I have often seen vining plants used to create tunnels and of course grapes held just at picking range overhead. It led to the idea of creating a living 'shadecloth' or 'suncloth' structure as part of a commercial permaculture nursery. As I have further explored the concepts of the permaculturegreenhouse and what might be related to it, the possibility of making this structure seems entirely viable. The real trick will be in getting something that grows well enough to cover a 20 X 20 overhead area at least 8 feet up. Depending on the speed of growth, some annuals might work, though I am ever more thinking a perennial is required to do it effectively.
I could see this going in one of two ways. First would be something that grows quickly and covers a wide space along a side-wall as well as growing across the 'roof' lattice. The second would be something that grows up a post at each of the four corners and then covers the 'roof' lattice with growth. In the second instance, a living wall would then be grown along the side(s) prone to the most wind and ill weather. I've collected a number of potential contenders after ruling out certain ones as being too thinly spaced (runner beans) or too slow growing (ivy) as well as potentially weak ability to properly grow over the 'roof' lattice. What is left aren't necessarily ideal candidates either, but just some that haven't yet been thinned out of the herd yet. I am hoping that some of you might have experience with some of these plants and can immediately rule out or recommend some of the options.
Wall-Only Plants bamboo
rose of sharon
Vines for the 'Shadecloth' hops (Beautiful coverage, but cause drowsiness)
blue chinese wisteria (one of my top choices atm)
crimson glory vine
five leafed akebia
One thing that comes to mind is planting so you get sun when you need it and and shade when you need it.
Grow cucumbers up the wall of a greenhouse to cool it, shade it in summer, but you'd get the full sun in the winter months. A perennial vine that's deciduous could do the same without replanting every year.
I have been pondering this idea myself, with two layers of snow fencing on the roof, one to support the roof plastic against snow loads and another for the vines to run on.
Hardy Kiwi might be another vine to consider.
Annual vines could be planted in hanging containers to give them a "headstart" . I hear sweet potatoes are prolific producers of foliage, but I am not sure if they climb.
Here are a few perennial vines that I found out about online:
Scarlet Runner Bean is a legume that is native to Mexico.
Passionflower has cool big three-dimensional flowers, and it is native to the southern portion of the USA.
Arhat Fruit is native to China, and it has round sweet fruit.
What percentage shade do you want underneath? Are you putting something people-centric, like a cash station or potting bench underneath? Overripe grapes dropping into the customer's pocketbook ≠ return business.
Four thoughts: 1) honeysuckle-we had one that reached to the deck above a one story garage, 2) mixed species so something is interesting more of the season, 3) roses with useful hips, 4) and this one would take a ton of work but in a decade or so would be so cool, a ginormous espaliered pear wall. Need to find a variety that's self-pollinating since there aren't bees indoors and has a lot of vigor to reach that high. And a vine that could grow with it compatibly while you waited. But the trunk would be beautiful even when bare. A super vigorous crab apple might do the trick too. People would come to shop just to see it in the spring.
i love this idea and have done similar stuff.
i will usually only grow edibles, but i see by your list you would grow some ornamentals, which gives you more choices.
rose of sharon is nice, as well as any other hibiscus
thimbleberry gets really tall
vining /climbing plants:
coral vine (is this the same as queens wreath as you listed?)
wild grapes, cultivars maybe too but the wild ones are more suited to this
clematis, is so lovely i would grow it even though its not edible
Wayne - Cucumbers did come to mind, though the rate of growth might be a little slow for what I am thinking. My current leanings are towards something perennial so that it could drop leaves in the winter, but sprout new ones right away in the spring for immediate shade.
William – I actually forgot about hardy kiwi! Thanks for that reminder.
Dave – I hadn't thought of the second two either, but already ruled out Runner beans because of personal experiences with them making me think it would be hard to get good and solid coverage with them.
Ann – The percentage I am looking for is probably between 40 and 60 percent overall coverage and most likely there will be only plants under this area with other locations such as sales and potting separate. 1) Vining honeysuckle might be an option. I mostly have experience with bush honeysuckle, which chokes out all other living things around it. I'll have to look into this one. 2) Very true and a good point. 3) I do love rose hip tea, but I would think thorns on an area where customers would be going through to pick out plants might be a bad combo. 4) Interesting suggestion with the pear, though it would take years before it could be considered usable. Long term, I may take up that suggestion as it sounds like a stunning display, though in the short term, something a little quicker growing would need to be in place. I would think any vine with enough coverage would also end up competing with the pear. This shade area would be outside rather than inside of a greenhouse directly, so bees wouldn't be an issue. One of the reasons I was favoring wisteria was the draw on pollinators in addition to the scent and appearance.
Leila – Thank you for further suggestions! In years past, I was someone who felt strongly about the idea that every plant I grew had to provide either food, medicine or a material benefit to me. I hated flowers for the sake of flowers, etc. I chose to include ornamental varieties these days after a lot of thought on how things can unexpectedly play off of one another as well as there being value that is unseen or indirect in certain plants. At the very least, any plant I grow is going to have the shade benefit in this case, but some may provide food, pollinator attractants or even just something interesting looking that draws in more customers. There might be some other unexpected beneficial interaction as well that I can't predict yet.
Pete – Gourds are another good plant for spreading out, though might have some of the same issues as the cucumbers. They tend to grow linear, but if I lined enough up, it would work well I imagine. As for what zone, presently zone 9. Ideally, I would like to be in zone 7, but it may end up being zone 6.
As a side benefit from the shading aspect, is that many customers may see this, and think "What a great idea for the gazebo/patio/or where ever they may want more shade in the summer months". You might create a new market of selling transplants of your vines.