Methods to lower temps for Phal blooming?
 

I know that along with proper long term care and making sure they have enough energy after their last blooming period, a major part of getting a Phal to rebloom is lowering the temperature to the low 60's F (mid teens C) at night. Unfortunately I don't have any outdoor areas available to me to take advantage of natural temperatures (ah, the joys of apartment dwelling) so what methods would you suggest for getting the right temperature dips? Most sources just list the ideal temperatures without how to get them, or assume you have a greenhouse.
From my own research I've seen that putting a plant directly under a cool air vent is a bad plan because the air is way too dry and severe. It's also not practical to cool my whole apartment to that level.
I've seen a video that has an interesting idea: They put a layer of ice cubes in a shallow tray, then place the orchid on a pedestal a few inches above it so that the ice cools the air around the plant. (Link here) I tried to do some research on that idea specifically, but my results were too cluttered with the brand "ice cube orchids" to find anything. The theory seems solid and looks like it would solve the 'dry moving air' problem. Has anyone tried it or have any tricks of their own?

Tell us your temps, max/min seasonally.

Outside? The mins can get below -15 F in the winter and max out over 100F in the summer. (-26C to 37C) Longer term winter temperatures average around 0-10 F (-17 to -12 C) and longer term summer temperatures are around 80-90 F (26 to 32 C). Fall and spring are also getting increasingly unpredictable with the shifting climate.
My main problem is that I don't have any outdoor space, even a balcony or patio. My indoor temperatures stay around 70 F all year (21C).

Outside in winter will kill them.
Is there a time of the year when temps get low to the 16°C at night?

My temps don't go as low as yours, but I just crack open a window in my small office room during November. That lowers the temp enough to stimulate spikes in most of my phals. I have some species phals in another room which doesn't get quite that cool, (fasciata, bastianii) and they bloom too, so I don't think the exact temperature is critical.

My mother have some Phals inside...some bloom while other never do.
I've advised her several times to put them outside around September/October but, as she never followed my advise, I couldn't test it.

Commercial growers do this to get their Phals to bloom for the major holidays. (The orchid that blooms a week before Mother's Day is worth a lot more than the one that blooms the week after) They typically provide heat by circulating warm water under the benches, so it is easy to run cool water for a week or two at the appropriate time. However, for the hobby grower who is happy with blooms whenever they happen, this is really not an issue. When I lived in a condo, I found that I could greatly increase the number of Phals that rebloomed by simply providing supplemental light from the cheapest fluorescents that I could find (just generic full-spectrum bulbs,not grow lights) on a timer 12 hours a day. As the weather cooled, the indoor night temperatures dropped a little, but I doubt very much that it made much of a difference.(I had the same night temperature drop the year before without the extra hours of light and not much happened) It was increasing the duration of light that did the trick. Now, I wasn't trying to time the flowers for Christmas or Mother's Day, etc. as a commercial grower would. But I did get flowers.

Are you trying to induce it to bloom at an unnatural time? Mine always bloom from mid-winter to early- spring. I've got mostly winter bloomers. The only bloom right now is a dendrobium hibiki.

I guess at the moment it's mostly a hypothetical question, based on a gap I've noticed in the material I've found. I've been doing research on Phals because am planning on picking up one or two at the local orchid growers sale this weekend. (Only one or two I say now, but who knows how many I'll end up with). If they're grown in accordance with the seasons, they likely won't be in bloom when I get them and I'm thinking towards how I'll handle blooming them in the future.
That being said....I can't believe I was so wrapped up in my own head that I didn't think to just open a window. :dumb: Thanks fishmom.
Also thanks Roberta for the grow light idea! If I'm getting stuck I'll definitely try that.

They will probably be in bloom at the show... the commercial growers dink with light and temperature to get Phals to bloom at any season. (They can't get much money for an unbloomed Phal, so you won't see them at shows unless there's a "bargain table") Under your care, they will revert to a more normal bloom cycle, but there is plenty of variability there. So just be patient. Once they go out of bloom, continue the good culture, keep them healthy, and they will re-bloom. (Whenever they feel like it)

I don't even think that opening a window is necessary. Contrary to the common idea, Phal blooming is not triggered by a drop in night temperatures, but a general cooling down of both day and night temperatures. This will naturally happen when we move into fall, and unless your house is an air-tight, completely climate controlled box with no temperature variation. In my apartment it's about 26/23C (day/night) in the summer, and I start to see spikes about 4-6 weeks after the averages have gone down to or below 23/20C for 2-3 consecutive weeks,

This somewhat old AOS article explains very well how commercial growers manipulate blooming. This represents the ideal conditions (for a homogenous, double spiked crop), so temperatures given should not be taken as the rule. Phals will bloom under far less strict conditions in our homes. http://www.aos.org/AOS/media/Content...halsPart_3.pdf

Good light is also important as mentioned before, but (lack of) light is more of a limiting factor and not a blooming trigger.

Where ever you got that temperature advice (from Miss Orchid Girl's video?), it is yet another example of folks teaching more than they know.

A phalaenopsis does not have to go into the 60's at night to bloom. In fact, even a "nighttime cool down" is technically incorrect. The trigger for reliable spike initiation, proven by Dr. Yin-Tung Wang while at Texas A&M, is a 10-15F reduction in average growing temperature for ten days to two weeks.

That means, for example, that if your apartment is 75 day and night, and you start lowering the nighttime temp to 60, you're achieving an average reduction of only 75-60/2=7.5 degrees, and you may- or may not get the desired result.

I have a friend in Central America who grows phalaenopsis is 100-degree plus conditions. He forces them by lowering the temperature into the 80's.

In your case, the temperature is low enough, now you gotta spike the temperature up to about 29.4℃ - 32.2℃ (85℉ - 90℉) for a few weeks. It is not necessary to go any higher than 32.2℃ (90℉). Those temperatures are very uncomfortable for a person to be in, but the plants love it. Just make sure the humidity doesn't drop drastically. Warm and humid, Phals love. Warm and dry, they can still do ok, but they don't like it too much. Commercial Phal greenhouses feel like saunas without the steam. If this is how your growing area is, you're on the right track.

I'll see what I can reasonably do, and what some of the local growers at this weekend's show say. I'm afraid I'm not quite that invested in all this, and I wouldn't want to saddle my roommates with an outrageous electricity bill and weeks of miserable temperatures over a plant I don't even own yet. Again, I was mostly asking about how to achieve a localized temperature without having access to outside space or a greenhouse.

I think this is becoming 'way too complicated. Many members of this forum manage to grow and bloom Phalaenopsis in their living areas quite successfully without going to a lot of trouble and expense. The plants will perform with just the basic conditions being met. Can an expert optimize conditions to get better results? Of course. But a hobbyist who is not trying to produce thousands of blooming plants for sale at a particular time does not have to work that hard.

I don't know how warm it is outdoors at your apartment, but it is achievable by placing your plant in the warmest spot with some shade for a few weeks. I mean, since it's summer, leaving the plant outdoors is easy. You just gotta prep for fall and winter to have the Phals indoors.

The only expense needed is a thermometer or two.

Your electricity bill depends on how cool you want to keep yourselves in the apartment. Just make sure the ac isn't set to below 18.3℃ (65℉).

Normally, I don't really encourage artificially inducing blooms on Phals, but if you were truly interested in doing such a thing, the easiest way to do it is how I mentioned it. If you were planning to do this year round at your own whim, then that would take a lot more effort than it is worth.

Keeping them on a windowsill has been enough to get most of my Phals to rebloom. The glass doesn’t provide enough insulation to prevent a winter temperature drop. Bright indirect light also helps. One of my Phals kept on a darker windowsill only produced 3 flowers, but moving it to a brighter location resulted in 8+ flowers this year.

As someone who struggles to keep phals alive, but managed to get several to spike and bloom this year, I can say that it was not a complicated process for me. Fertilize weakly, weekly, got a humidifier for the winter, and light definitely plays a role as all the blooming phals were located in essentially the same spot by a southern exposure. Indoor temps were 65-70 F but the phals would have preferred higher. I didn't do anything in terms of trying to trigger spiking.

I have one that just finished blooming that went into spike in April or May, and I have one where the blooms have just opened. It spiked in June with no cold exposure. Then I have my beloved NOID that I consider equestris based on its behavior, that blooms pretty much continuously (the blooms are small but charming).

For those trying to force blooming in the home, I did it once by accident and now I am trying to figure out if I can do it on purpose to keep fresh flowers on my wife's desk. By accident, forced blooming a few years ago by putting an orchid under the 24 hour lights on a heating pad with zinnias I was starting. When the zinnias where ready for the yard, I just stuck the plant in a window with extra moisture because it was drafty from the ac. It spiked pretty quickly after that, so I figure that the difference between the heating pad and the evaporative cooling in a 72 to 76 environment was plenty to convince the plant to flower, so now I have a few plants on the window, and several growing on a heating pad. In a month I will try moving it from the heating pad to the window and keep the clay pot damp and evaporating and see if it spikes. If it works I will label my pots by months 😁

Heat, good; 24-hour lighting, bad.

There are different - and essential - processes that go on in a plant in daylight and at night. By eliminating the latter, you actually weakened the plants.

A little tip: after repotting a plant, place it on the heating mat for a few weeks to accelerate root growth.

Good point, I do know better now. It just happened to be the only lighting I had going in the fall stuck on the shelf with the seedlings.

I know that the nurseries know how to do it. They sell phals as "cut flowers" and don't care if they live beyond the bloom. Do they ship in a refrigerated container? I don't know. And when you get the phal which is unnaturally induced to bloom at an off time, yes, you might get a year it does not bloom because the annual rhythm is off. I have found (as far as natural rhythm, as Ray says, that putting them where they get real weather and sun, even part year, really makes them stronger).

Hi Misterguy, as you can tell, when you start to ask these types of questions, very often you can get all sorts of different answers! But Ray and King are right in that there is an average temperature difference needed and many phals like to grow quite warm (for our taste). I am also growing my phals and other orchids in an apartment here in the Midwest. For my phals, I provide some artificial light year round (shady window doesn't let much through), fertilize regularly, and then come November- February I usually get spikes and blooms just by having them within 2 feet of the windowsill. Granted, my usual summer temps are in the 75-80F range (under lights) during the day and then down to about 70F at night, but in winter, they dip down to 65-68F night with my provided space heater (otherwise it gets too cold). All of my healthy phals then tend to spike year after year without fail. If you are planning to get spikes naturally or artificially, I think that it is essential that you first focus on the year-round health of the plants, and then you will be rewarded with the spikes/blooms that come as a result. :D

Well, I got my first Phal! Just for coming everyone got a free one, and I swapped with someone else because I loved the yellow tint and they preferred mine's purple spots. I like that this one has an ID!
Should I fertilize while it's flowering or not?

You can fertilize while it's flowering. Many people have different fertilizing regimes such as "weakly, weekly" or a fertilizing followed by water for the next 2 or so waterings. I think the biggest thing to keep in mind is that fertilizing should be heaviest during periods of active growth (usually Spring/Summer) and then significantly slowed during slower growth periods. As a beginner, I suggest reading this sticky: The Phal abuse ends here.

I'm trapped inside, so I figured I'd follow up. My attempts to build a swamp cooler failed horribly. You know what worked perfectly by accident? All three of the plants that I brought in from the backyard a few weeks ago have spikes going. So I guess in NC, the trick is shade and then air conditioning.

Or maybe it's just time for them to bloom. Unless you can run a controlled experiment (pretty impossible for the hobbyist) by giving some plants one treatment and other very similar or identical plants a different treatment and getting different results you have no way of knowing whether something you did made a difference, or whether it would have happened anyway, especially with a sample of only a year or two on a very few plants. Or putting it in more scientific terms, correlation does not necessarily imply causation.

In this context, it's both the observed and predicted behavior based on temperature. I have plenty of other plants that didn't go outside that didn't initiate spiking yet and also haven't experienced any temperature changes.