Balcony flowering shrubs and evergreens

(Question)

Hello,

I live at Danforth and Victoria Park in a condo on the 12 floor. I have a very large L shaped balcony with north west exposure so lots of sunlight. The railings are glass so again lots of light.

I want to plant flowering perrenial shrubs that have a chance of wintering on the balcony. Also evergreens or other small trees such as service berry.

I have heard that Hydrangea can survive but not sure that is so. Would love to plant Lavendar or rosemary as well.

Thank you so much for your advice.

(Answer)

Thanks for contacting Toronto Master Gardeners for advice on planning your balcony garden.

Before you start

Determine the size of the space you have to work with, the lighting conditions and how much heat.

Check your building regulations. Find out if planters or trellises can be attached to walls or railings, and any balcony/ terrace weight restrictions.

Check the size of the building elevator to ensure the plants you choose will fit inside.

Decide how much time you want to spend caring for your garden and choose plants accordingly.

Containers/Planters

Wet soil is heavy, so factor weight restrictions into your choice of planter. Plastic or fibreglass containers are lighter than clay, concrete or metal. Your containers will need to be sturdy and secure enough to withstand the wind and elements. All containers should have drainage holes.

If you would like the plants to overwinter on the balcony, the containers will need to be large and insulated.

Watering

Consider how you will water your plants. Ensure your garden design allows excess water to drain where it should go, not onto your neighbors’ balcony directly below.

On balconies, the soil dries out faster due to high winds and the fact that plants are in containers. The overhang from the floor above also reduces the amount of rain your containers will receive. So be prepared to water your plants frequently.

Creating a windbreak using a trellis or screen or shrubs will help shield plants from the wind.

Plant Selection Tips

The plant hardiness zone for perennial plants declines the higher up in a building a unit is located. As a rule of thumb, those gardening above ground level in Toronto (zone 6a), should choose plants hardy to zone 4.

Larger and thinner plant leaves e.g. sweet potato, are more susceptible to wind damage. Smaller and thicker leaves retain more moisture e.g., hens & chicks.

When planting on a NW location, choose plants that thrive in a part-shade, drought-tolerant situation.

Plant Suggestions

Be sure to check the plant label to confirm the hardiness zone as the zone can vary by the cultivar of a particular species.

Perennial shrubs/small trees

Hydrangea typically like moist soil, so is not the best choice for a balcony.

  • Purple sand cherry e.g. Darkstar® purple leaf sand cherry
  • Burning bush, e.g. Fire ball® burning bush
  • Lilac, e.g. Dwarf korean lilac (tree form)
  • Service berry, typically grows 15 to 20 feet, cumulus serviceberry (amelanchier laevis ‘cumulus’) is a smaller more compact cultivar which grows to 10 feet.

Broadleaf Evergreens

  • Boxwood e.g. Green Gem, Green Mountain
  • Cotoneaster, e.g. Coral Beauty, Cranberry
  • Euonymus e.g. Dwarf Burning Bush
  • Yucca, e.g. Colour Guard, Ivory Tower

Evergreens

  • Juniper, most carpet juniper cultivars
  • Lemon Thread Falsecypress, Chamaecyparis pisifera ‘Lemon Thread’
  • Mint Julep Juniper (pom pom) Juniperus chinensis ‘Mint Julep (pom pom)’
  • Gold Cone Juniper Juniperus communis ‘Gold Cone’
  • Dwarf Alberta spruce

Herbs

Herbs such as parsley, basil, rosemary, sage, oregano, thyme, lavender and chives will grow well in containers.

Other ideas

You may want to also consider growing some succulents such as Sedum because they are well suited to the dry, windy conditions of balconies.

Grasses such as Karl Foerster Reed Grass and Hakone grass can also provide interesting accents and should do well in the balcony environment.

And don’t forget pollinator plants. Using plants of varying heights, including annuals, wildflowers, flowering vines and potted shrubs and trees is most effective. Climbers could include nasturtiums or morning glory which you can grow from seed.

Toronto Master Gardeners has a Garden Guide on Pollinator Gardening with a good section on attracting pollinators to your balcony. You can find it at https://www.torontomastergardeners.ca/gardeningguides/pollinator-garden-a-toronto-master-gardeners-guide/

Here is some additional information on balcony gardening: https://www.sheridannurseries.com/garden_tips/container_gardening/hardy_plants_in_year_round_containers

http://www.torontomastergardeners.ca/askagardener/balcony-gardening-2/

Good luck with your balcony garden.