Phal bellina temperatures: don't wanna boil it!

[MateoinLosAngeles]

I have a Phal bellina x self seedling that is happily growing in S/H. The plant is growing next to other Phals on heat mats in a very small pot barely 3 inch above the mat. I have a sticky thermal tape that gives me an approx temperature reading.

I've observed that as December kicked in, this was reading too low for my liking. Reaching 60-65ºF at night, despite being on a heat mat. So I grabbed a smaller heat mat I had laying around and wrapped it around the pot like so:



Now, the problem is that I fear this mat might be too hot. The top of the pot where most of the roots are reads 85-100ºF. I inserted a household thermometer through one of the reservoir holes and the water read 95ºF.

I don't think this is very off from the temperatures in Borneo, but they feel a bit high. Here's an average monthly temperature in Kuching:



The heat mat is connected to a smart plug, so I can schedule it to be on and off and different times of day. The problem if I only turn it on at night is that the smaller heat mat heats the pot so much that it would lead to temperatures above 90ºF at night, whilst the plant would experience 75º-82ºF during the day. Making the plant be hotter at night sounds off to me.

The solution could be to time it so it's continually on except for the hottest times of day: between 10am and 4pm. But that would mean the plant would stay between 85ºF and 105ºF.

Am I gonna overheat this plant?!

[Dimples]

Have you tried putting a clear plastic or glass container over the top of the plant to trap the heat around it? This would be without the smaller mat. That may be enough to keep the single plant warmer than the others.

[Roberta]

THat's getting too warm, I think. A consideration with semi-hydro... it may be giving too much cooling to the roots (without the electric blanket) You may be better off with bark, and just the standard heat mat. Another thought, a small space heater in the area where you are growing the Phals might give just enough ambient heat (a whole lot cheaper than heating the whole house) to keep the Phals happy.

[PuiPuiMolcar]

This will probably sound absurd but have you try using christmas light? I think you can create ambient warmth by using the small chain of light encircling around the plant or in a dome with it. I've done this with my Owari Satsuma tree when it was too young to weather the winter chill. But that is a tree, I have never done it on orchid before, anyway take this information at your own risk.

[Arizona Jeanie]

Is the heat mat on a thermostat? You can set the temp you want, and don't need to turn it on and off.

[MateoinLosAngeles]

Originally Posted by Arizona Jeanie

Is the heat mat on a thermostat? You can set the temp you want, and don't need to turn it on and off.

No :/

[Lil Duck]

I think that it will be fine, I have a little Phal modesta that is growing in much of the same conditions as yours, roughly 82 (27) during the day and 60-61 (16) at night, and it is still growing fine. Would it appreciate and grow faster with warmer night temperatures? Sure yes but most orchids, Phals included appreciate a drop in nighttime temperatures and I would rather give it that drop in temps than fry the little orchid trying to keep the temps at what it is used to in nature (as well as saving money on the electrical bill!! ). However another consideration, I grow in sphagnum and bark rather than Semi-Hydro so what works for me might not work for you, Phal modesta is also a bit more tolerant of cool temperatures than P. bellina but the things above should still apply.

[Roberta]

Even in nature orchids don't get 100 deg F at night even if they get temperatures that high by day. I would expect that the normal natural range is more like 72-25 deg F at night, maybe 85-90 deg F during the day, with very high humidity (like 80% or more)

[MateoinLosAngeles]

Originally Posted by Roberta

I would expect that the normal natural range is more like 72-25 deg F at night, maybe 85-90 deg F during the day, with very high humidity (like 80% or more)

That's not necessarily true for the Phal bellina. In Borneo the lowest average night temperature is 74ºF. The average annual temperature accounting for day and night is a consistent 82ºF.

The average day temperature is 89.6ºF, Borneo experiences almost uniform temperature and humidity throughout the year as it is near the equator. Humidity stays between 80% and 90%. There is a rainy season in December and January where heavy rainfall can average 450mm per month. However, rainfall averages above 150mm monthly throughout the year. The "dry" season only experiences heavy rain showers in the afternoon. The "wet" season experiences these heavy rains throughout the day.

One could expect that the temperatures in the rainforests in the center of the island could be 5 to 10ºF higher than coastal temperatures, the Bellina grows in the lowland where it is hottest.

Phal bellina and other species originating near the equator in south east Asia are not comparable to your typical Phalaenopsis hybrid that originates in southern China, where they will experience wider temperature changes between day and night.

[Arizona Jeanie]

The basic thermostat I have on a heat mat turns the heat off when it exceeds the set temperature.
Otherwise, the mat will always be on--cooler when the room is cooler, but not cycling on/off according to the low temperature.
The thermostat's only function is to turn the mat OFF when it gets OVER the set temp.
(I hope this makes sense!) You might find it useful.