Vines for shady courtyard?

(Question)

Hello Master Gardener!

We are hoping you can help us to choose vines for a shade garden. It is bright there all day, but only has direct sun for a short time each day on the north wall. The garden-to-be is a small space between buildings in downtown Toronto: it is 8 feet wide by 40 feet long.

We hope to plant vines with lots of foliage on the west and north walls. We are building raised beds [about 1 foot high/ 1 foot deep] along the north and west walls. We would like something that is perennial which will green up quickly in the spring. Though we might plant morning glories, or similar for flowers, but as supplemental foliage/interest, not primary.

The 8 foot sections are the north [brick] and south walls.
While the space is uncovered, it is surrounded by tall buildings. Currently there are 2 trees, a boxelder and a well-established ailanthus.

The 40 foot west wall is ours, and it is stucco. If necessary, we may get latticework to install to protect the stucco from destruction. If there are vines which could grow on the stucco without lattice, that would be great, providing they do not damage it. The north wall is brick, we might get lattice for it, as well.

We’re thinking shade-tolerant clematis, hedera helix, arctic kiwi, or dutchmans pipe…or hops? grapes? ….wisteria [maybe for the tree?] — virginia creeper and hydrangea, but they might pull down the stucco? Perhaps there are others that would do well…

Also: There seems to be powerful winds blowing from the south, enough to break off small tree branches.

Also: another vine that might scramble up the ailanthus without killing/harming it, would also be an interesting option.

Please let us know what you think might be suitable/viable for this space.

Looking forward to your wise advice,

Thanks!

 

(Answer)

 

Thank you for your inquiry.  It looks like you have done extensive investigation as to what vine is the most appropriate for your location.  There are a number of other alternatives for consideration.  English Ivy, Boston Ivy and Climbing Hydrangea are self-clinging and therefore will not need additional support.  The other vines will require support.  I would discourage Wisteria as it is a very heavy vine and needs strong support.  The attached link to landscape Ontario will provide you with some other options and gives details on site requirements for some of the vines you have indicated. http://www.landscapeontario.com/climbing-vines

 

You have thought about growing a vine through the ailanthus but that may not be a possibility. I have included several web-sites that maybe of interest to you.

According to Trees Ontario, Ailanthus is a proven allelopath producing chemicals that prevent the establishment of other plant species nearby. The chemicals it makes can ward off at least 70 other species that could compete with it for space.  Its root system may be extensive and has been known to cause damage to sewers and foundations.

http://ontariotrees.com/mondaygarden/article.php?id=148

However, a report from Harvard University does not come to the same conclusion.  See http://arnoldia.arboretum.harvard.edu/pdf/articles/473.pdf