Suitable vine for balcony

(Question)

I want to grow fast-growing vine to cover my west facing balcony wall. Which type of vine is best without being overly invasive? I have tried moon flower with a supporting structure. while the moon flower took hold but it was never as robust as I’d like it and only partially cover the trellis. Is trumpet vine a good candidate in my circumstance?

(Answer)

Thank you for asking about a fast-growing vine for a west facing balcony wall. There are a number of factors to consider that will help you narrow down your choices:

  • Consult with your building for legal, safety, and weight considerations. Plants, pots, and damp soil are heavy, and you want to make sure your balcony can support the weight.
  • Growing plants in containers on an exposed site like a balcony means your plants will need a bit more TLC to stay healthy; you will need to water and fertilize more often and offer more protection from the wind and other elements.
  • Vines can be annual or perennial. Annuals must be replanted every year, whereas perennials can be overwintered and will come back year after year.  Generally speaking, annuals grow more quickly and flower more profusely than perennials.
  • Hardiness is an important consideration if you are considering a perennial. While downtown Toronto is Zone 6, your balcony is more likely to be Zone 4 due to height and exposure. You should choose a vine that is hardy to Zone 3 or 4 if you wish to overwinter it. Vines that are hardy to Zones 5 and above should be treated as annuals in Toronto.
  • Sunlight is also an important consideration.  You mentioned that your balcony wall is west facing which suggests that it is quite sunny. However, it may be that overhanging balconies or nearby buildings may limit the actual amount of light that your vine will receive. Six or more hours of sun is considered full sun and 3 to 6 hours considered part sun. Be sure to check the light requirements of whatever vine you end up choosing.
  • And finally, vines need a support structure. You mention a trellis in your question but the trellis is not visible in your photo. Whatever support structure you chose, it must be sturdy enough to support the weight of the vine when it is fully grown.

You mentioned two vines specifically:  Moonflower (Ipomoea alba) which you tried but were not completely satisfied with the result; and Trumpet Vine (Campsis radicans) which you are considering.

Moonflower is a perennial vine in Zones 10-11 that can be grown as an annual in Toronto.  It is adaptable in terms of sunlight requirements, but more sun leads to more abundant flowering, and it requires regular watering. Moonflower is a twining vine and requires a trellis or similar support structure to climb.  You mentioned that you were not happy with the fullness of your Moonflower vine. If you wished to try it again, pinching back the topmost shoots should encourage more robust growth lower down, Training some of the branches by spreading them out and tying them in place with soft ties would help the vine cover more of the trellis.

Trumpet Vine is a vigorous perennial vine that is hardy to Zone 4.  Like Moonflower, Trumpet Vine flowers most abundantly in full sun and requires regular watering. It is a vigorous vine that requires a robust support structure to carry its weight and may grow out of control rather quickly. For these reasons, it is probably not the best vine for your circumstances.

Other vines to consider include:

Annuals

  • Black-eyed Susan vine (Thunbergia alata)
  • Morning Glory (Ipomoea tricolor)
  • Passionflower (Passiflora sp.)

Perennials

  • Kiwi (Actinidia kolomikta)
  • Clematis (Clematis sp.)

For more information on these and other options, the websites listed below may be helpful. Just a word of caution,however, some of the vines mentioned may be more vigorous than would be suitable for your balcony, and potentially invasive.