Blocking the wind to make the perfect little sunny balcony garden

April 11, 2023 2:34 PM

My apartment gets fabulous sunshine onto my small south-facing balcony. It also gets very windy out there, as I'm several floors up and on top of a hill! I'd like to build a system so I can grow cherry tomatoes, flowers, and other plants without my garden being destroyed by the wind.

My balcony is roughly 3' deep by 12'-6" long, with a sturdy metal grate railing approximately 3'-6" tall.

I'd like to do garden out there with a pleasant chair to sit in (likely zip tied to the railing or the metal decking, since chairs tend to blow around out there), a couple dwarf trees (a conifer and a Japanese maple, ideally), and a small seasonal veggie/berry/flower garden. The building is new and the balcony is extremely well-built and sturdy, made of steel, with lots of grating (for lack of a better word) -- by which I mean the walls of the balcony are made of smaller but still thick and sturdy steel members crossing each other every inch or so at right angles.

I would like to cover the railing with sheets of something clear and sturdy to block the wind but let in sun, like Plexiglass. My questions are:

(1) Is there anything cheaper than Plexiglass I should be investigating?
(2) What's the minimum thickness I can get away with? The cheapest Plexiglass I'm finding is 3/32" for 36"x48" but even then it would take, say, 5-6 sheets and then I'm looking at several hundred dollars, which is a lot of money for me.
(3) Any recommendations for installation? Currently, I'm planning to drill an as-yet-to-be-determined number of holes in the Plexiglass a safe distance from the edge and zip-tie it firmly along the full distance of the balcony railing, which has lots of sturdy natural tie-down points every few inches.

N.B: I rent and don't own my apartment.

Help me make a magical little garden retreat suspended in the sky!

posted by cnidaria to Home & Garden (8 answers total)

Very tired right now, but as an inspiration for future commenters, I will suggest that glass is better than plexiglass for a number of reasons. It might even be cheaper. It does need a bit more advance planning.

If I can, I'll return tomorrow with more practical advice, but I am on a business trip with unpredictable spare time.
posted by mumimor at 3:01 PM on April 11, 2023

Best answer: I put up a tension rod and a light-colored curtain to block sun on my balcony on the hottest days of the summer. You could use a clear plastic shower liner to let light in but reduce the amount of wind coming in. I think wind load is more of a concern if you are trying to use a rigid material like plexiglass, but it seems like vinyl banners also need to be designed with wind load in mind.

p.s. I used burlap to enclose half of my balcony as a privacy screen and to reduce the amount of rain that blows in on blustery days. It is a porous fabric, so no concerns about wind load there.

Mumimor's suggestion of glass reminded me that scavenged/upcycled window frames can be used to make diy cold frames (mini greenhouse set ups).
posted by spamandkimchi at 3:49 PM on April 11, 2023 [1 favorite]

Sheet vinyl is horrible and toxic to manufacture, but cheap. If it tears, mend w/ clear plastic tape. Many places sell flimsy greenhouses of plastic supports & vinyl. These are ubiquitous at varying prices.

A better option is to use bubble wrap, which you can get free by posting on buy nothing groups or freecycle. Make a frame by cutting out a lot from a big sturdy cardboard box(es), and use bubble wrap to make a greenhouse. once the weather is nice, you could use mosquito netting or gauze for protection from wind, boxes will help a lot, too.
posted by theora55 at 3:52 PM on April 11, 2023

Cement forming wire comes in rolls with square openings about 6x6 inches. It hangs easily, cuts easily for trellis, and I imagine vinyl strips would weave through it for windbreak. It has a discrete charm, and would work to also look good. Costco has these 2 feet by six foot metal trellis sections, i have a couple, they also would work for wind break, with vinyl woven in. Here is one set. the trellises I bought are flat panels.Black annealed wire is good for binding garden stuff to railings.
posted by Oyéah at 4:01 PM on April 11, 2023 [1 favorite]

What do your neighbors do? Seeing what survives on their balconies is going to be way more informative than our guesses not knowing what “really windy” means. For example, cherry tomatoes can be grown in hanging planters, which would mean you wouldn’t have to keep a trellis upright, but if it’s sufficiently windy, the foliage is still going to take a beating. My guess is that the risk of catastrophic failure and the expense are both high if you go the route of trying to stop the wind.
posted by momus_window at 4:04 PM on April 11, 2023 [1 favorite]

Polycarbonate roof panels (usually used for patios, sheds, and greenhouses) might work for this. Depending how windy "really windy" is, consider putting up multiple smaller slats with some space in between instead of a single bigger piece, and/or otherwise adding vents to the pieces. Also check if there are building rules about what you can/can't attach to your balcony.
posted by yeahlikethat at 5:06 PM on April 11, 2023

Best answer: Go the agroecological route and try abating the wind instead of blocking it. You can try shade cloth (which is pretty cheap or at least cheaper than plexiglass) and attach that to the railing. It will block some light depending on the "strength" you get but it will also cut the wind and I'd say if it's fastened securely there's less change of catastrophic failure compared to glass or some solid material. If your balcony is south facing you probably won't really even loose that much light. I'm pretty sure you can get shade cloth in 6' widths that you could double over.

Also, a bit of an aside, you say berries, but you may have trouble with good pollination high up on a breezy balcony. You might have to do it yourself or choose plants/varieties that self-pollinate.
posted by sevenless at 6:38 PM on April 11, 2023 [4 favorites]

Does your city have garden centers? I had a friend who lived on the 32nd floor in Chicago and she went to a local city nursery/garden center that suggested plants that were capable of surviving her sunny and windy balcony. They might also have ideas for wind blocking.
posted by sarajane at 9:31 AM on April 12, 2023