Kelly I think the best guidelines would be the temperature tolerance table that David Liddle had compiled, SRQ has this up on their site.
My plant collection falls between intermediate to warm with a few hot growers. Generally the low for warm growers is best not to fall below 65F but intermediate growers are fine with the temps you mentioned. Can you separate the warm growers and move them to another spot? I do know some orchid growers who have used seedling heat mats to keep the root zone of warm growers at the desired temperature, this way they can keep them in the same grow space as the cool/intermediate growers.

Mike

Well, I am in a semi-tropical location and in the six years I've lived here, I have been able to move hoya's for two years. After that, they entwined the tree so thoroughly that I couldn't move them anywhere, no matter what the temp!

Cena, what's the coldest it ever got in your backyard? Just curious how low your temps got...it would be very interesting to see how cold your Hoyas got and survived. It would be so helpful for me as well... Thanks!

Thanks, Mike! I printed it out the list and highlighted what I have! Ended up turning on the old heat as well, as life has been too busy to figure out anything else!

Cena, I, too, would love to know what temps drop down to where you are!

Kelly

I accidentally left a pot of Hoya lacanosa cuttings outside for two days/nights when the night temperatures were just barley above freezing. The potting mix was pretty much dry and this is probably why I don't have a pot of mush but still I am very surprised that the cuttings survived.
Just thought I would share because this is not at all what I would have expected to happen to this species under those harsh conditions.

Mike

I had some of the hoyas down to 39 degrees but It nearly killed Coricia, my beautiful archiboldiana and few others. So I am not going to push too much this year. I think most hoyas will do ok as long as it dosen't go below 50.

Jan

I spoke too soon because that pot of lacanosa cuttings is very yellow now, just took it's time to show the damage.

Mike

Mike, I am sorry about your lacunosa. I hope it recover for you.

Jan

Thanks Jan. I have two other plants so it's not a big loss. This was a pot of cuttings that had seen better days, had been fighting mealies on the one for a while.

Mike

Interesting to see your guys concerning about cold temp!!!
We do not have snow, the climate is not cold at São Paulo, and we never loose plants due to cold temps, it is a little bit different at south of Brazil, where is colder than São Paulo, but we never move plants due to climate changes!!!!! THe summer is coming and temperatures get really high, we feel very bad, the sun is very hot, we are always sweting no matter how many showers we take during the hot days! But I think this is the perfect weather for hoyas!

I've had two bad freezes. There were three nights in January (08) that the chicken water froze a skim when it dropped to 29*. There are a lot of variables to temperature range how plants will handle them.

Then there is the fact I can't change this if I wanted to, without lot'sa ladder work (I'm not allowed on ladders).

We're getting a cold front tomorrow night and our lows are forecasted to be between 39ð to 43ð degrees for about 3 nights in a row. My Pubicalyx and Carnosa varieties have fared very well in these temps outside last year ...are there other hoyas than can take these temps like say...Serpens, Bella, Polyneura, Kerrii? Or are these too cold for them? I will bring them inside just to be on the safe side but was just curious if there are hoyas other than Carnosas and Pubicalyx's that can take upper 30's to 40's w/out any damage? Thanks!

My serpens I leave outside until it freezes, and then it only comes in for the freeze. Survived all last winter this way, and rewarded me in the spring with blooms for the first time.

So far this year, we've had quite a few nights in the high 30s low 40s, and the polyneura and bella have responded by adding lots of new growth since it cooled off. Also have my fungii outside with these temps as well. No damage so far.

But I want to add we don't stay at these temps, we go from a few nights at the low temps, then a few nights into the 50s or even 60s and so on.

That's interesting about serpens. I'm usually more concerned about moving warmth-loving plants away from the winter window ledge zone of doom, but maybe I should be thinking about moving serpens and its buddies to that spot. Granted, they'll still be only a few feet away from the space heater but they'd be a little cooler than the rest of the Hoyas.

I love that you guys are discussing what plants can handle temperatures outside your house and I'm thinking about what plants can handle temperatures inside my house. ^_^

Mitzicos, I don't envy you your summer. My legs got so cold they nearly snapped right off on my walk to work this morning, but I turn into such a surly slug in hot weather.

Thanks rennfl...that's very interesting and very good info. I think its great you're able to leave them outside until there's a freeze...I might just leave serpens and polyneura outside(but in my entryway) close to a wall, maybe it will trigger something to get it to bloom in Spring, even though its small I think its mature enough to bloom?

We are only suppose to be upper 30's for two nights and low 40's for one night...then it starts to creep back up to mid 50's...and our day time temps are expected to be sunny and in the upper 60's and 70's for the next week.

Please lmk if you have other hoyas that you keep outside in these temps...this is great info!

GG, I think what temps hoyas can handle inside and out is a great subject too and we can learn so much from each other experiences...can't find these type of great info in a book :o)

Thanks again!

puglvr - I'm up in the FL. panhandle, so we get a little colder than you through the winter. Although I'm on the coast, so it moderates the temps a little bit.

The other plants I left out for those colder days so far were my DS-70, which did get some damage (but still is blooming) and the obscura. The obsucua's older growth survived fine, but the two new leaves suffered cold damage. So they are coming in for tonight, and will stay inside now.

The other ones I mentioned before will only come in for a freeze, and then go right back out the next morning, as soon as it gets above freezing.

But as you mentioned, since the days warm up, it's not quite the same as northern growers, where the days don't warm up.

That's it, the other Hoyas I have are all inside already.

Pug, I totally agree. Every day I'm picking up scraps of information and sticking them behind my ear for the day when they'll be useful. Then, I find I have all these completely unearned instincts available to me when I'm puttering about. It's kind of like being a Reverend Mother from Dune: I have all these lives and experiences in my head besides my own meager supply. ^_~

I think when I get home I'm going to do some rearranging and shift variegated bella, longifolia, fungii, lacunosa, polyuneura, obovata, and pauciflora onto the window ledge.

publicalyx, bella, engleriana, serpens, globulosa, and all the carnosas are already in cool spots.

I think going forward, I'm going to prioritize cool loving Hoyas even more. They're my buddies.

Thanks Renn! I'm thinking of leaving my Kerrii outside under some palm trees...I think they should be able to handle mid 30's, no frost is predicted. This one hasn't bloomed yet and might help it to bloom in Spring?

GG, I hear you! I need to do a much better job compiling all these great information so when I need it I can find it,lol...I spend more time researching something I remember reading months ago :o)

I know about remembering info. I actually (am embarrassed to admit) have an excel spreadsheet detailing each plant I have. Details like when/where I got it, various synonyms, recommended growing conditions - things like that. And then I have a comment section where I will enter stuff like - survived 40F etc. Or 50F ok, 40F not. So next winter, I won't have to do the research all over again.

I started doing this when my orchid collection got to the point where I couldn't remember all of them, let alone what conditions they liked.

Don't be embarrassed, Renn! I keep several journals - one for plants acquired, one for weather,
and one for seed-starting and harvest (at the end of the season). The more notes the better!

As for Winter temps in my house - I keep my thermostat set at 64ðF, although I wouldn't mind it lower.
If the temps get much about 70ðF, I start to feel uncomfortable. 78ðF is right out.

At night, the temps drop into the 50ðF's in the Hoya room, and probably a bit cooler near the windows.
I also use a ceiling fan to keep the air moving (as Mike suggested in one of these Threads).

Humidity is always fairly low in the house, and even moreso when I've got a woodfire going.


Josh

I initially started my records system just b/c I was afraid of ordering the same plant twice, but it's become lovely, fat, and complex, and I'd be lost without it.

I totally hear you about Garden Web, though, Pug. A few months back I got fed up with banging my head against the wall searching for vaguely remembered threads that now appeared never to have existed. So, I started up an additional system for saving those links. It's neurotic and time-consuming, but I'm soooo relieved when it takes me 30s to find coffee as a pesticide or who here likes Al's Gritty Mix.