Trachycarpus fortunei in Colorado Springs Protection

[Palmphile]

Hi. I was wondering if anyone has any tips on getting my windmill palm to live through a Colorado winter. I’m in zone 5b. Here is my current set up. I have a 4 inch layer of mulch with a heat cable on the surface and wrapped around the trunk and covered with burlap. There are also lights on the outside that put off a little heat. The plastic layer on the shelter is 4 mil. Thanks (p.s it’s cold here!)

Edited October 27, 2022 by Palmphile

[Alex Zone 5]

I think you're good to go 👍

You might want to hang a wireless thermometer to keep an eye on inside temperatures. Make shure heat can escape on warmer days.

Best of luck. 

[Allen]

I would think about putting a wireless thermometer in there.  I'd replace the plastic with foamboard and have a sold top for ice/snow load for 5b.  The heat cable needs to be temp regulated and the lights need to be incandescent on a thermocube.  The burlap wrap inside needs to go higher up the palm almost to the top.

 

 

Edited October 28, 2022 by Allen

[jwitt]

I would put that biggest rock to the right of the cube inside the cube at the base of the palm on it's north side. 

Nice job and good luck!

Edited October 28, 2022 by jwitt
Add picture

[BeyondTheGarden]

2 hours ago, Allen said:

I would think about putting a wireless thermometer in there.  I'd replace the plastic with foamboard and have a sold top for ice/snow load for 5b....

You really don't know what's going on inside your box unless you have a temp probe in there (ideally one that you can monitor remotely).  I also agree with the foamboard.  Plastic helps to a limited degree, but not as much as dedicated insulation, which has dead space which dramatically slows heat transfer.  You can't really stop heat transfer, only slow it down.  However, you can slow it enough to effectively stop it at a certain point, based on the limited duration of ultimate night time lows, and the re-warming cycle that typically follows the next day... 

1 hour ago, jwitt said:

I would put that biggest rock to the right of the cube inside the cube at the base of the palm on it's north side....

I've tried filling buckets with water, filling ceramic pots with soil, and putting them in my greenhouse, and i haven't been able to put enough inside to make any observable difference.  I even tried heating up very large pieces of steel and ceramic pots with a propane burner (so hot that they would sizzle water), in hopes they would slowly release heat throughout the night... none of that has been able to make any kind of measurable difference.  The best defense seems to be good insulation, as well as a heater of some kind.  Propane works AWESOME but it's too difficult/expensive to automate.  Electric heat works great for small enclosures but you can only heat so much real estate on a single 15 amp circuit.  

I'm in survival mode like you are - I'm going to be out of town for many weeks in the dead of winter, and my palms will ALL have to move from my house to my greenhouse... which I need to figure out how to do a better job of heating and insulating, and lighting, or I'll end up losing thousands of dollars worth of palms in a short amount of time....

[BeyondTheGarden]

I also have to ask - how long has that Trachycarpus been in the ground?  You could move it up against the house, and build your box against the house.  Your house will emit a considerable amount of radiative heat.  

[jwitt]

8 hours ago, Jesse PNW said:

You really don't know what's going on inside your box unless you have a temp probe in there (ideally one that you can monitor remotely).  I also agree with the foamboard.  Plastic helps to a limited degree, but not as much as dedicated insulation, which has dead space which dramatically slows heat transfer.  You can't really stop heat transfer, only slow it down.  However, you can slow it enough to effectively stop it at a certain point, based on the limited duration of ultimate night time lows, and the re-warming cycle that typically follows the next day... 

I've tried filling buckets with water, filling ceramic pots with soil, and putting them in my greenhouse, and i haven't been able to put enough inside to make any observable difference.  I even tried heating up very large pieces of steel and ceramic pots with a propane burner (so hot that they would sizzle water), in hopes they would slowly release heat throughout the night... none of that has been able to make any kind of measurable difference.  The best defense seems to be good insulation, as well as a heater of some kind.  Propane works AWESOME but it's too difficult/expensive to automate.  Electric heat works great for small enclosures but you can only heat so much real estate on a single 15 amp circuit.  

I'm in survival mode like you are - I'm going to be out of town for many weeks in the dead of winter, and my palms will ALL have to move from my house to my greenhouse... which I need to figure out how to do a better job of heating and insulating, and lighting, or I'll end up losing thousands of dollars worth of palms in a short amount of time....

In winter, Colorado Springs has something the PNW doesn't. See the attached map.

Mass works in the SW,  has been used for centuries to extend zones and is proven.  

[Palmphile]

16 hours ago, Alex Zone 5 said:

I think you're good to go 👍

You might want to hang a wireless thermometer to keep an eye on inside temperatures. Make shure heat can escape on warmer days.

Best of luck. 

Thanks, do you think if I can do this method, that having clear plastic with supplemental light is better than a dark insulation box?

[Palmphile]

13 hours ago, Allen said:

I would think about putting a wireless thermometer in there.  I'd replace the plastic with foamboard and have a sold top for ice/snow load for 5b.  The heat cable needs to be temp regulated and the lights need to be incandescent on a thermocube.  The burlap wrap inside needs to go higher up the palm almost to the top.

 

 

I have seen many people do foam board for the zone 6 and below. My two questions are, how does the palm tree stay healthy and live in darkness for 5 months? The UV rays are strong here so wouldn't this method of thin plastic work better than say zone 5b Massachusetts because it would heat more effectively in the winter daytime? I do have a thermocube inside that is set between 35 and 45.

[Allen]

8 minutes ago, Palmphile said:

I have seen many people do foam board for the zone 6 and below. My two questions are, how does the palm tree stay healthy and live in darkness for 5 months? The UV rays are strong here so wouldn't this method of thin plastic work better than say zone 5b Massachusetts because it would heat more effectively in the winter daytime? I do have a thermocube inside that is set between 35 and 45.

There are a ton of reasons not to use plastic on a shelter.  Substitute frost cloth for it if you want to do the shelter that way.  The palm will be fine in the dark if you keep it cool.  It's a little confusing you put 6a in sig and 5b in post.

Edited October 28, 2022 by Allen

[Palmphile]

11 hours ago, Jesse PNW said:

I also have to ask - how long has that Trachycarpus been in the ground?  You could move it up against the house, and build your box against the house.  Your house will emit a considerable amount of radiative heat.  

This Trachy has been in since mid June 2022, I got it at a Home Depot in Las Vegas. Its too late now as we are already in the lower 30s and upper 20s at night in the Springs. I think with the rocks around and its 2ish ft proxmity to the corner of my house that it is getting at least some radiative heat.

[Palmphile]

13 hours ago, jwitt said:

I would put that biggest rock to the right of the cube inside the cube at the base of the palm on it's north side. 

Nice job and good luck!

Is rocking a good way to achieve some radiant heat?

[Palmphile]

11 minutes ago, Allen said:

There are a ton of reasons not to use plastic on a shelter.  Substitute frost cloth for it if you want to do the shelter that way.  The palm will be fine in the dark if you keep it cool.  It's a little confusing you put 6a in sig and 5b in post.

Yes I interchangeable use 6a and 5b because its hard to tell where that barrier is in my part of town. Maybe I will change my location to 5b. Id like to believe that im zone 6a most years but last year we got down to like -24 Fahrenheit with wind chill, could've been a freak think but going under 0 f happens more often than people would think. I feel safer using a protection method made for a climate maybe colder than mine in case of extreme lows and just the extreme temperature variance in general.

[Allen]

15 minutes ago, Palmphile said:

Yes I interchangeable use 6a and 5b because its hard to tell where that barrier is in my part of town. Maybe I will change my location to 5b. Id like to believe that im zone 6a most years but last year we got down to like -24 Fahrenheit with wind chill, could've been a freak think but going under 0 f happens more often than people would think. I feel safer using a protection method made for a climate maybe colder than mine in case of extreme lows and just the extreme temperature variance in general.

At negative 24F I strongly recommend a foamboard shelter with approx 80-100 watts of heat inside.  The temp sensor will help you get that part right. 

[BeyondTheGarden]

You don't need to count windchill, it's the actual temp that matters. 

[Allen]

42 minutes ago, Jesse PNW said:

You don't need to count windchill, it's the actual temp that matters. 

Yea I just looked at a few years of poster's temps.  I saw a -15F and quite a few below 0F.  I didn't catch that it was windchill temp.  

[BeyondTheGarden]

25 minutes ago, Allen said:

  I saw a -15F and quite a few below 0F.  I didn't catch that it was windchill temp.  

That's dang cold!  Colorado is a wonderful place, but those winters!  

[BeyondTheGarden]

3 hours ago, Palmphile said:

Yes I interchangeable use 6a and 5b because its hard to tell where that barrier is in my part of town. Maybe I will change my location to 5b. Id like to believe that im zone 6a most years but last year we got down to like -24 Fahrenheit with wind chill, could've been a freak think but going under 0 f happens more often than people would think. I feel safer using a protection method made for a climate maybe colder than mine in case of extreme lows and just the extreme temperature variance in general.

USDA zones give you a very rough idea of what might be possible but they don't mean much.  I almost wish we just didn't use them.  

[BeyondTheGarden]

6 hours ago, jwitt said:

In winter, Colorado Springs has something the PNW doesn't. See the attached map.

Mass works in the SW,  has been used for centuries to extend zones and is proven.  

Thermal mass "works", but it takes an awful lot of mass to make a measurable difference.  I have experimented with this in my own greenhouse, and measured the difference between internal and external ambient air temps.  Adding random inert objects inside of a closed container, where those objects only occupy a very small percentage of the container, is of virtually no quantifiable value.  I even played with heating up thermal mass (2 very large ceramic flower pots filled with soil, and a 5 gal bucket filled with water) with a propane heater, for several hours.  As soon as I turned off the propane, interior air temps plummetted and within a few hours, the air in the greenhouse was within 2 degrees of ambient outside air temps.  That's the exact same difference I had, without the thermal mass, and even without the propane.  

If my greenhouse was lined with a monolithic wall 18" thick made from adobe or concrete, I'm sure it would be a different story.  My point is, mass works, but it takes a lot of volume to make a difference.  I'm all for trying everything, and every little bit helps.  Unless it actually doesn't, and you need numbers to verify what actually works.  Get a temp probe, and measure temps without the rock, then measure temps with the rock, and let us know what you find.  I'm not saying this to be facetious, I have a legitimate interest and concern for protecting palms, because I do it myself, and I want to know what works, and what is not going to work. 

[Alex Zone 5]

Heck my windmill survived -27 degrees Fahrenheit, using concetre blanket and c9 Christmas lights and a thermocube to regulate temperature.  Foam board are also good. Leave then heat wire on 24 hrs and have additional heat source on thermocube. 

1 Wireless thermometer, 2 ventilation, 3 more heat then necessary.  

[jwitt]

4 hours ago, Jesse PNW said:

Thermal mass "works", but it takes an awful lot of mass to make a measurable difference.  I have experimented with this in my own greenhouse, and measured the difference between internal and external ambient air temps.  Adding random inert objects inside of a closed container, where those objects only occupy a very small percentage of the container, is of virtually no quantifiable value.  I even played with heating up thermal mass (2 very large ceramic flower pots filled with soil, and a 5 gal bucket filled with water) with a propane heater, for several hours.  As soon as I turned off the propane, interior air temps plummetted and within a few hours, the air in the greenhouse was within 2 degrees of ambient outside air temps.  That's the exact same difference I had, without the thermal mass, and even without the propane.  

If my greenhouse was lined with a monolithic wall 18" thick made from adobe or concrete, I'm sure it would be a different story.  My point is, mass works, but it takes a lot of volume to make a difference.  I'm all for trying everything, and every little bit helps.  Unless it actually doesn't, and you need numbers to verify what actually works.  Get a temp probe, and measure temps without the rock, then measure temps with the rock, and let us know what you find.  I'm not saying this to be facetious, I have a legitimate interest and concern for protecting palms, because I do it myself, and I want to know what works, and what is not going to work.

I am referring to something working at 15f and below.  

I am not talking heating air(in a greenhouse).  

Because radiation(the heat transfer used) is not conducive to heating air, but objects. 

 

 

 

 

Edited October 29, 2022 by jwitt
Clarification

[UK_Palms]

3 hours ago, Alex Zone 5 said:

Heck my windmill survived -27 degrees Fahrenheit, using concetre blanket and c9 Christmas lights and a thermocube to regulate temperature.  Foam board are also good. Leave then heat wire on 24 hrs and have additional heat source on thermocube. 

1 Wireless thermometer, 2 ventilation, 3 more heat then necessary.  

-27F is incomprehensible to me. Nowhere in the history of the UK has ever got that cold, ever! The all-time UK record low is -16F.

Fair play for getting your Trachycarpus to survive in that nonetheless! 

[jwitt]

10 hours ago, Palmphile said:

Is rocking a good way to achieve some radiant heat?

Yes.  If you can partially bury the rock(6" to a foot), it will transfer some of the ground warmth. Good sun exposure will also help even more. It will transfer heat by radiation. 

Heats objects, not air, by radiation Just like how the sun heats the earth or those patio heaters.  Your thin air also helps.  

Visible on a 15f night with an infrared camera. Especially so at 6000'!

 

 

Edited October 29, 2022 by jwitt
Clarification

[BeyondTheGarden]

Full disclosure, I'm not educated, I don't have a degree in thermodynamics (or at all).  But, I don't believe objects can heat objects by radiation (unless they emit some kind of light, electromagnetic radiation, nuclear decay, etc).  The sun can heat things via light, that's how the IR quartz heater in my greenhouse works.  But for a rock to lose heat, and transfer heat into another object that it's not in direct contact with, the heat would have to change from radiation to convection where it is moved through the air, to the object.  I believe, but I could be wrong.  

Maybe someone who has an engineering degree can speak to this.  

[JohnAndSancho]

1 hour ago, Jesse PNW said:

Full disclosure, I'm not educated, I don't have a degree in thermodynamics (or at all).  But, I don't believe objects can heat objects by radiation (unless they emit some kind of light, electromagnetic radiation, nuclear decay, etc).  The sun can heat things via light, that's how the IR quartz heater in my greenhouse works.  But for a rock to lose heat, and transfer heat into another object that it's not in direct contact with, the heat would have to change from radiation to convection where it is moved through the air, to the object.  I believe, but I could be wrong.  

Maybe someone who has an engineering degree can speak to this.  

I have a GED and this whole thread just makes me drool and stare in total incompetence 

[BeyondTheGarden]

2 minutes ago, JohnAndSancho said:

I have a GED and this whole thread just makes me drool and stare in total incompetence 

Thank God for people having done this before!  I'm riding their coat tails, and I can't imagine how much more difficult it would be growing palms in marginal climates, if the internet didn't exist yet!!

[BeyondTheGarden]

13 hours ago, Palmphile said:

This Trachy has been in since mid June 2022, I got it at a Home Depot in Las Vegas. Its too late now as we are already in the lower 30s and upper 20s at night in the Springs. I think with the rocks around and its 2ish ft proxmity to the corner of my house that it is getting at least some radiative heat.

If you're not out of town (which I often am) during the course of winter, you can change up the insulation as often as is needed.  2' is better than 10 feet, but 0' is better than 2'.   Especially when your palm may die in single digits, but you may see negative digits.  And, Trachycarpus transplant well.  All that being said, if you're wrapping the trunk, and adding lights, and an outter shell, you're probably OK.  But, the question that remains - how long do you plan to do that?  What about when your Trachycarpus is 12' tall?  Planting it up against the house may lengthen its limited life.  "Every palm dies, not every palm really lives" - Sir William Wallace, 2025

[jwitt]

9 hours ago, Jesse PNW said:

Full disclosure, I'm not educated, I don't have a degree in thermodynamics (or at all).  But, I don't believe objects can heat objects by radiation (unless they emit some kind of light, electromagnetic radiation, nuclear decay, etc).  The sun can heat things via light, that's how the IR quartz heater in my greenhouse works.  But for a rock to lose heat, and transfer heat into another object that it's not in direct contact with, the heat would have to change from radiation to convection where it is moved through the air, to the object.  I believe, but I could be wrong.  

Maybe someone who has an engineering degree can speak to this.  

The heat transfer is not caused by visible light(at least to humans).  It is done thru photons, which do emit light, just not visible to our eye.  You would need an infrared camera to see the emissivity.

The majority of the heat from the sun is not from what we see, but invisible to us.  What we see, is mostly a byproduct of the fusion.

But what I described with rocks is a small scale of how the sun heats the earth. Invisible to humans.

"Thermal radiation does not require any medium for energy transfer. In fact, energy transfer by radiation is fastest (at the speed of light) and it suffers no attenuation in a vacuum."

Colorado Springs at 6000'+ is a vacuum!

https://www.thermal-engineering.org/what-is-radiation-heat-transfer-definition/

Edited October 29, 2022 by jwitt
Add website

[jwitt]

There was a "scientist" growing a trachy unprotected (if my memory is correct) in the Springs unprotected for several years(4?).  It did mostly defoliate, but would come back.  He did all kind of tissue analysis, leaf lethality, sugar absorbtion, etc... Sadly, probably lost...

Just throwing that out there.  Other than the couple of zero events there,  a properly situated trachy is probably doable there.

Edited October 29, 2022 by jwitt

[jwitt]

If we are talking protecting a trachy to say 20f, something magical happens.  White paint even absorbs and not reflects.  Cool stuff!

Absorptivity, reflectivity, and emissivity of all bodies are dependent on the wavelength of the radiation. Due to reciprocity, absorptivity and emissivity for any particular wavelength are equal at equilibrium – a good absorber is necessarily a good emitter, and a poor absorber is a poor emitter. The temperature determines the wavelength distribution of the electromagnetic radiation. For example, the white paint in the diagram to the right is highly reflective to visible light (reflectivity about 0.80), and so appears white to the human eye due to reflecting sunlight, which has a peak wavelength of about 0.5 micrometers. However, its emissivity at a temperature of about −5 °C (23 °F), peak wavelength of about 12 micrometers, is 0.95. Thus, to thermal radiation it appears black

[Palmphile]

Hey all im glad that this thread is getting attention it is helping me I’m internalising everything I’m thinking maybe a foam structure is the best, with some experimentation and altering. These pictures are from this morning low 29f and I had a trash can over it. It will be a high of 60 today nice and sunny ☀️ 

Edited October 29, 2022 by Palmphile

[jwitt]

20 minutes ago, Palmphile said:

Hey all im glad that this thread is getting attention it is helping me I’m internalising everything I’m thinking maybe a foam structure is the best, with some experimentation and altering. These pictures are from this morning low 29f and I had a trash can over it. It will be a high of 60 today nice and sunny ☀️ 

Those temperatures are inaccurate as your emissivity is the same for all four readings, but each object your reading has a different emissivity.  

Pour a little water on that 19.2 rock and ice will form if it is 19.2f.  it won't and it isn't 19.2f. 

That species needs no protection/or heat above 20f in my mind in your climate.  Probably nearer 10f when it is established. 

Be careful with cooking it or keeping it too warm that it is actively growing. Guys who protect can help you on that, and with that said, some of the best trachies I've seen are ones protected being grown in zones 5/6!

 

 

 

[Palmphile]

11 minutes ago, jwitt said:

Those temperatures are inaccurate as your emissivity is the same for all four readings, but each object your reading has a different emissivity.  

Pour a little water on that 19.2 rock and ice will form if it is 19.2f.  it won't and it isn't 19.2f. 

That species needs no protection/or heat above 20f in my mind in your climate.  Probably nearer 10f when it is established. 

Be careful with cooking it or keeping it too warm that it is actively growing. Guys who protect can help you on that, and with that said, some of the best trachies I've seen are ones protected being grown in zones 5/6!

 

 

 

Ahh so is this temperature reading the ambient and not representative of radiant heat? So do you think that my current system with heat around the palm is too warm, what should be done to lower that temp? It usually doesn’t get below 20 until another month from now does it need no protection until then. I guess my whole plan was to build a greenhouse to allow supplemental light to continue growth in the winter but I guess with my temperature extremes foam is better.

[Palmphile]

Just now, Palmphile said:

Ahh so is this temperature reading the ambient and not representative of radiant heat? So do you think that my current system with heat around the palm is too warm, what should be done to lower that temp? It usually doesn’t get below 20 until another month from now does it need no protection until then. I guess my whole plan was to build a greenhouse to allow supplemental light to continue growth in the winter but I guess with my temperature extremes foam is better.

Also is it okay for the fronds to freeze 🥶 or have ice build up? Does it kill the frond?

[jwitt]

7 minutes ago, Palmphile said:

Also is it okay for the fronds to freeze 🥶 or have ice build up? Does it kill the frond?

My fronds are hardy to 10f. That is an established palm.  Ice is physically destructive due to the weight. I brush snow off mine with a broom. I don't protect, but am in a 7b climate. 

Ice and snow don't kill my fronds. The weight damages them.  It is the temperature.

Oh, use that rock and brush the snow.

First pic 12/19/2015 

Second 12/27/2015 same snow

Edited October 29, 2022 by jwitt
Pics

[Palmphile]

8 hours ago, Jesse PNW said:

If you're not out of town (which I often am) during the course of winter, you can change up the insulation as often as is needed.  2' is better than 10 feet, but 0' is better than 2'.   Especially when your palm may die in single digits, but you may see negative digits.  And, Trachycarpus transplant well.  All that being said, if you're wrapping the trunk, and adding lights, and an outter shell, you're probably OK.  But, the question that remains - how long do you plan to do that?  What about when your Trachycarpus is 12' tall?  Planting it up against the house may lengthen its limited life.  "Every palm dies, not every palm really lives" - Sir William Wallace, 2025

By ok do you think I can just leave it with no shelter and keep the burlap and cables with the lights over the winter?

[Palmphile]

Here is the famous Grand Junction waggie I took these pics over the summer. I think GJ is zone 7a and I think the only protection is covering the fronds no electrical heat source.

Edited October 29, 2022 by Palmphile

[jwitt]

47 minutes ago, Palmphile said:

Ahh so is this temperature reading the ambient and not representative of radiant heat? So do you think that my current system with heat around the palm is too warm, what should be done to lower that temp? It usually doesn’t get below 20 until another month from now does it need no protection until then. I guess my whole plan was to build a greenhouse to allow supplemental light to continue growth in the winter but I guess with my temperature extremes foam is better.

No the temperature is the object and not the ambient. The emissivity is part of the algorithm used to come up with the temperature.  That's why you seeing a 40f swing on objects a foot apart. There is a whole science just on emissivity!

https://www.flukeprocessinstruments.com/en-us/service-and-support/knowledge-center/infrared-technology/what-emissivity%3F

It is important to know the lethality temperature of the palm(0f?) and the leaf lethality(10f) of the same palm.  Add 5-10f to these temperatures and protect to that when established.  That's my take.

 Using a temperature probe actually touching whatever you are measuring will be more accurate unless you know the emissivity.  

You will need some protection.  An enclosure with full on heat, I'm not so sure.  

 

 

 

 

Edited October 29, 2022 by jwitt

[jwitt]

Grand Junction last winter for reference 

[DreaminAboutPalms]

Some guy got a trachy to 30 feet tall in northern Minnesota zone 3b so definitely feasible