1. How much sun does your balcony get?
If you get more than 6 hours of sun per day, choose plants that like full sun and can tolerate hot, dry conditions. If your balcony is too hot and sunny, consider creating some shade to reduce how often you have to water and increase the range of plants you can grow. Areas that get between 3 and 6 hours of sunlight are considered partial shade situations - annuals such as Lobelia and Nicotiana and perennials like Bellflowers (Campanula spp.) and Columbines (Aquilegia spp.) will all tolerate less than 6 hours of sunlight per day. Under 3 hours of sunlight per day is considered full shade - use shade-tolerant plants, like Hostas, Astilbes, Begonias and Impatiens, that flourish in low light.
2. What direction does your balcony face?
South and west exposures will get more intense light and heat. Choose drought-tolerant plants to reduce watering and hot colours to combat glare. North exposures are much darker and cooler, often in full shade for most of the day. Use white and pale coloured flowers to beat the gloom. Eastern exposures that warm up in the morning sun and are shaded in the afternoon are perfect for pastel tones and plants that like moist soil.
3. When are you out on your balcony?
Most flowers bloom all day long but some, like Morning Glories, California Poppies and many Daylilies, bloom only in the morning, so make sure you'll be around to see them! If you work during the day and really only enjoy your balcony in the evening, white flowered plants and those with silver foliage will really stand out in the dark. There are also many night-blooming flowers available, most of which are very fragrant: Evening-Scented Stock (Matthiola incana), Angel's Trumpet (Datura innoxia), Night Phlox (Phlox 'Midnight Candy'), Flowering Tobacco (Nicoltiana alata), Four O'Clocks (Mirabilis jalapa) and nocturnal varieties of Daylilies (Hemerocallis 'Moon Frolic', 'Punk' and 'Hyperion'). Good edible plants for night-time viewing include White Pumpkins ('Boo'), White Eggplants ('Gretel' and 'Alba'), Silver-leaved Thyme and Variegated Mints.
4. How much time can you devote to your garden?
In a container garden, maintenance and weeding are usually minimal but in hot weather your plants will need daily watering. And remember that the smaller the container, the quicker it will dry out. If you get fed up carrying heavy watering cans out to the balcony, try hooking up a special indoor hose that attaches to your kitchen tap. Self-watering containers will keep plants moist for a couple of days but plan on hiring a plant-sitter to water them if you're away for more than a weekend.
5. Do you need to create shade?
Umbrellas, awnings, sunshades and shade nets can all be used to create shade on your balcony or deck. Make sure umbrellas and shades are secure so the wind doesn't carry them away. Vines on pergolas can also be used to create shade, but make sure they're fast-growing types. Once all danger of frost has passed, taller house plants such as palms and dracaenas can be brought outdoors (gradually, over a period of days, so they don't get sunburned) to provide shade over seating areas. Tree-form potted plants like Hibiscus standards can provide shade to smaller plants and are available at most grocery garden centers throughout the summer.
6. Do you need wind barriers?
The higher you are, the colder and windier it will be. Not only can wind make it uncomfortable to sit out on your balcony, it can also dry out plants, break stems and scatter flowers. Consider closing in open railings with wood, vinyl or clear acrylic paneling, if allowed. Weather resistant fabrics such as canvas work well and old vinyl tarps can be used if you and your landlord are not fussy about colour. Make sure all wind barriers are securely fastened, to prevent wind gusts from tearing them off. Tall, narrow conifers or evergreens in containers are also good at screening out wind but must be treated as annuals in our area unless planted in well-insulated planters and wrapped in burlap for the winter.
7. Do you need to create privacy?
Bamboo panels, old bamboo blinds, cedar lattice or trellises holding fast-growing vines will all screen your balcony and make it seem more private. Tall plants in large containers can also form an effective privacy barrier. A series of hanging baskets can screen out harsh sunlight or upstairs neighbours. Even window boxes provide some privacy that you can peep out over. Recycled items make great trellises - try old security caging, chain-link fence panels, old gates and wrought iron fencing, even discarded clothes racks - don't limit yourself to the garden center or hardware store.
8. Does the public see it?
If you're concerned about the curb appeal of your balcony, try to follow the style and colour of your building as much as possible. Brick structures look best against warm tones like yellow, orange and red while concrete buildings often suit cooler colour combinations. Furniture and structures like trellises should copy or complement existing building materials. Containers in similar styles or colours present a more unified look. Mass plantings of one type of flower in a bold colour can make a simple but elegant statement if your balcony faces streetside. Or mimic the plants already used around your building exterior to create a seamless effect. If you have a container at your entrance that needs to make a statement, use a decorative pot and a mixed planting, perhaps with a showy specimen plant.
9. Do you entertain on your deck or balcony?
Make sure to provide comfortable seating so your balcony can easily become another room when entertaining. Shade is essential if you have guests during the day. Dining areas should be sheltered from the elements and as private as possible. Small BBQs are permissible in many buildings. Consider night lighting, strings of party lights, or small solar lights on sticks
10. Do You Know the Rules?
Be familiar with the rules and regulations in your building - some landlords & condo associations will not let you put up anything on exterior walls, others will limit what can be hung off the balcony. Also be aware of the total weight that your balcony can support. A 36"x36"/90x90cm planter full of wet potting soil can weigh more than 150 pounds/70 kilos. Consult with an architect if you're thinking of building large planter boxes, to make sure your balcony can support the load.
11. Got Art?
Consider adding some art to your balcony garden - metal, ceramic and wooden items will stand up best outdoors. Pieces can be free-standing or affixed to exterior walls or railings. Use artwork as a focal point to attract the eye to the best views of your garden. Consider the size of any sculptures, statues and fountains you may want to use in relation to the size of your space -- don't overwhelm a small balcony with a giant Buddha. Too many smaller pieces can also be distracting - try grouping similar items together in one spot for best effect. Choose pieces that complement your containers and your balcony furniture, whether modern, classical or offbeat. In the Ottawa area, remember to bring all artwork inside for the winter. This includes terracotta pots, which will not withstand frost without cracking.
Datura inoxia (Angel's Trumpet)
Mentha piperata variegata (Variegated Peppermint)
Hosta 'Blue Wedgewood'
Solanum melangena 'Gretel' (White eggplant)