Quick min/max for varieties?

[estación seca]

Mealybugs aren't widespread outdoors. There are lots of mealy bug predator insects outside. Mealybugs arrive with plants you buy. Aphids are outdoors everywhere. Blast them off your roses with a water spray or soap/water spray or isopropyl alcohol spray. They always come back because they are native to your locality. Spider mites sren't native to North America but are established in most urban areas.

[Ray]

@RoseSD - I think the heat simply shortens the reproductive cycle, allowing the mealy bug population to grow much more quickly. You probably saw that because you didn’t truly eliminate the population the last time they infested your plants.

@estacion seca - maybe mealies aren’t an issue out there, but here in the Cape Fear region of NC, they are definitely present outdoors, and seem to be particularly attracted to a pyracantha. A couple of summers ago, our bush (in a part of the yard we only visit when we mulch, or the dog wants to poop there…) it was so infested, it looked like it had been sprayed with artificial flocking used to simulate snow in Christmas displays.

[estación seca]

Mealies and scale are outdoors, but those are often different, native species, and not the ones on our orchids. Later I'll provide a photo of cochineal scale on cactus.

[HiOrcDen]

Originally Posted by estación seca

I know you won't like this, but the question is far too simplistic and it isn't possible to answer. Plants are complicated living organisms. Temperature tolerance varies with all the other growing factors.

What is the acceptable temperature range for people? I'm old, but still comfortable working outside in my garden all day long in the sun when it's over 110 F / 43C as long as I have plenty of water and beer, but other people can't do that.

What do you mean by hot? That means different things to different people. I heard a talk once by an extremely famous British succulent grower and author of dozens of books. He described the temperatures during a trip to desert habitat in northwestern South Africa as unimaginably, blisteringly hot, and he could not believe plants would tolerate that. Later I asked others on that same trip how hot it was. They told me it was around 90 F / 32C, which to me is a very mild temperature.

If nights cool down most orchids will tolerate higher day temperatures. This is probably your most important thing to consider.

Well-watered plants tolerate hot days better than water-stressed plants. Water in the evening, and spray all your plants so their leaves are wet. The evaporative cooling will further cool plants and make them happier. Your relative humidity is low enough this time of year it won't cause fungal issues.

Extra shade helps plants tolerate heat. Sun plus heat quickly burns leaves unless there's extremely good air circulation, so don't allow that to happen. Some of the plants you mentioned are shade growers.

Speaking of air circulation, placing a strong fan on your plants will help keep them cooler if they have any outdoor sun exposure. The moving air carries off the heat formed when sun strikes the leaves, and the leaves stay at ambient air temperature.

Some of your terrestrials will go dormant no matter what else you do if days gets hot enough. This would vary with how the plant feels at that time so nobody can give a temperature at which this happens. There are winter-growing bulbous plants native to the chaparral surrounding your area. They go dormant in spring based on day temperatures, not so much water availability.

As to your plants, it would not take long to look them or their ancestors up in IOSPE and find out whether they are cool, intermediate or warm growers.

Your Pecteilis radiata should tolerate any amount of Southern California heat as long as it is wet. Recall it is a bog plant. In another recent thread I mentioned they easily tolerate Phoenix summers outside growing in pumice and standing in water.

Rose, the Zygopetalum would have been the first plant I brought inside. They don't like heat at all. It might take days to weeks for damage to show.

Originally Posted by Roberta

Everything that I grow outside, stays outside... (I'm not rushing 1000+ plants into the house when Mother Nature throws a curveball.) I have been watering more but that's it. Real world conditions, a range of everything from high-medium elevation Pleurothallids to L. anceps and Cyms. It hit just shy of 100 deg F (38 deg C) yesterday with 11% humidity. It was windy part of the time (good air movement but desiccating) , did cool off overnight. Today it hit 97 deg F (36 deg C), humidity got all the way up to about 15% . So, weather more suited to cactus than to orchids. No fatalities (some flowers wilted though but most of those were getting to the end anyway). Orchids are TOUGH ... short term temperatures outside of their "normal" can be tolerated just fine as long as they aren't getting blasted by direct sun (leaf temperatures much higher than ambient temps) or below freezing (which damages tissues) Stop stressing, guys... You have seen the range of what I grow outside. This isn't their first encounter with extremes.

Once again I appreciate the wealth of wisdom. As a novice there is a learning curve to navigate of course lol

I would like some suggestions about making my orchids flourish. It seems that Spring is a perfect time to have all my plants outside. I had them with 30% shade cloth doubled over. There were no burns, except several small black spots on my large Angracum. I don't know whether this was because I had it close to the wall, where sunlight may have crept in, or reflected off the wall. I got 70% thinking it's a catchall, for those which need some degree of shade

Considering your advice, Is it safe to experiment in the current climate with putting out lower shade plants in the sun, since the sun is not so intense? Could I maybe use a light meter app in the Spring sunlight, and compare it to requirements? I mean could a plant that needs shade in the Summer not need it in the Spring? This is a big question for me!!!

Would it be very helpful to have various shade cloths set up? I suppose it would not be much trouble or expense to set up small 'shade houses' (if that's the correct term) I am a bit surprised though, that I am unable to find such an item pre-made. Our backyard has pretty much no shade to take advantage of naturally.

Is there anyone that sells something like what I'm imagining, maybe a term for it besides shadehouse I could search? I mean something like those small portable greenhouses, not walk in, with shade cloth instead of plastic.. Something small you could secure to a surface.

Is it possible that the 30% doubled over is fine for Spring, but then the 70% would become necessary in Summer? Instead of one catchall, are there maybe three, like maybe 70% and 50% and 30%, and then full sun of course?

Sorry if it seems I'm not responding to your clarifications directly. I am absorbing them, while I still have basic questions!

[Roberta]

Don't overthink this... Some shade to take the edge off the direct sun is needed for essentially all your orchids - especially as we get to summer, but some even now when the sun is not so fierce... orchids hate sudden change, and the spring equinox is when the sun suddenly clears barriers. (I have toasted more leaves at this time of year than any other) You can gradually more the more sun-tolerant ones to less shade, but I can't think of many - or even any - orchids that really are happy with no shading at all. (I tried it with Cymbidiums when I first moved to my house, they didn't burn but were yellow and looked stressed... much better with light - 40% - shade cloth) In fact, when you see "full sun" on a tag, put into context. I had a plant (don't remember which one) that I got from Andy's Orchids and the tag said "F/S" ... I gave it full sun and burned a leaf. After a visit to the nursery, I observed that there is no place where there is full sun all day... lots of trees. The middle of my yard doesn't have them, so in mid-summer the sun is intense all day. Duration, as well as intensity, is a factor. So just build a basic shade structure, put everything under it. Some areas likely will get more shade due to trees, walls, house, etc and that's fine - put the ones that need less light there. If you don't have that, add another layer over part of it for those plants that really need less light.

IF plants have been in the house, even the high-light ones need to be acclimated gradually to higher light - move them from shadier to less shady areas over a period of a couple of weeks. Just like with temperature, an orchid can acclimate, but needs some time to do it.

---------- Post added at 09:27 AM ---------- Previous post was at 08:09 AM ----------

Another thought on the subject of shade vs full sun... even those orchids that need high light, typically don't get blasting sun all day in nature - where orchids live, it tends to rain. And that means cloud cover for at least part of the day. Especially in summer. A big difference between where most orchids grow - monsoonal climate with summer rain and winter sun - and southern California where we have a Mediterranean climate with summer sun, dry, any rain is in the winter (and not a lot of it). A friend of mine, living in similar climate down the coast, a better outdoor grower than I will ever be, sums it up well ... Coastal southern California is a great place to grow orchids outdoors, just add water and subtract sunlight.

[HiOrcDen]

Originally Posted by Roberta

Don't overthink this... Some shade to take the edge off the direct sun is needed for essentially all your orchids - especially as we get to summer, but some even now when the sun is not so fierce... orchids hate sudden change, and the spring equinox is when the sun suddenly clears barriers. (I have toasted more leaves at this time of year than any other) You can gradually more the more sun-tolerant ones to less shade, but I can't think of many - or even any - orchids that really are happy with no shading at all. (I tried it with Cymbidiums when I first moved to my house, they didn't burn but were yellow and looked stressed... much better with light - 40% - shade cloth) In fact, when you see "full sun" on a tag, put into context. I had a plant (don't remember which one) that I got from Andy's Orchids and the tag said "F/S" ... I gave it full sun and burned a leaf. After a visit to the nursery, I observed that there is no place where there is full sun all day... lots of trees. The middle of my yard doesn't have them, so in mid-summer the sun is intense all day. Duration, as well as intensity, is a factor. So just build a basic shade structure, put everything under it. Some areas likely will get more shade due to trees, walls, house, etc and that's fine - put the ones that need less light there. If you don't have that, add another layer over part of it for those plants that really need less light.

IF plants have been in the house, even the high-light ones need to be acclimated gradually to higher light - move them from shadier to less shady areas over a period of a couple of weeks. Just like with temperature, an orchid can acclimate, but needs some time to do it.

---------- Post added at 09:27 AM ---------- Previous post was at 08:09 AM ----------

Another thought on the subject of shade vs full sun... even those orchids that need high light, typically don't get blasting sun all day in nature - where orchids live, it tends to rain. And that means cloud cover for at least part of the day. Especially in summer. A big difference between where most orchids grow - monsoonal climate with summer rain and winter sun - and southern California where we have a Mediterranean climate with summer sun, dry, any rain is in the winter (and not a lot of it). A friend of mine, living in similar climate down the coast, a better outdoor grower than I will ever be, sums it up well ... Coastal southern California is a great place to grow orchids outdoors, just add water and subtract sunlight.

Thank you for this!

Earlier you mentioned aggressive watering. Can this mean not allowing to dry? Not that I want tor try it yet, but is this okay with wood chips? I know with bonsai when you have a quick drying inorganic mix you can water very aggressively, and it is even suggested you can use an inordinate amount of fertilizer. I know they prolly don't work the same. Just curious what aggressive watering means with orchids, especially if you can do so with organic mix. Of course I'n not going to try it just yet just curious how it works.

Thank you again.... In order not to overthink, since you have suggested shade cloths, how many different levels do you use? I understand with orchids it's basically 30-70%? How many and which levels do you employ? I hope this is a simple, and not simplistic question!

[Roberta]

Going backwards... I use 60% over everything except the Cyms and L. anceps where I use 40%. (See my website for pix) . I have used 70% for Paphs in one area but they just weren't doing that well, I moved them into an area with 60% but not all-day sun and they are doing better. So I'm not using the 70% anywhere at the moment. In the areas with 60% (most of my space) , there are other factors affecting the amount of light intensity and duration, so I have shadier spots and sunnier spots to play with. Those I just observe (and at different times of year) to fine-tune.

When it is really hot (as it was yesterday and the day before) just water the heck out of everything - you'll get evaporative cooling. In general, when you water do it thoroughly so water runs out of the pot - that flushes out fertilizer- and hard water- salts buildup and also pulls air into the root zone.(Most of your orchids are epiphytes, and roots need air... terrestrials just want to be damp/wet when growing) How often, and how damp or dry you want to keep things can be tweaked by choice of medium. I have a big collection. Everything in an area gets watered the same (automatic overhead sprinklers), but the effect is different dependent on medium. For instance, in my high-sun area, the Laelia anceps and such want to dry out quickly. The Cymbidiums want to stay damp (but both want high light). So... the ones that need to dry out fast are mounted or in open baskets with coarse medium (or none) and hanging where they catch all the breezes. Dry in a couple of hours after watering. The Cymbidiums are in small bark - they stay damp. Bingo, same watering and both get what they want which is opposite.

[Dimples]

In San Diego (except for places like Point Loma where the marine layer burns off for a few hours at most each day) almost all plants will appreciate slightly more shade than the nursery tag or growing information suggests. I’ve had success growing “full sun” plants (not orchids) in locations where they get 100% sun in the morning and 100% deep shade from the house after 12-1pm. Potted terrestrial plants always do better with slightly more shade than what they’d want if they were planted in the ground.

The California environment is BRIGHT all year. Low outdoor humidity = less water droplets in the atmosphere to scatter/diffuse light = sun rays are direct and strong. Unless a plant is tucked well back under a structure or is blocked by a very, very dense thicket of plants it will receive a high amount of ambient light even if it is shaded for all or part of the day.

[estación seca]

Apologies for making assumptions, but you seem to be very young at heart and enthusiastic. That often leads to biting off more than you can chew.

Let's go even farther back. Start with things easy to grow in your circumstances with minimal technology. There are thousands of orchids like that. Learn what orchids look like growing through the year. Learn what new shoots look like, what they look like as they mature, what new roots look like. Learn what sunburn on leaves looks like.

Then you can move on to orchids with requirements somewhat outside your growing conditions. You will recognize any problems when they arise and, from having seen similar problems in other orchids, you'll know what to do.

We can't tell you what will grow for you because we don't live there. I've been all over southern California when I was growing up, but not to your house. You will eventually want to push the envelope and see what you can grow.

But first get good experience growing easier orchids.

[HiOrcDen]

Originally Posted by estación seca

Apologies for making assumptions, but you seem to be very young at heart and enthusiastic. That often leads to biting off more than you can chew.

Let's go even farther back. Start with things easy to grow in your circumstances with minimal technology. There are thousands of orchids like that. Learn what orchids look like growing through the year. Learn what new shoots look like, what they look like as they mature, what new roots look like. Learn what sunburn on leaves looks like.

Then you can move on to orchids with requirements somewhat outside your growing conditions. You will recognize any problems when they arise and, from having seen similar problems in other orchids, you'll know what to do.

We can't tell you what will grow for you because we don't live there. I've been all over southern California when I was growing up, but not to your house. You will eventually want to push the envelope and see what you can grow.

But first get good experience growing easier orchids.

Thank you for this. Luckily though I purchased whatever caught my eye, they all seem to be suitable for my yard. The only exception is that my biggest and one possessing a pretty high light requirement, has got several tiny burns while all the rest, ten or so, including some tiny ones with higher shade requirements, all are still in flawless condition, again, luckily. I'm curious why. The burn spots have stopped popping up though.

My main concern is the ones with very high humidity requirements, 80% or so. I'm thinking that's why one is potted in moss brimming over the pot. Could this be sufficient, maybe with a humidity tray too? Reading about one of my species, a mister was recommended. But again, there has been no decline so far with any of my orchids, again, luckily. There are inexpensive rechargeable misters, even evaporative coolers, which I imagine might benefit the collection? (as you mentioned a fan)