shade cloth question

Can anyone give me guidance on when to use a shade cloth?  Do you shade your plants when it reaches a certain temp, and if so, what temp?  Once we reach the hottest time of the year, do you leave it on all the time?  Or do you take it off for periods to give the plants some direct sun?  Any advice appreciated.  Thanks!

I can narrow it down to 2 general guides. #1 -When it hits 100*F, the shade material goes up. Anything potted goes into shady areas. #2 - protection from the western sun is my priority. The morning sun, before the day heats up, is okay.

Plants can be like people. When it is hot, we don't like to do much. Keep hydrated. Cover the soil with mulch to keep the soil cool and reduce evaporation. The plants may not set fruit (tomatoes, eggplants, peppers, etc.) but they will survive and start to produce again when it drops under 100*F. Other crops just aren't appropriate in the hot summers. Lettuce, bok choy, coles will bolt (produce flowers). That's the end of them. They are better California winter crops. I hope this helps.

Yes, that helps a lot.  Thanks!

I have used two methods to shade my gardens, one is using used recycled sheer curtains which shade very nicely without blocking a lot of uv light.  Then for my greenhouse, I bought a commercial shade cloth that is white but blocks 30% of the sun and kept my greenhouse within 5-10 degrees of the outside temps.

Both work very well and when you're over 95-100 the plants really enjoy the break from the sun just like we do :-)

Both my wife and I work, so nobody is home to water the garden during the day.  In the middle of the summer here in Maryland, my plants will wilt if they don't get a mid-day watering.  Since I can't do that, I use shade cloth.   That keeps the plants from wilting until I get home and water them.

I use a shade cloth that is supposed to be 60% to 70% sun blocking. Here in Phoenix I do not deploy it until the temps go above 95F, once they do I leave it deployed until temps drop back below the mid 90's and on cloudy days (not many of those here in Phoenix). I believe the 60
% to 70% sun block rating of the shade cloth is high as my plants grow well under it and I can feel the intense sun while standing in the shade.

I tried shade cloth last year in Las Vegas, and honestly didn't see much difference.

Things like tomatoes are working off ambient temps as far as I can tell - if it's 95 out, then it's 95 - they aren't gonna set fruit.

Also, shading melons and peppers and other heat-loving plants just pissed them off.

Consistent watering was much more effective in keeping my plants happy.   But again, this was just my experience.

(in other news, my radishes are bolting, of all things, hahah)

I believe that plants wilting is their way of surviving the heat until the sun sets.  Their roots should be deep into the soil. Maybe that is why it is better to soak thoroughly rather than water every day.

Has anyone experience of not being able to water one day, or more? How long can plants survive without watering?

Anyone prepared to sacrifice a plant or two?

I just posted that I have seeds sprouting under the shade cloth that planting guides say shouldn't occur.  When I see temps about to hit 100 the cloth goes up.  When I see 100 is basically done the cloth comes down.  4 months of the circus tent down here in Phx.

I may not get fruits setting but as soon as temps drop, everything that stayed alive (tomatoes) has a huge fall crop.

@ pictures below show my success with a complete covering the entire season. I started when adding plants and sowed seeds direct. I will maintain one bed with a cover forever.  I started late, cold weather, and I wasn't able to well maintain my beds this season. My kohlrabi came up nicely, broccoli as well, however a little sparse. all herbs did and doing well, I planted way to much, did that for experiments. One surprising item is the way celery is growing, it's doing nicely, smelling delicious, can't wait to pick it..
I started this in beginning and since I have found a cover that's very durable I am sticking with it for non pollinating plants. Some issues with sow bugs, milipedes, and earwigs, will tend to them as time allows.

By the way.. I was away for 6 days and no rain, beds only used moisture retained my Mel's Mix..

Yep.  Can't wait.  

Even if shade cloth can't change temperature enough for things like tomatoes to fruit when it's just too hot, if it can prevent sun scorch on leaves or fruits, that's still very valuable. I get a lotta scorched veggies where I live.

Bump. Getting close to the time to put up shade cloth in some Regions. There are 47 Threads on Shade!

(I use sheer curtains and 75% shade cloth from Home Depot.)

sanderson wrote:Bump.  Getting close to the time to put up shade cloth in some Regions.  There are 47 Threads on Shade!

(I use sheer curtains and 75% shade cloth from Home Depot.)

Sanderson were your plants still producing under the shade cloth during the month of June?

Yes, bountifully!  And, no sun scald.  I just picked 6 large, beautifully dark green poblanos today.  Plus, put up 7 pints of tomatoes.  Beans, tomatoes, varieties of peppers, cucumbers, eggplant.  I'm in heaven this year.  Best thing I could have done was to add that extra 12'x18' shade cloth this June.

All that said, are you having problems with shade cloth or just wondering if it might be something you want to expand on?

those are great pictures. I wanted to hear the results of the different plants fruit your are getting under the cloth. I see people putting cloth up, but don't really here how well the plants are producing.

Thank you for the answer and those great pictures. what's the temperature high today?

Has, The temps are around 100 +/-. From under the shade, I've been harvesting flawless big peppers, tons of patio tomatoes, cucumbers, eggplants, tons of green beans, even growing some Black Beauty eggplants for the first time in 6 years, and hot pepper varieties (which are normal for me here).

I can't do anything about fruit set in the severe heat but the shade cloth seems to help when it's under 100*F. The whole back yard is a little cooler with the cloth. The section of the BTE strip on the east side of the house gets shade starting around noon to 1 pm and the cantaloupe, cucumbers, yellow and zucchini squash, and pole beans are producing decently. The 9 indeterminate tomatoes in the BTE strip that are exposed to sun until 3 or 4 pm are loaded with fruit and I have to grow them at 4 stems per plant for self shading.

I hope this helps.

sanderson wrote:The 9 indeterminate tomatoes in the BTE strip that are exposed to sun until 3 or 4 pm are loaded with fruit and I have to grow them at 4 stems per plant for self shading.

I hope this helps.

Wow, that's a great harvest. what do you mean 4 stem per plant?

The Mother stem and 3 daughters (suckers).

sanderson wrote:The Mother stem and 3 daughters (suckers).

are you saying you keep the mother stem and 4 suckers, then pick off the other suckers? Would you post a picture? I have not pick off any suckers, so there a lot of foliage to protect from sunburn.

These are terrible photos of the BTE strip tomatoes.  Each trellis frame is 5 1/2' tall and 6' wide.  The tomatoes start out in cages and are then supported over head with stretchy garden tape.  The lowest leaves were trimmed once but will not be trimmed until the low growing tomatoes are harvested.  The "daughter" stems are suckers that I selected to let grow when the plants were short.

This Mortgage Lifter is exposed to sun until late evening. There is the mother stem and maybe 4 daughter suckers that were selected when the plant was short.

This Mortgage Lifter starts getting shade the earliest and has bigger leaves. Mother and 4 daughter stems.

Here are 4 plants, L-R Better Boy, Cherokee Purple, a mystery tomato that grows +/- 1 pound fruits, and Another Cherokee Purple. I have lovingly named the mystery tomato "Ox". These 4 plants have the mother and 3-4 daughter stems.

sanderson, do you ever take the soil temperature ? I don't know if people realize, soil temperature can easily exceed air temperature if in direct sunlight. Mulch and shade cloth can make a big difference. Here have to watch the dew point which is going into the 70s this week for a few days in a row. Rain and high humidity can lead to fungal problems here.

Dan, I mulch so the soil is nice and cool in the summer. I haven't taken the temperature but I will check a couple of bare pots without plants to see what it is.

I do check the Mel's Mix temps in the spring to see when they reach 60*F so I can plant the seedlings I started indoors.

I did an experiment today using the soil thermometer for checking the soil temperatures in the various beds.  We have had endless heat in the high 90's with very little to no rain for the past couple weeks. All of the five beds tested have the same soil blend, and all are on the same drip irrigation zone.

Bed one has open soil since I harvested the beets a few days ago, and I have not re-planted the bed yet. The soil in that bed at 3" was 95°F, at 6" was 87°F, and at 9" was 72°F.

Bed two has a heavy coverage of green beans growing, which heavily shades the soil. At 3" the soil was 86°F, at 6" was 70°F, and at 9" was 66°F.

Bed three has peppers growing in it, with a living mulch of Crimson Clover on it. At 3" the soil was 87°F, at 6" was 80°F, and at 9" was 74°F.

Bed four has tomatoes which are mulched with straw about 5" thick. At 3" the soil was 80°F, at 6" was 71°F, and at 9" was 65°F.

Bed five has various vegetables growing in it, and is mulched with compost about 3" to 4" thick.  At 3" the soil was 82°F, at 6" was 75°F, and at 9" was 68°F.

It appears from this small experiment that the heavily mulched soil remains the coolest in the hot sun, while the shaded and living mulch is a close second. The open soil, though, is greatly affected by the high heat.  Since all of the beds are watered the same amount, and at the same time, I decided to check the moisture level of the beds as well. The soil moisture meter showed that the beds with the straw mulch and compost mulch registered high on the "wet" end of the scale. The beds with the bean shading, and the living mulch registered just over the middle of "wet" end of the scale. The bed with the bare soil registered as "moist".  The drip irrigation system rand from 5:30am for 45 minutes, and the temperature test was taken just after 1:00pm, so there had been 7 hours for the water to be absorbed by the plants and the soil.

Great experiment OG thank you for sharing it