a day, getting most from mid-March through the end of June, when the sun moves north in the sky and days get longer.
Tip: Add more light to a north-facing garden by adding mirrors and painting the walls a light color to increase the reflected light.
Wind courses around buildings, knocks over containers, and rips at a plant’s tender leaves. Is your balcony on the 3rd floor or the 40th? The higher the balcony, the stronger the wind. If your plants are wilting, they may be telling you that wind is causing stress. An open-textured screen, a plastic barrier, or a living hedge protects plants on an open balcony buffeted by wind. Check to see if your apartment restricts enclosures on a balcony. If so, permeable chicken wire covered by climbing vines offer protections.
Water: The Balcony Gardener’s Watchword
A balcony’s exposures to strong sun and wind demand that its plants be continually watered. Rainfall, which nurtures plants in the ground, evaporates quickly on the small soil surface of containers. Rain may not even find its way to a container’s soil because the plant’s leaf canopy often overhangs the surface beneath. Much-needed rainwater can flow directly onto to the balcony floor rather than into your pots. The balcony gardener must be the main supplier of life-giving water. While larger balcony gardens often have spigots or sprinkler systems, a beginning balcony gardener must work with simpler tools:
• The fastest way to water is to use an easily-coiled nylon hose attached to a kitchen faucet.
• Water the plants, floor, and walls of your balcony with a gentle spray that will not impact the balconies of your neighbors.
• Water by hand with a two-gallon watering can.
• City soot will find its way to your balcony garden, coating a plant’s leaves. Spray the upper and lower surfaces of a plant’s leaves to clean and nourish them.
• Cluster containers close to each other to combat evaporation and water deeply in the morning so that less water is lost to evaporation.
Containers and Soil
Think light. Plastic containers are lightest and easiest to move, and as the seasons change and light shifts, you will want to move your containers. The plastic pot, though, is not a complete answer. Winds can blow over a plastic pot and sun quickly dries out its soil. In winter’s cold, a plastic pot will not protect the roots of perennials, so it must be insulated with wrapping. A thick terracotta container may be the most stable and most protective for plants, as well as work-free for you. All pots must have drainage holes at the bottom.
Tip: For better temperature control and stability, place plastic pots inside terracotta containers.
For great drainage, place pots on gravel placed on the balcony floor or on a raised bed. Fill your containers with the soil that comes with the plants you buy. If you need more, add potting soil (organic), which is lighter than garden soil. Pebbles and bark chips are good toppings to stop the soil from drying.
After fall’s frosts, pull up the annual plants but leave the old roots to enrich the soil. Without the plants, the snow and rain will reach the soil and cleanse it for the new growing season to come.
Note that in accordance with NYC Local Law 11, owners of properties higher than six stories must have exterior walls and appurtenances, such as balconies, inspected every five (5) years. Although this may not have any bearing on your balcony garden, if you are renting an apartment in NYC it may be helpful to speak with your building's manager or owner about your balcony gardening ambitions before starting a large project.