Importance of air and soil Temps

[Plantking165]

Specifically for coconut palms whats more important during winter for overall growth, soil temperature or air temperature? What one is more important to keep the uptake of nutrients to prevent deficiency? Any experts out there that could weigh in on this? If you could add a few degrees to either one during winter for better growth and better handling the winter Temps which would it be and why? 

[kinzyjr]

9 minutes ago, Plantking165 said:

Specifically for coconut palms whats more important during winter for overall growth, soil temperature or air temperature? What one is more important to keep the uptake of nutrients to prevent deficiency? Any experts out there that could weigh in on this? If you could add a few degrees to either one during winter for better growth and better handling the winter Temps which would it be and why? 

Specifically for coconut palms whats more important during winter for overall growth, soil temperature or air temperature?

In my garden, it's soil temperature so long as the air temperature is not fatal.  Soil temperatures below 60F tend to result in nutrient deficiencies.  My coconuts grew all of last winter, even during the cold fronts in mid-to-late January.  The typical methods of increasing ground temperature include:

• Dark, stone/concrete mulch and planting beds
• Ground heating cables (I think @pj_orlando_z9b uses these)
• Temporary overhead cover each night - to keep head from radiating out of the ground and into space when they are young
• When a cold snap is preceded by a week of unseasonable warmth - soak the planting bed while it is hot out so the extra water will store more heat than the dry soil would
• Canopy modification - see below

If you could add a few degrees to either one during winter for better growth and better handling the winter Temps which would it be and why? 

I'd add the degrees to the soil with canopy to keep the heat that radiates out closer to the ground, ideally.  One practice I perform for my property that may prove helpful is fall canopy modification.  My ideal is to remove all unnecessary weight on the branches of the oaks, starting closest to the ends of the branches, to get the branch higher in the air.  This allows more fall sun underneath while maintaining the overhead protection.  Fall sun typically doesn't burn anything too badly and tends to hit at an angle that allows it under the canopy from the south.  Windbreaks help in Florida, especially to the north and west.  Since wind from the south is typically milder, you can often get away with keeping this side open to let the light in during the winter.

[Plantking165]

11 minutes ago, kinzyjr said:

Specifically for coconut palms whats more important during winter for overall growth, soil temperature or air temperature?

In my garden, it's soil temperature so long as the air temperature is not fatal.  Soil temperatures below 60F tend to result in nutrient deficiencies.  My coconuts grew all of last winter, even during the cold fronts in mid-to-late January.  The typical methods of increasing ground temperature include:

• Dark, stone/concrete mulch and planting beds
• Ground heating cables (I think @pj_orlando_z9b uses these)
• Temporary overhead cover each night - to keep head from radiating out of the ground and into space when they are young
• When a cold snap is preceded by a week of unseasonable warmth - soak the planting bed while it is hot out so the extra water will store more heat than the dry soil would
• Canopy modification - see below

If you could add a few degrees to either one during winter for better growth and better handling the winter Temps which would it be and why? 

I'd add the degrees to the soil with canopy to keep the heat that radiates out closer to the ground, ideally.  One practice I perform for my property that may prove helpful is fall canopy modification.  My ideal is to remove all unnecessary weight on the branches of the oaks, starting closest to the ends of the branches, to get the branch higher in the air.  This allows more fall sun underneath while maintaining the overhead protection.  Fall sun typically doesn't burn anything too badly and tends to hit at an angle that allows it under the canopy from the south.  Windbreaks help in Florida, especially to the north and west.  Since wind from the south is typically milder, you can often get away with keeping this side open to let the light in during the winter.

I was thinking soil temp was more important my plan is to put a heating cable in the soil around the coconut base couple ft out like a ft and a half out should be fine to keep the soil warm enough to prevent nutrient deficiency entirely so the palm can keep growing throughout winter because it doesn't look like it can afford to stop growing this winter. I'm probably gonna bury the cable just an inch below the surface as to no disturb many roots. The cable shouldn't burn the roots correct?

[kinzyjr]

@Plantking165

It shouldn't burn the roots, depending on how hot it gets.  I don't personally use any artificial heating cables.  If @pj_orlando_z9b uses them or if someone else wants to chime in, they'll have more valid input than me since I've not used them.  If you have some old C9 Christmas lights, there are a lot of people who use those to ward off foliage damage as well.  Seems like people are always selling those on Craigslist, so you might have some luck there.

[Plantking165]

1 minute ago, kinzyjr said:

@Plantking165

It shouldn't burn the roots, depending on how hot it gets.  I don't personally use any artificial heating cables.  If @pj_orlando_z9b uses them or if someone else wants to chime in, they'll have more valid input than me since I've not used them.  If you have some old C9 Christmas lights, there are a lot of people who use those to ward off foliage damage as well.  Seems like people are always selling those on Craigslist, so you might have some luck there.

Might have to look into that too, I wanna keep this palm growing during winter and avoid deficiency as it weakens the palm. My main reason is because the palm looks trashy even the new leaves are getting brown spots and patches all over not sunburn these are acclimated fronds but it worries me that I'm seeing such damage on new fronds combine disease with winter damage and deficiency your asking for a bad time so if can keep it growing and avoid deficiencies I give my plams a much better chance of survival and good health coming out of winter.

[ruskinPalms]

If you’re going to put that much effort here in Florida I’d go soil temp increase. The latitude is low enough and the sun is strong enough even on cold winter days here, which tend to be crystal clear and sunny, to warm up plants provided they see lots of sun despite the actual air temperature. And the soil warmth would help during the week or so long cold rainy spells we can get here too contrary to common belief. It is not easy to grow coconuts reliably in the middle third of the peninsula here unless you’re either water front or a block or two away from the bay, ocean, gulf or similar (maybe one of the really large natural lakes in central Florida, housing development retention ponds need not apply…). Southern exposure with good north wind blockage can help a lot but ultimately if you’re going to pay for the energy to warm something I vote for the soil. 

[sonoranfans]

Likely depends on the species and the temps.  The research I have read says yields depend more on soil temps though air is also important.  It was crop and not palm literature.  From an engineering perspective, air, a gas, is easy to heat.   It is ~ 600x lower heat capacity than a solid like rock or soil.  The problem with heating air is it blows away in wind or is naturally convective, it rises when heated.  Control airflow around the plant and air is easy to control.   Soil is best approached with a heat like a firepit but with good sized rocks near the plant for passive heat sink effects.  If I wanted to grow a coco and keep it alive in the cold I would do what Walt does, wrapped up with heating lights inside around the palm(some lights will burn so look up his posts on this) and then I would have some big rocks on the ground near the coco with perhaps a small firepit.  On a cold night burn that firepit and heat those rocks and the soil will stay warm nearby.   I might also use a space blanket 9on the ground around the palm if the cold snap was sharp and warming the next day.  A space blanked would reflect radiated heat back into the ground/rocks that you heat with the fire.  One day the coco will get big and you may not be able to wrap it though.  Its complicated and doesn't guarantee a healthy coco.  You can avoid all this by just planting a madagascan coconut, that is beccariophoenix alfredii.  Its a much better choice in 9a/b than a coconut and it will look far better than a coconut in a 9a/0b or even a cool 10a climate like mine.  If you want coconuts, you probably wont get very many in 9a/b and they might not be any good.  Guy down the street from me has a fruiting coco for the last 3 years, they never quite get to full size (a little bigger than softball size) and then they terminate and fall off.    

[Plantking165]

17 hours ago, sonoranfans said:

Likely depends on the species and the temps.  The research I have read says yields depend more on soil temps though air is also important.  It was crop and not palm literature.  From an engineering perspective, air, a gas, is easy to heat.   It is ~ 600x lower heat capacity than a solid like rock or soil.  The problem with heating air is it blows away in wind or is naturally convective, it rises when heated.  Control airflow around the plant and air is easy to control.   Soil is best approached with a heat like a firepit but with good sized rocks near the plant for passive heat sink effects.  If I wanted to grow a coco and keep it alive in the cold I would do what Walt does, wrapped up with heating lights inside around the palm(some lights will burn so look up his posts on this) and then I would have some big rocks on the ground near the coco with perhaps a small firepit.  On a cold night burn that firepit and heat those rocks and the soil will stay warm nearby.   I might also use a space blanket 9on the ground around the palm if the cold snap was sharp and warming the next day.  A space blanked would reflect radiated heat back into the ground/rocks that you heat with the fire.  One day the coco will get big and you may not be able to wrap it though.  Its complicated and doesn't guarantee a healthy coco.  You can avoid all this by just planting a madagascan coconut, that is beccariophoenix alfredii.  Its a much better choice in 9a/b than a coconut and it will look far better than a coconut in a 9a/0b or even a cool 10a climate like mine.  If you want coconuts, you probably wont get very many in 9a/b and they might not be any good.  Guy down the street from me has a fruiting coco for the last 3 years, they never quite get to full size (a little bigger than softball size) and then they terminate and fall off.    

I got 3 coconuts 2 in ground currently. I want to put a heating cable an inch down in the soil 6 inches from the base to 5ft out to keep most of the root mass warmer during winter to prevent excess damage from them being deficient due to the roots being inactive from the cold. I hope the cable won't burn the roots I only need to heat the first couple inches of soil as around 6 or more inches down usually stays warm enough for the roots. If I keep the roots active enough in winter they will uptake nutrients and keep the palm growing faster than a normal coconut in winter, atleast that is what I'm hoping for. Heating cables aren't all that expensive so it's worth a try I think.

[sonoranfans]

5 hours ago, Plantking165 said:

I got 3 coconuts 2 in ground currently. I want to put a heating cable an inch down in the soil 6 inches from the base to 5ft out to keep most of the root mass warmer during winter to prevent excess damage from them being deficient due to the roots being inactive from the cold. I hope the cable won't burn the roots I only need to heat the first couple inches of soil as around 6 or more inches down usually stays warm enough for the roots. If I keep the roots active enough in winter they will uptake nutrients and keep the palm growing faster than a normal coconut in winter, atleast that is what I'm hoping for. Heating cables aren't all that expensive so it's worth a try I think.

make sure you stop evaporation in the area around the cable as it will cool the soil off.  A space blanket would do it.

[pj_orlando_z9b]

On 9/6/2022 at 9:49 PM, kinzyjr said:

Specifically for coconut palms whats more important during winter for overall growth, soil temperature or air temperature?

In my garden, it's soil temperature so long as the air temperature is not fatal.  Soil temperatures below 60F tend to result in nutrient deficiencies.  My coconuts grew all of last winter, even during the cold fronts in mid-to-late January.  The typical methods of increasing ground temperature include:

• Dark, stone/concrete mulch and planting beds
• Ground heating cables (I think @pj_orlando_z9b uses these)
• Temporary overhead cover each night - to keep head from radiating out of the ground and into space when they are young
• When a cold snap is preceded by a week of unseasonable warmth - soak the planting bed while it is hot out so the extra water will store more heat than the dry soil would
• Canopy modification - see below

 

I fully agree with your assessment. I've found 60F soil temps to be most critical. I hit upper 50s for a week last winter and that's when I observed the mustard yellowing across the fronds.  I do not use soil heating cables. My method is I wrap C9s around the trunk for Christmas and leave them up until mid-Feb.  On nights with forecast near freezing and highs in the low 50s, I also apply burlap. With the awful weather last year of highs in the upper 40s and persistent lows in the low to mid 30s, I added a propane heater. My hope was heat would radiate up the crown. I know the trunk was at least 70F when the propane ran. 

[Plantking165]

3 minutes ago, pj_orlando_z9b said:

I fully agree with your assessment. I've found 60F soil temps to be most critical. I hit upper 50s for a week last winter and that's when I observed the mustard yellowing across the fronds.  I do not use soil heating cables. My method is I wrap C9s around the trunk for Christmas and leave them up until mid-Feb.  On nights with forecast near freezing and highs in the low 50s, I also apply burlap. With the awful weather last year of highs in the upper 40s and persistent lows in the low to mid 30s, I added a propane heater. My hope was heat would radiate up the crown. I know the trunk was at least 70F when the propane ran. 

Mine doesn't have any trunk could I just wrap the Christmas lights around the stem? It wouldn't harm it? I've heard of cables and lights burning the palm before. Also any idea if soil heating cables would burn or hurt the roots?

[pj_orlando_z9b]

On 9/9/2022 at 10:44 AM, Plantking165 said:

Mine doesn't have any trunk could I just wrap the Christmas lights around the stem? It wouldn't harm it? I've heard of cables and lights burning the palm before. Also any idea if soil heating cables would burn or hurt the roots?

If it's that young, you might be ok with mini lights with burlap around them. I've used C9s for years and never had issues. I do have a slight burn mark on my trunk but it's not from the lights. I believe it's from the propane heater. No issue with the palm though