The only peppers I ever really have sunscald on are bells. Occasionally an anaheim. Upper 80's? No need really except for the bells imho.

As far as the brassicas-- sure... you can harvest into the summer, but it's not the sun that causes cold weather veggies to bolt -- it's the soil temp. So mulch would be a better investment.

With the lettuces and spinach, same thing. Although shading in the afternoon and bolt resistant varieties also helps..

I only use shade cloth for peppers for a few hours of the day when the temps get way up there -- over 95F. And when I plant my cool weather seedlings in the late summer when it really starts to heat up here.

It's not meant to be a permanent cover because, like you asked, brightness of sunlight is important. A few hours a day won't hurt though. As long as they get plenty of "cooler" direct sunlight.

I'm just an amateur though. Let's see what the experts say. :)

Kevin

You shouldn't need shade cloth that far north for anything if planted at the proper times. If your plants are getting sun scald then most likely they aren't hardened off well enough before planting.

Pepper plants, properly hardened off, don't get sun scald even in zones much hotter than yours.

Brassicas and other cool weather crops that are planted in the heat of summer might benefit from some shade cloth but is is the hot soil temps that trigger bolting in them so heavy mulch would be just as important.

Dave

Wow. I'm in Central Texas. We get weeks of over-100 degree weather in the summer, and I've never seen anything like sunscald on my peppers. Keep them watered, and well mulched. You may have a problem with peppers with temps in the high 80s, but sunscald isn't it. Peppers are among the most heat- and sun-tolerant vegetables.

Brassicas are another matter, but as noted, it's temperature and not sunscald that's problematical for them.

If we're talking about very young transplants, you might just "harden" them in part sun at the higher temps before transplanting.

Amen, Danin,
I have gardened in GA for several years never experienced such thing az sun scalding.

AsDave mentioned, if you bring a plant from a different environment into garden, they need to be hardened off.

When I gardened in Z 7 I never had trouble with sunscald on peppers, but in high elevation Z 6 I do. Most years I use clothespins to attach pieces of lightweight cloth to tall poles, so the shade cover flutters about a foot or more above the peppers. Last year I used a double thickness of tulle with wear-and-tear holes in it, and it worked really well.

These were orange Valencias that eventually produced an excellent crop.

The containers I'm using for lettuce and other cool weather veggies I'd like to grow in the summer are white, and gray.

The white containers are 18 gallon plastic rectangular storage containers; I also have for white containers small circular 3 gallon plastic containers (they're about 11" deep and about a 10" diameter). Last but not least for the white containers I have circular 5 gallon plastic containers.

I also have some translucent containers; some are clear the others are blue (like a turquoise).

Would I be able to use these containers to grow cool weather veggies in the summer? I'd be harvesting them in early July; would it be too hot?

I was thinking of using floating row covers for eggplants and pepper plants because aphids love them.

I don't do much container gardening, but cool weather vegetables are sensitive to soil temperature as well as air temperature. I suspect that in the northern summer (where I used to live) container soil in the summer gets much warmer than ground soil. Unless the container is pretty big, the container soil temperature will follow the air temperature. For containers of the size you're referring to, especially if the containers are sunlit, even white ones (black ones would be much worse), by the end of a day with the temperature in the high 80s, that's the temperature your container soil is going to be, if not higher.

You might check on this, but I believe that the optimum soil temperature for cold season vegetables is around 60-65F. That doesn't make them easy to grow in the summer, but it seems that it would be harder in containers.

They shouldn't get sun scald unless you are watering the leaves.

Would the temps for container gardening be reduced if I were to use a container whose material is something other than plastic? The first thing that comes to mind is something porous like a smart pot; I've also seen plant bags for container gardening that use a material similar to felt.

Are there any simple ways I can regulate the temperatures of the containers and cool the plants down?

People have suggested putting the container inside another container, but this isn't practical for me; it's also been suggested that you could dig a hole and put the container in the hole, but again that's really not practical for me and sort of defeats the purpose of doing container gardening by putting the container into a hole in the ground (to me anyway).

kawaiineko: The larger the container, the better chance of regulating temps whether it's plastic, wood, clay, etc. That, and a good 2-3 inches of mulch. I use oak barrels and raise them on cinder block with lots of drainage holes. At the end of the season when I pull my plants, there's a nice little herd of worms in them. So, I know that the containers couldn't have gotten TOO hot.

zackey: when I was referring to sunscald on bells, I wasn't talking about LEAF burn -- I was talking about scalded shoulders of the fruits themselves. Green bells, I'm sure, wouldn't be a problem. I don't grow them. But colored bells, between the long ripening time, the meaty fruit, and the dead of summer heat, occasionally I have a couple with burnt shoulders.

Kevin

Are there any simple ways I can regulate the temperatures of the containers and cool the plants down?

Sure. Lots of ways. Thick layers of mulch is recommended all the time for just that purpose. You can also insulate containers by wrapping one of the many forms of insulation around the outside of them.

The material it is made of makes little difference - plastic is as good as anything else.

But you are only talking about 80 degree temps so your problems of heat control are minimal compared to what all the mid-west and southern half of the country have to deal with - temps as much as 40 degrees higher than that are common for many. In other words you are worrying about problems that you may not even have.

Dave

I don't think a layer of mulch makes a lot of difference in temperature regulation for a container. In a container, the heat is coming in from all sides, not just at the top.

But yes, wrapping insulation around the containers will help some. Seems like a lot of trouble to go through for brassica's, though.

Again, once you keep the sunlight off the containers (that's first priority), keeping something moist on the outside will do a great job of cooling. If you want to do some work, instead of wrapping with insulation, I'd wrap with or glue on some carpet, towel, or thick fabric. That way, whenever you water, you simply drench the fabric and ideally keep it somewhat moist. Think dewpoint. That's the temperature that wet fabric (and to some extent your container) will be at. Unless your relative humidity is enormous, your dewpoint will be considerably lower than the air temperature. If the weather gets a lot cooler, just let the fabric dry out.

I do get sunscald on California Wonder because they don't have enough top foliage cover. I've switched to Yolo Wonder, no scalding (which usually only happens at 95 and higher here). Marconi and most traditional italian sweet peppers and all the hot peppers I grow - none of those get scalded.
A trick a local farmer taught me is to plant the pepper on on the side of taller veg (like tomatoes) that will give afternoon shade. That works very well.

Um what could I use as insulation on the outside of the container?

Also a very dumb question but you said if you were to wrap something around the container that's wet, it would reduce dewpoint (as you said the temp of the container). My other question about wrapping something wet around the container, would you wet it before you wrap it around the container, would put it already wet on the container, or does it not matter either way?

The problems I'm referring to with sun scald is on the foliage not the fruit of the plant.

You're not reducing the dewpoint. The dewpoint is the dewpoint. It's a function of air temperature and humidity. You can see it in your local weather report. It's a property of the air around the container (and you).

Excuse my lesson here ...

When you're wet, you feel cool, right? That's because as the water on you evaporates, it cools. The warm molecules of water depart, leaving the cool ones behind. The dew point is what the temperature would be if the humidity were 100%.

See here ... http://www.dpcalc.org/

As you can see from that handy calculator, if the air temperature is 90F and the humidity is 50%, the dewpoint is 69F. So if you're at the pool, and you're wet, as the wind blows on you, it's going to feel like 69F. If the humidity is lower, you'll feel colder, right? Ever been wet in the desert? Ouch! In fact, that's why air conditioners in the desert southwest work inexpensively by blowing air over water -- "swamp coolers". That only works well when the humidity, and the dew point, is low, which it usually is in the desert.

So the idea is to keep your container wet, so as the breeze blows over it, the container will be cooler. It's hard to keep a plastic container wet. It dries off fast. But if you cover the container with a thick layer of absorbant cloth -- a towel, or a piece of thick rug, you can soak it with water, and it'll stay wet for a while. When it dries off, just hit it with the hose. As the water slowly evaporates, the cooling cloth will cool the container.

That's why a porous planter is a slick idea for this purpose. The moist soil inside keeps the outside a little moist, and so cooler than the outside air. With a porous container, you don't need to be wrapping towels or carpet!

I've never really heard of someone trying to cool a planter, but if you're serious about it, this is the first thing I'd try.