Quick min/max for varieties?

[HiOrcDen]

So we are having a heat wave. This must seem like cheating lol, but I have been trying to get an idea of a kind of ‘absolute’ (as I know conditions vary) minimum and maximum safe temps for my plants, just to work with for simplicity, but I don’t feel like I’m getting reliably precise information. I hope I don’t seem lazy, and I know that several of you guys have been so nice this far! If folks could just toss up a quick number for min and max, that would be awesome! Please don’t bother with cut and paste, just put the min/max number in order, if anyone feels like it

Paph. barbatum var nigritum (barbatum x self)
Pyp. Mariposa 'Twins' (Pyp. papilio x Pyp. Kalihi)
Phrag. Millbrook (besseae 'Cow Palace' FCC/AOS x Nicolle Tower)
Den. Samurai (stratiotes x antennatum)
Onc. Jiaho Queen ' Jiaho ' GM/TOGA ( Mulattas x varicosa )
Angcm. Crestwood 'Tomorrow Star' GM/ 19th WOC , FCC/AOS ,CCE/AOS (Veitchii x sesquipedale)
Monn. Millennium Magic 'Witchcraft' FCC/AOS (Ctnchs. Midnight Jem x Morm. sinuata)
Brassia Orange Delight 'Hilo Sunrise'
Arthurara Sea Snake ‘Unforgettable’
Bulbophyllum Electrinum VAR Calvum, Miniature Orchid, Wood Mount
Platanthera Cilianus - Yellow Fringed Orchid
Stanhope Rachenbachiana
Ophrys Apifera
Ophrys Vermixia
Arhitectual Blue Orchid
Habenaria Radiata
‘Naked Man Orchid
(Sorry I have forgot scientific names you guys told me haha)

Also some tips on how to really figure this out for myself in the future would be great. I know to observe the plants and yard microclimates, and to research the habitat, but then there are hybrids. I was especially recommended here a few websites, for this especially by @Estación_Seca, to use for figuring such things out. One was I.O.P.S.E. I believe, will have to find the threads for another couple sites.
thanxthanxthanx:

[RoseSD]

I am also in SoCal and yes it was really hot today.
Other than cymbidium, zygo and epidendrum I brought all other orchids inside.

[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.

[TZ-Someplace]

I had a large diverse collection in a poorly designed greenhouse in New York that regularly hit 115F when summer days reached 95F. It had a lot of air flow from big powerful fans so the temps did not build up higher on the leaves. It got down under 50F on some cold winter nights. I was happy with 55F for extended periods in winter.

[RoseSD]

Estacion,
The fear of bringing mealybugs to my indoor orchids is greater than the fear of losing the health of that zygo....

[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.

[RoseSD]

Roberta is it true the hotter the temperature the more pests show.up? How do you manage pests on your orchids?

[Roberta]

I really don't have much of a pest problem. Probably because they're outside - so there is excellent air movement. And I suspect, enough other garden plants around that they have other places to go. While bugs are going to be more active in warmer weather (they are cold-blooded animals so they need some external heat) I don't think it is proportional. Also, plants flower in warmer weather in general, so that gives them something to eat ( not necessarily the orchids, plenty of other flowers) If you have good air movement, pretty much problem solved. The great outdoors has plenty of air exchange.

[RoseSD]

There is definitely a correlation of temperature rise and mealybugs in my zygo and cymbidium. The new shoots on My rose bush is literally covered with aphids daily so I fear they invited mealybugs to my orchids.😂

[Roberta]

Hmmm... never had much issue with mealybugs except on Phals and Paphs. For the rosebushes, maybe give them a handful of Bayer's rose food/systemic. I haven't had much issue with them, but I have used it occasionally (also goes after mildew which is a bigger problem where I live) . For the orchids, a systemic pesticide like Bayer's Advanced (or whatever they call it with the new formulation) may help. The only Cyms I have had issue with (scale being the main one not mealies) has been with less-than-healthy plants, there's a vicious circle between poor health and sucking insects which make poorer health. Healthy plants seem to be more resistant. For the Cyms, do clean up the remains of old leaves - those dry sheaths are hiding places for scale and such. Whitefly can be an issue for Cyms and other soft-leaved plants such as Lycastes and Stanhopeas (most noticeable on the undersides). But those are pretty easy to knock down with soapy water.

---------- Post added at 05:00 PM ---------- Previous post was at 04:48 PM ----------

With regard to min/max on Catasetinae, nights are now warm enough at my house to move them outside... As they get to the point where they are ready for heavy watering, out they go. (Only a few so far but a bunch that are getting really close) I can almost hear they saying "Ahhhh" and starting to accelerate their growth. Minimum for them is around 55 deg F (13 de C) or maybe just a bit cooler, I don't think that there's a max for them - with a bit of shade so that they don't burn, they like heat but not direct sun.

The Ophrys are no issue at all, they should be dormant this time or year or getting to be, won't wake up until things cool down in October or thereabouts. White pots helps keep temperature down inside the pots,