I am planning to install a shade cloth to protect more sensitive plants that grow under the canopy normally. I have a few american beeches, eastern helmlocks (tsuga canadensis) and some japanese maples that can get easily burnt. I grow my trees on the top a flat roof garage that receives full sun from sunrise to sunset. I live north (45 degrees of latitude), but summers in Montreal, Canada can be quite hot still, especially on a flat roof.
What is your experience with using shade cloth and does it effectively prevent burns ? Does it have a negative impact on growth and internode length ? What product do you recommend to use ?
Here is a picture of the structure I’ve built to support the ombrella, it is 8’ x 9’ and 8’ tall. I anchored the structure with SWR to the outer walls of the garage to prevent wind to lift up the structure.
Here is the kind of shade cloth I am considering now:
I was contemplating first to use old bed sheets cut to the right size but I realized that they would not let the rain pass through and I may get too much sun reduction even with a white fabric.
$148 seems expensive for a 10’ x 8’ piece of 30% shade cloth. I’d check other sites. Maybe greenhousemegastore.com
I bought my 30% shade cloth from Greenhouse Mega Store two years ago and was happy with their price and service. Not that I’m promoting them, but just sharing my experience.
I highly recommend getting shade shade cloth. It was worth the investment. I used conduit and canopy fittings for my frame and ball ties for attachment. The ball ties make it easy to put in early summer and take down in the fall. My frame is for a few benches in the back yard with limited space and placement issues.
When using shade cloth you MUST consider the angle of the sun at the time of day for the area you are trying to get the shade. The sun is never directly overhead except at the equator. You can search for the sun angle by time of year for your location on the web.
I actually have some of my cloth overhang the front and side of a frame to get the shade from midday to late afternoon. The size of the frame would have been too big for the area otherwise. My frames are also just tall enough to walk under; the taller the frame, the more the sunrays are let in from the side.
Hello @gary1218 and @Ace, thank you for pointing out this online store. It will ship to Canada, and even with the currency exchange and shipping charges it is cheaper than the home renovation centers here. Last time I checked with our local horticulural hardware distributors, they did sell small sections to customers, but only large rools (ie 300’ long).
I will definitely purchase a larger cloth so that it can overhand on the South-East and South-West side (I am 45 degrees aligned with the South). Buying a 10’ x 10’ will give me respectively 2 feet and 1 feet overhang, leaving me some room to walk under it. I am 6’3" tall so I needed a minimum height.
Also I chose to build the frame 8’ tall for convenience. I built everything exclusively out of PT 2x4 lumber and having 8’ height and width reduced the number of cuts! I glued and screwed two 2x4 together to make the posts, which gave a much lighter weight than full 4x4 post while remaining quite sturdy still.
My last question, does the wind catch into the cloth during a storm, or can the air flow through a 30% cloth ?
I haven’t had any wind issues with my shade cloth. I’ve been using it for 3+ years now and it has gone through some wind storms.
I tend to over engineer stuff. I installed shad cloth over the bonsai area on 9 gauge galvanized wire, attaching the cloth to the wire with stainless steel spring key holders so the cloth can be moved from out of the way after the dog days of summer are done. this has worked great for three years but I’m not satisfied with the mechanism to move the cloth (cords and pulleys) and need a better idea. thoughts are welcomed.
@Phil.St-Jacques I’ve had no problems with the wind and 30% cloth.
My experience with wind on the west coast has made me appreciate the ability to dismantle or shut down sails in a storm. Do you also have to consider snow buildup over the winter?
@cab_lad_70 I want to be able to remove the shade cloth easily. I definitely have to remove it for winter. We receive on average 2.1 meters (~7 feet) of snow in Montreal per winter. Also we always get a storm in summer with winds over 100 km/h (60 mph).
Attaching piece of 1x2 on top of the shade cloth to your cross members in the top will dramatically reduce flapping and the ability of the wind to grab the shade cloth and take it away. Just predrill some holes in the 1x2 and run screws through the shade cloth into the frame. Also keep the shade cloth stretched fairly tight and round over any edges where you pull the cloth over the edge. It might even hold up the snow, but the garage roof might not fare as well since the entire load will be concentrated on the 4 posts.
I use 40% shade cloth plus an old bed sheet to shield one I’ve only just lifted from the ground.
I don’t usually put mine out until almost midday (unless it’s unusually hot.). Then I remove it around four thirty in the afternoon to let the trees have evening sun. This method prevents stretching. I still put all my maples in full shade during the hottest part of the day. I find the easiest way to prevent billowing and the shade cloth becoming airborne is to use frapping lines criss-crossed along the top.
Yes, secure as Marty said. The wind coming off the building will accelerate and may also come from underneath a bit. Structure looks good. Hmmm, think of the worst wind event and go from there.