40 F. is the average temp? Minimum? Maximum?--Way too cold for most of the plants you list--which are mostly tropical. Still, the Saxifraga, Chlorophytum,Geranium and Olive should survive the ice age. Really though depends on what you mean by 40 F..

I wouldn't actually trust any of the above to 40F, though in a pinch the Saxifraga and Spathiphyllum might come through it okay, especially if you're very sparing with the water. (Even if the Saxifraga defoliates, it's probably still alive and will come back.) I don't know about the Olea one way or the other, having no personal experience with them.

I'd move everything else. In fact, if you can somehow go back in time and move the Aglaonema and Philodendron, like, three weeks ago, that would be good.*

For tropical plants in general, you usually don't want to go below about 60F/16C; there are exceptions, of course, but tropical means, you know, tropical.

-

*Some Aglaonemas have been selected by breeders for cold tolerance, and can handle very cold temperatures for brief periods without injury, but the genus in general is very sensitive to cold. Without knowing the particular variety you have, a certain amount of urgency seems called for.

what about an electric heater? i agree with the above those temps are very cold for tropical plants but some may come through it just fine. I mean it does snow in southern texas sometimes and some people have ficus trees growing in their yards and they do just fine. Are these extended temperatures of 40 or under? Id either get a heater or clear out the room:) goodluck!

To be fair, some of the plants, like the aglonema and aralia, have new growth and two of the geraniums have flower buds. Hmmm...from stress?

I will move them.

I should have mentioned that the room is not a constant 40 degrees, but that the temperature fluctuates between 65 and 40, and unfortunately, it is the best lit room in the house.

Are there cold tolerant plants? I know the saxifraga dies back in the summer when it gets to 90 degrees or so, and then slowly grows back in the fall.

Olive should be fine.
I have an olive outside that gets snow.

Josh

Sure there are cool tolerant plants but these are not usually the ones to be found in your average NYC indoor plant store--which tend to feature tropicals that can survive the heat of the average overheated NYC apartment in the winter. Here are a few that will thrive with winters that have a 60's to 40's range. Your posting mentions nothing about light conditions but assuming there's some decent sun I'd suggest (based on personal experience) the following--if you can buy them locally (there's always eBay):

Citrus (oranges, lemons, kumquats)
Podocarpus (mine have been growing outside for years now)
Olives
Cycas revoluta (Japanese sago palm)
Phoenix canariensis (Canary Island Date palm)
Pittosporum tobira
ivy (English or H. canariensis 'Algerian')
Temperate bamboos
Yucca (including the tropical houseplant one)
Beaucarnia (pony tail palm)
loquats (Eriobotra japonica)
cacti
Chamaerops humilis (Mediterranean fan palms)
Rhapis palms
Most succulents including jade plants, agaves, and aloes (just keep them DRY)
Araucaria (Norfolk Island pine)
Trachycarpus fortunei (windmill palms)
Fatsia japonica
Dicksonia antarctica (Tasmanian tree fern)
Livistona chinensis (Chinese fan palms)
Clivia
Camellias
gardenias
geraniums
bay laurel
Schefflera (umbrella tree)--At least the dwarf variety has survived winters regularly in my cold garage.

Good luck!:)

There's not a lot that would be happy down to 40F, though at one point in my life I was living on an unheated porch, in winter, in Iowa, which occasionally got down into the high 30s, and as a result I know that Yucca guatemalensis/elephantipes can go to 40F (though just barely). Also Pedilanthus tithymaloides and (if kept very dry) Sansevieria trifasciata. I've also seen a jade (Crassula ovata) survive being covered in snow, over a long period, though I don't recommend it.

Cryptanthus spp. (earth stars),
Tradescantia pallida (purple heart),
Tradescantia zebrina (wandering Jew),
Sempervivum spp. (hen and chicks),
Asparagus spp. (asparagus ferns),
Hedera helix and H. canariensis (English and Algerian ivies),
Synadenium grantii,
Plectranthus nummularius (Swedish ivy),
Tolmiea menziesii (piggyback plant),
Spathiphyllum spp. (peace lilies -- which are much tougher, temperature-wise, than they look),
Clivia miniata,
and Schlumbergera cvv. (Christmas/Easter/Thanksgiving cactus)
will all tolerate cold to some degree or another, though some of those will die back, partly or totally, if the cold is extreme or sudden, and I don't know that I'd trust them all to 40F, especially if I didn't have to. Some orchids and Hoyas can also get cold for brief periods without damage, though I don't know that any of these should be kept cold for a whole winter, and it's only some of them, not all of them.

Wow Mr-subjunctive and Dave,

A big thanks from me too...! Alot more than I ever imagined..very imformative!

Mike..:-)

Hi there,
I'm in zone 9B, that means we don't freeze every year. I grow all types of geraniums outside, they should be fine at 40. The olive is definately ok. The Ficus won't like it but should be alright, I had one outside for 10 years without losing it. The rest I'd move into the warm part of the house.
Dee

Geranium =/= Pelargonium. Many Geraniums are fairly cold-tolerant; Pelargoniums not so much.

Mark, please explain what you mean...
Geranium =/= Pelargonium.

If IL temps didn't drop below 40F degrees, my tropicals would be outside year round..
'Except African Violets, Plumeria and succulents...succulents are included only if there was continuous rain.' Toni

The genus Geranium and the genus Pelargonium are not the same thing. The two words are not interchangeable.