Hot direct sun + root zone temps.

Different pepper types react in different ways to heat, and you are noticing the difference. Leaf droop can be considered "normal" during the hottest months of the year, as long as they are on a regular watering schedule, then it's no cause for concern.

Just be careful not to overwater either, that's when you get nutrient lockout, yellow leaves, and plants that quit growing for a while.

This post was edited by sjetski on Tue, Jul 9, 13 at 21:28

Okay well I guess they aren't over watered, as they are my greenest plants. I have hope to pick some Poblanos this year!

My guess is that since they are the "newer" plants, you recently repotted them. They probably are still suffering a bit of transplant shock and haven't developed a good root system in the new soil yet. I would probably get them more shade during the heat of the day until they have a chance to grow some feet.
That would be my first guess anyway.
Bruce

Well newer is relative. The originals were planted around May 20th... and I think the newer ones were planted two weeks later. Should have a good enough root system by now. At least thats what I would hope. As of this morning, the Thai perked up but the Poblano is still a little sad looking. We got a rainstorm last night.

are they in pots, or in the ground? if they're in pots, try rotating their positions from time to time, see if putting them in a different place helps. I was having similar issues at one point, where 2-3 plants were looking unhealthy while the rest were fine. then one night I happened to be outside when the sprinklers were going, and discovered that the problem plants were getting nailed by direct sprinkler spray a few times per week. so I moved them away from that spot, and now they're the best looking plants I have.

also, pictures help when diagnosing problems.

There is a phenomenon late in the day when the sun has set and the plants, not just peppers neccessarily, will look really wilted. They are just in a brief state of dormancy.

It's only a natural reaction to water the plant. Don't.

This is how people end up over-watering their plants. If they are still wilting by morning, then give them water.

One method to ensure watering is using a bottom tray.You can fill the bottom and the plant can get what it wants when it wants. However, I am not convinced that doing this exclusively is a good idea. I think some watering in the top must be included from time to time. Otherwise, you might start seeing the water starved upper roots breaking through the surface.

Another person suggests the "wilt then water" method. I personally think this is a good way to do it if you haven't quite got the hang of watering yet. The good thing about this is that the plants won't die if you water them promptly, but will look very droopy. Again, you have to differentiate between evening droop and thirst droop. Another good thing is that by stressing and relieving the plant like this is supposed to be good for it. There is one drawback I have found by doing this method. A few weeks later, some of the foilage afflicted most from thirst does tend to suffer prematurely from diseases (eg. curling) and drop off. But these tend to be isolated cases and don't affect the plant as a whole.

This post was edited by SgtPepper on Wed, Jul 10, 13 at 17:44

They're in pots on my deck. I will try moving them around a little and see what happens. I would take pictures but they're looking fine right now, in spite of a rain storm last night.

SgtPepper, I think you could be right on the money for some of the times when they are wilty, I have noticed a few nights where they looked like that and were perked up nicely in the morning. But that doesn't account for the whole time. But, maybe there is something like Judo suggested, and they're the getting the most sun and can't take the heat.

They are doing it again. I have attached a picture of the poblano. I'm guessing it is the heat. No pods on the poblano or thai, and most of the other plants keep setting new pods. Also the poblano and thai have some nice funny shaped leaves, like the leaf curves to the side. Not all of them are like that.

I would check the humidity. It could be just long periods of overly high relative humidity. Nothing to worry about unless it persists for days on end.

Thanks. It has been highs in the high 90s with about 80% humidity all week. And as usual, they perked back up over night.

Also, what about the funny shaped leaves? They look like they curl to the side. Not all leaves are affected, but some of the newer leaves are whats affected.

The thai photographed better for the misshappen leaves. Same look on the poblano. Also noticing some crinkled leaves as well.

Could be the effects from the humid conditions. There's not a lot you can do about high humidity. There are dehumidfiers, but good ones are expensive.

You can create home-made dehumidifiers, but I have tried making them with no detectable results.

Someone else here might have a better idea and perhaps have a different diagnosis of the problem.

I think the best thing to do about the humid conditions is just wait it out. Heat wave should break tomorrow or sunday. Hoping that helps these guys do a little better. Funny though how one of my cayennes, both hot cherries, and both hot portugals are still setting fruit nicely, but these guys refuse to do so in the heat and humidity.

I think humidity, not only is not the cause for wilting, but it can actually help the plant from losing too much moisture.
at high temps combined with dry air, plants ten to wilt worst.
IMO

The strange leaves aren't exclusive to the thai and poblano. Some sort of this is on almlst all of my plants, and this leaf was pulled from my vertically challenged hot portugal.

I have all of my pepper plants in pots. Only one seems to stress out about heat. It is one of 3 Aji Limons. It has become my "special" pepper that demands pampering. I just take it into the AC on a counter until the direct sun is gone, then back with the rest... I do not add more water than the others. They are all podding, so I tend to heat/water stress them to develop hotter pods.

The above picture looks like sun burn and not anything serious since the leaf is a good deep green otherwise. I pick those leaves off so the plant can send energy to the good leaves.

Okay so it sounds like I should have tried to move them around a little for the heat wave we got. All the plants look pretty good today, so they're staying where they are for now. Hoping the cooler weather brings some pods on the poblano and thai. Everything else is doing pretty good with growing more peppers.