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When to use shade cloth

Posted by LeanBean AZ (My Page) on
Wed, Apr 30, 14 at 23:05

I'm a new-to-AZ gardener and was wondering at what temperature I should start using shade cloth on my tomatoes. I have one bed in an area that gets all day sun so I splurged on shade cloth to cover it, but I just don't know whether to leave the cloth on all day, just cover the area by noon, or wait till it gets even hotter. It's supposed to hit 100 degrees this weekend!
Also, since shade cloth from the nursery (Baker in Phoenix, in this case) is prohibitively expensive, I was wondering if others had experience using bed sheets, etc. as shade cloth.
Thank you in advance for any experience you can share with me!


Follow-Up Postings:

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RE: When to use shade cloth

How about cheesecloth.


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RE: When to use shade cloth

I have my shade cloth up all day on my tomato plants. My plants still get sun all morning long as the shade cloth is 8 feet off the ground.

You do not want your shade cloth to touch your plants. Not that yours does :)

I have gotten a lot of my shade cloth at The Home Depot as well as Harbor Freight. The ones at Harbor Freight are finished and have grommets around every 2 feet.
They have various sizes and you can check them out on their web site. It is listed as mesh tarps. I'm not sure what you consider expensive but they have discount coupons usually for 20 to 25% off (which I always use.)
One thing good about shade cloth is that it lasts for several seasons.

Another thing to help your plants in the heat is to mulch all around them.
Good luck!


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RE: When to use shade cloth

Thanks for the Harbor Freight lead. I never woulda guessed! Why no touching?

@LeanBean: that thing she said about mulching? Gold. But once you've done it, do it more.


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RE: When to use shade cloth

@agility_mom, thank you so much for the lead on Harbor Freight, I love how their screens are finished at the edges!
I will be mulching Friday morning before the heat is killer, thank you for the reminder, I've been putting it off. Do you know if I should mulch right up around the stems, or should I leave a little circumference for any reason?


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RE: When to use shade cloth

Leave an airspace around the base of each plant to avoid building a pest highway to the plant's trunk.


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RE: When to use shade cloth

You don't want the shade cloth to touch your plants for a couple of reasons. For one thing it gets hot and it is also abrasive to the plants when the wind blows. You should have a gap between the cloth and plants for it to be more efficient in keeping your plants cool.

I like those finished edges on the HF mesh tarps too. The other unfinished shade cloth is more of a hassle to put on things. I usually use those medium sized spring clamps to fasten the unfinished stuff and they are hard to use.


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RE: When to use shade cloth

I keep 50% shade cloth over the garden year round, it still gets plenty of sun. When the heat hits 3 digits I add more shade over the tomato's. And I have used sheets! My structure is about 8ft high as well and on the west side, so gets sun most of the day, when the late afternoon hits, my neighbors big tree to the west of us shades the plants. I am so happy to say, that this year, I have lots of beautiful tomato's! finally got it right!


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RE: When to use shade cloth

I use aluminet shade cloth, advantage being you can lay it directly on plants for temporary relief. In my case, I don't need or want a shade structure, if I did I would go with the less expensive black stuff. I just use it as simulated cloud cover for some of my Agaves from time to time, by draping it directly over the plants.


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RE: When to use shade cloth

How much is the harbor freight stuff.


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RE: When to use shade cloth

8X10 = $25

8X16 = $28

10X12 = $27

12X19 1/2 = $50

Then you can use the 20 and 25% off coupons.

Here's the link.
http://www.harborfreight.com/catalogsearch/result?q=mesh+tarps


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RE: When to use shade cloth

What about this? Not too expensive. This is what I plan to do. I am also a first time AZ gardener. Seems like the sun has been baking some of my smaller plants over the past few days.

http://www.lowes.com/pd_190671-656-302214_4294610411__?productId=4005761&Ns=p_product_qty_sales_dollar:1&pl=1¤tURL=%3FNs%3Dp_product_qty_sales_dollar:1&facetInfo=


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RE: When to use shade cloth

Thanks. I'd really like one big shade cloth over my whole house.


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RE: When to use shade cloth

What do you guys use to hold up the shade cloth? I don't have any tall trees in my back yard yet. I bought one of those 3 sided sun sail things, but I haven't used it yet.


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RE: When to use shade cloth

iAndy, when I built one of my beds I put in PVC pipes to make a structure I can lay the cloth on (see photo), then I use these really strong plastic clamps to attach it.
I think you can easily retrofit any bed the same way, or bury some PVC pipes in a "hoop" style like I see so often. On another bed I'm going to attach cloth to the 8ft bamboo stakes that my tomatoes are climbing, but that could backfire on a windy day, turn into a sail, and tear everything out of the ground, so I'm still thinking of alternatives. PVC is cheap, so it's not too much of a risk to try out different things.


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RE: When to use shade cloth

Here's a follow-up picture of that same bed now, and it's a little hard to see but the shade cloth is already attached to the outside.


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RE: When to use shade cloth

I was going to buy some of those things called "plastic snap clamps." Do they carry them at Home Depot. I know you can buy online but I wonder if they really hold. I have the PVC pipe like you have on the raised bed. Will it create a wind tunnel when the wind kicks up,


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RE: When to use shade cloth

I like that hoop idea. Much better than what I was planning on doing. I have some plants I want to shade that are in large pots (about 3-4 feet tall). I wonder if putting rebar into the ground where I attach the pvc pieces will work.

What size pvc are you using for that and is it easy to bend?


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RE: When to use shade cloth

iAndy, that is a 4 x 4 bed, so I used 10 ft long, 1/2in diameter PVC pipes, and with two people they are extremely easy to bend. I also thought I would need to slip them over a piece of rebar, but in the bed they push against the sides and that holds them in place. If you're putting them freestanding in the ground, a little piece of rebar would be really smart, and please, if you end up going that route will you tell me if it worked?


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RE: When to use shade cloth

LeanBean, we have used the PVC and rebar and it did keep it from blowing away in our wind extremes. My husband had about 9 inches of rebar and put the PVC over it..I now use a pergola with 50% shade cloth, but sometimes we still use the PVC and rebar to cover a tree with bird netting or to shade something new in the yard, etc..


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RE: When to use shade cloth

toucan, just catching up to this thread. I purchased those plastic clamps and they work great but are a bit pricey when you consider that plain old binder clips from Staples work just as well!

I love the pvc hoop idea. I did that too but did not think to go diagonally and use only two. I'll post a pic of my bed. I use the pvc and those clips on the pvc tubes for mosquito netting to keep the birds and grasshoppers off the veggies.


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RE: When to use shade cloth

Two answers to that question. Plants shut down by closing of their pores (spicules) on the undersides of the leaves when the temperatures get above 85F to conserve water. This turns off photosynthesis. So the plant goes into a rest mode until the temps drop below 85F.

There is some fudging if there is transpiration and shade to keep the air temp below 85F in the area of the plant.

So the first answer is when the temps start climbing above 85F is the time to start considering erecting shade cloth.

Western shade seems to be most important. Overhead second. I buy burlap of a decent weave (not too fish net, not too dense). Home Depot sold 200' rolls. . . but I have not noticed any in two years and my roll will run out this year. Nice thing about burlap is it is compostable. Lasts about three summers before it rots.

Old sheets can work. But they will not pass air (which may trap heat) and may act as sails by the winds.

The second problem for a plant is solar intensity. I am still not sold on the claim that plants saturate out around 10:30AM in the summers here and shut down. The idea is eastern and overhead and (maybe if not already saturated) western shade will extend the growing of the plant in the summer (I presume until an under shade temp above 85F is reached). Not sold because I have yet to see any data backing up the claim. I do know too much solar intensity creates a great deal of excess toxic reactive oxygen molecules that can severely harm the plant. Either way though the solution to temp or intensity is partial shade.


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RE: When to use shade cloth

Mary, what the heck do the two security doors provide?


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RE: When to use shade cloth

Yup, I use 2' half inch ribbed rebar (#4, I believe). Drive about halfway into ground. 1/2" id PVC slides snugly right over it. If you want the PVC to last many years (as opposed to about 4) then paint them first with a light or white latex paint. Put them and shade cloth away in fall (Sept-Oct) unless it will be used to hold netting, frost cloth, green house/hoop cover.

I even use two upright PVC poles for western shade on some trees that only require only western shade to prevent afternoon wilt. Winds can blow them horizontal, but never had any harm the tree or come out.


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RE: When to use shade cloth

Mary, what the heck do the two security doors provide?

HI FN, Those security doors keep keep the bed secure from bugs, by gum!!

Actually, they are/were trellises. That was my attempt to follow Catherine's lead in letting the tomato plants sprawl. I thought they would be good for keeping the vines off the soil. They were but fertilizing was a real hassle and I've abandoned that idea. This year I've gone horizontal with a couple types of cages. I may try the sprawl again. I've been spraying beneficial nematodes to battle a brown dog tick problem and I'm hopeful it will also get rid of the 'hoppers and squash vine borers. I'm willing to spray the BN's twice or three times annually for a while if it does the trick, then I'll be more comfortable sprawling the vines.

Thanks for asking. m


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RE: When to use shade cloth

Might try tightly streching a trellising net across the bed HORIZONTALLY at a height you think best for your tomatoes and let them grow through it (which they readily will) and then it will support the plant.

http://www.burpee.com/gardening-supplies/garden-growers/supports-ties-and-fences/jute-trellis-support-netting-prod22499.html?omn2pd=sh&catId=

Here is a link that might be useful: or Amazon for longer


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RE: When to use shade cloth

FN, wow, I wouldn't have guessed 85F was hot enough, I guess that means that my plants that haven't fruited yet are very unlikely to. That's bad news since I have five plants without flowers that were given to me late in the season and I couldn't not plant them! I think I'll try your technique with rebar next time as well, since I'm pretty nervous about the winds during monsoon season.
Mary, I love your bed and your style of hoops!


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RE: When to use shade cloth

Thanks LeanBean, the setup is working well. I've had several renditions of the garden beds before we hit on this one and I'm happy with it. The mosquito net is for keeping birds off the ripe tomatoes and, in the above pic, trying to keep the 'hoppers out.

FN, the reason I did not do the lattice again was that it made mulching and fertilizing difficult. The netting with have similar issues. But I like the idea.


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RE: When to use shade cloth

Here's what I'm doing this summer for shade. I bought this last year when it was reduced in price. It doesn't completely block out the sun, so it seems nice for the plants under it.


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RE: When to use shade cloth

I got my shade cloth now. I picked it up at lowes. They have a great set up. You can ask for any length and they will cut it for you. For $10 I got enough for 2 raised beds with the PVC pipe set up like Marymcp.

Fascist: I have been spraying water and or solution of fish emulsion on the leaves. Would that help cool it down enough to get the flowers to fruit? I know water on the leaves in other climates is a no no but doesn't seem to create the same issues here in our dry climate.


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