Finding the correct temperature for growing your orchid is essential for it to bloom. You can water, apply humidity, provide light, and fertilize correctly, but if there’s not a temperature fluctuation at night, most orchids will refuse to bloom.
Does temperature influence orchid growth? All orchids need at least a 10º to 15ºF degree temperature drop at night to bloom. This cooling off period at night removes the excess heat from their leaves. This aids in performing adequate gas exchange, since most orchids perform their main “breathing” process at night.
During winter, do you run the heater during day and night, too?
If you grow your orchid in the same environment year-round, with no variation of temperature, the first signs you’ll see are of heat stress. Heat stress occurs when the orchid shuts down its gas exchange (stomata) pores to preserve humidity. It does this because it’s too hot, and will lose humidity if stomata are opened.
Turn off the heater at night. Besides saving in energy costs, your orchids will appreciate the drop in temperature.
Orchids have temperature preferences, too. Not all orchids like to live in the same climate or habitat. When you bring an orchid indoors, you’ll need to recreate their primordial habitat within your home. Imagine if you place a cool-temperature orchid next to a warm-one and give both the same treatment.
One, or both, will have a hard time growing. That’s why it’s fundamental to understand the different types of orchids and how they react to each temperature.
Nighttime temperatures that are too low will produce blackened tips on the leaves. Flowers will wilt.
Tip: Don’t mistake these with the normal aging of leaves, which occur naturally. When leaves die off, the start to blacken at the tips. But temperatures that are out of control will also cause blackened leaf tips.
There are three distinct categories for temperatures: cool, intermediate, and warm-growing orchids.
Cool orchids tolerate temperature of 50ºF (10ºC) during winter. During the summer, the maximum should be 75ºF (24ºF).
Intermediate orchids prefer 55º to 86ºF (13º to 30º C).
Warm growing orchids range from 64º to 90º F (18º to 32º C.)
Is temperature the only difference?
One misconception is that the orchids that thrive in these three distinct temperature categories are naturally from locations that have the same temperature. Even though this is an understandable mistake, it’s not the temperature that influences as much as the elevation.
Cool-growing Orchids
Cool-growing orchids are found mostly in higher elevations. Elevation doesn’t necessarily mean in feet (or meters), either. Sometimes, you can observe cooler growing orchids higher up on trees, and not lower. But mostly, they grow in higher elevations compared to the other two categories.
These orchids include:
Cymbidium,
Coelogyne,
and
Odontoglossom.
Intermediate-growing Orchids
In nature, the intermediate-temperature orchids can be found in an altitude that ranges from 1,000 to 3,000 feet. Of course, this does depend on how far away from the equator you are, too. The majority of the orchids that can be grown indoors come from the intermediate category.
Aerangis
Cattleyas
Cymbidium
Epidendrum
Maxillaria
Paphiopedilum.
Warm-growing orchids
The last group, the warm-temperature orchids, coincide with lower elevation orchids. They are naturally gown closer to the tropics and the equator. Therefore, they thrive on high-light, direct sun, high humidity and…are extremely difficult to grow indoors. If you live in southern Florida or the Gulf States, you’ll have more success growing these outside.
Indoors, these warm-growing orchids are extremely difficult, near to impossible to grow, unless you want mold on your walls and indoor light system that recreates our sun.
The one exception is the most famous orchid, the Phalaenopsis.
It is a higher-temperature orchid, not to mistake it with a higher light orchid. These are two separate categories.
Vandas are also included in this category.
What if an orchid gets exposed to higher or lower temperatures?
This open-ended question has a lot of what-ifs to answer. Usually, if the orchid is exposed to a colder temperature, like from the greenhouse to your home in the back seat of a car,bud blast an occur. (Read this article for more information on bud blast.) The leaves can wrinkle, curling up on themselves. These are reversible situations and can be avoided in the future.
If you purchase an intermediate-growing orchid, and constantly kept it a sub-par temperature, mold will start to grow on the crown and leaves.
But if the orchid is exposed to year long exposure of temperatures that are sub-par, they probably won’t blossom. Smaller pseudobulbs will grow compared to last years. Leaves can dry up and fall off prematurely. Flowers wilt. The growing period will take longer, and new roots and flower spikes will take forever to appear.
Insufficient lighting is the number one reason orchids won’t bloom, but the second is too low of temperatures.
If you don’t have one already, a thermometer with a humidity gauge is essential for orchid care. They are rather cheap, like the one I have (Affiliate Link)
cost around 12 US$.
| Minimum At Night | Maximum During Day | Orchid Genera (examples) | |
| Cool | 50º F (10º C) | 75º F (24º F) | Cymbidium Coelogyne Odontoglossom |
| Intermediate | 55º F (13º C) | 86º F (30º C) | Aerangis Cattleyas Cymbidium Epidendrum Maxillaria Paphiopedilum |
Warm | 64º F (18º C) | 90º F (32º C) | Angraecum Dendrobium Phalaenopsis Vanda |
If you observe the graph above, you might be thinking, “But my Cattleyas grow in 100ºF weather during summer.” When literature refers to orchid temperature, they always record the highs and lows as observed during the winter months.
Summer is not accounted for.
Why is this? During summer months, temperatures will naturally be higher, but won’t hinder growth if you’re a bit outside the natural preference zone. As long as you don’t overheat or provide too much sunlight, causing sun damage, there will not be much to notice.
It’s during winter that the temperature has more direct effect on the growth of an orchid, and can hinder blooming. This isn’t to say that if you have a cool-growing orchid and force it to grow in hotter conditions, it probably won’t blossom.
Temperature Fluctuations Night/Day and Seasonal
Not only do orchids need a fluctuation in temperature during the days/nights, they also need a distinction between seasons. You’ll see this more when you purchase winter blooming versus summer blooming orchids.
Seasonal distinctions are extremely important to orchids, as other houseplants, too. During winter, there will be a shortage of natural nutrient supply, so you’ll need to water less.
Fertilize less, too.
The days will be shorter and darker, so you can turn down your artificial lights to around 12-14 hours a day, instead of 14-16 hours.
And…
There will be less pollinators in the environment to justify blooming.
This is crucial.
A flower only blooms to propagate its species, and if they attract a certain type of pollinator, that only comes in winter or summer, why waste the energy to bloom out of those seasons?This is why each orchid species has a different blooming period: some bloom in summer, other spring, others winter… The upside is that you can have orchids in bloom year-round in your house if you choose the right ones to make your collection. Phalaenopsis bloom year round.
Think back to the natural habitat of the orchid. There aren’t such distinct summer/winter changes, in terms of temperature. Most subtropical and tropical orchids live in a constant temperature year-round, only fluctuating during the day and night.
During the day, no matter summer or winter, the orchid needs to be in a warm place. Indoor orchids do well because temperature fluctuate less and are easier to control.
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How to maintain temperatures
Let’s say you went to an orchid greenhouse and came home with a Cattleya and a Phalaenopsis. Knowing that these are in two separate groups (according to temperature), you’ll know that placing them side by side on the same shelf won’t be the best solution.
To have more success at growing orchids, you can set them up depending on their temperatures, each in a different corner of your house. Use the windows and natural sunlight, and group orchids together by their temperatures.
A good suggestion is keeping the cooler orchid in the bedroom, warmer orchids in the kitchen, and intermediate orchids in the living room. Of course, this is a wild suggestion, but you get the idea. Grouping them together provides humidity, but also is easier to control variant temperatures and lighting.
This way it is easiest to display your orchids without having a proper greenhouse, orchid room, or making your house transform into a live jungle.
Too much information to memorize?
Download this 1-page PDF reference of what you learned on this article and other important information about artificial lights, which you can read here.
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Now that you know how to care for your orchids according to their temperatures, drop us a comment below on anything that wasn’t touched upon in the article or if you have a question or comment.
If anything, drop us a note below to say if you enjoyed the article and ways we could better help you care for your orchid.
Happy Cultivating!
I am a beginner orchid grower (Phalaenopsis) and my orchids are on the screened porch in South Carolina. The temperatures are great now but when it gets above 95 degrees F should I take them inside? We also have high humidity here when it gets that hot. Thank you
Hi Pauline,
Phalaenopsis grow better at 90F so the 5 F above wouldn’t be such a dramatic change. The temperature ranges are more like “ideal conditions” but some growers can extend those above or below and still have perfect blooms. My main concern would be the drop at night. How cool would it get? Is there a drop at night or does it stay warm at night too? With the humidity that high it might be hard. Try a few out on the porch (the ones you’re less attached to) and experiment. If they do well, take a few more out. I know its not the most technical answer, but it works. 🙂
-Amanda
I saved 6 orchid plants from a lady that was moving away….I do not know what types they are..she was difficult to understand because she was from Brazil….now I have them, only one was in full bloom and the others have very healthy leaves in large and small pots…some with drainage and some with not…I want to keep them alive and need to know how to handle this variety of plants… I have the large ones in a screened in porch( I live in central Florida), and the smaller ones out side under my car port…they seem to be healthy but no blooms except the one, which has now dropped the blooms…dont know if they were on the way out or the change did it. They get morning East sun and no sun the rest of the day.
I spray them lightly with room temp bottled water….around the bottom part that are in the dirt, which looks like wood chips, roots, some stones…..They look very healthy, but what do I know of the hidden secrets of these beautiful plants….help me keep them happy and blooming…thank you for any response you can give me……Rose Marie
Hi Rose Marie-
I just moved to Central Florida-Lake Panasofkee a year ago.
I restarted my orchid collection when I got here. No matter how I tried, I did not have success in Colorado! Too dry!
I have my orchids in a similar place as youl It is on the front covered patio with east exposure in the morning. I’ve only lost one orchid so far. They seem to love the location. My comment for you is to be patient. Just because they are not blooming does not mean they are sick or dying. Each different orchid will bloom at different times.
#1 What I do here is every 7-10 days I bring them all in and soak them in my kitchen sink (thoroughly cleaned before doing this!) for up to one hour. Take them out of the decorative pot if in one and just put the drainage pot in the water. Don’t let the root ball get wet! I typically let the water get within about an inch to the top of the pot only. On the advice of my orchid guru friend I add only a small pinch of Schultz Orchid Food (Amazon) to the water in the sink before adding the orchids. Schedule and soaking time depends on how hot it gets outside. When we were having 98 degrees here a few weeks ago I soaked for an hour.
#2-Then just let the water out of the sink and let the plants drain for at least 30 minutes to an hour. Orchids do not like wet feet! Then put them back where they were. It sounds like your planting medium is correct. I’m told by my orchid guru friend only to transplant to larger containers after blooming and if they look like they are REALLY cramped or growing out of the pot. They don’t mind small spaces. I’m up to 5″ drainage containers. I found really nice ones on Amazon. Zirka in a pack of 5. They have larger sizes too. I find it difficult to find these supplies locally. Now..after you see a stalk coming out you can increase the fertilizer a bit with the watering until they are fully in bloom. (This is the part that I am not an expert at so go slowly with the fertilizer. Hopefully Amanda will weigh on on this part.
Good luck!
Hi Amanda. I have been growing orchids for about 2.5 years now, I’ve never been good at growing plants and keeping them alive so this has been and still is a learning experience. About 3 years ago I moved back in with my parents to take care of them as they were both about to turn 80 and both had dementia and dad had just been diagnosed with terminal prostate cancer. Sad to say Dad is no longer with us. So now it’s just mum and I and dementia is a evil disease that had taken most of the joy of living away from my mum so I do whatever I can to put a smile on my mum’s face and orchids and African violets are 2 species of plants that I know mum has always loved so I have been trying my best to keep them alive after the flowers gone and to get them to bloom again. I have had some mixed success with both types of plants and only found your article as I was looking for information on leafs turning yellow and falling off and I just wanted to let you know that I have learnt more in the last hour from your article than I have in the last 2.5 years and apart from a few occasions where I could see you have accidentally put a “F” (for Fahrenheit) instead of a “C” (for Celsius) (sorry where I live we use the metric system). l found your article to be absolutely full of relevant information for newbies (like myself) RE: How to take care of orchids. Unlike a lot of other articles that have lots of words and lots of ads but tell you nothing. I have spent a substantial amount of time reading and talking to so called experts and none of them have explained or even mentioned the importance of temperature or the signs that indicate over watering. So I would like to say “Thankyou for your article” you may have just saved the lives of a dozen or so orchids. I would like to ask you your thoughts on what I believe is peat moss the growers around here (Gold Coast Queensland Australia, subtropical climate) like to grow there orchids in and then transfer to a bigger pot and cramming a lot more peat moss in just before they sell them to big chain outlets like Coles and Bunnings as it’s been my experience that it’s very difficult to give orchids the correct amount of water as peat moss seems to keep the orchids roots to wet and the roots in the pot rot from being to wet while the air roots shrivel up and die from being to dry and the result for me has lead me to repotting them ASAP. I use Osmocote orchid potting mix I get from the hardware store and even though it seems to be better than just peat moss I still believe that the orchid mix I’m using is average at best as it seems to have to much fine mulch in it (almost like soil) and it doesn’t drain well enough and once again the roots in the pot rot, so please if you could give us newbies some sage advice on the best medium to grow our orchids in and the best time to re-pot them and the best fertilisers to use and how often to use it, that would be a big help. Again thank you for your article, Allan PS: Like a lot of newbies all my orchids are Phalaenopsis, which I am told are the easiest to grow and to that I call them Moth orchids as that is easier for me to pronounce
Wish you listed sources!