Role of Sugars and Cold Hardiness

[Banana Belt]

60470-Article Text-111722-1-10-20101004.pdf

[Banana Belt]

Cold hardiness and sugars in a plant has been long known relationship.  Both anecdotal and scientific observations suggest that plant produce sugar compounds to enhance their cold hardiness to frost and freezing.  This opinion seems true in many different families or types of plants, for example in citrus the more cold hardy species such as Mandarins, Meyers Lemon, Kumquat and to extent Oranges are less subject to frost or even moderate freezing than any kind of Lime, Citron or other citrus with very little sugar.  Meyers lemon is a slightly sweet lemon and very cold hardy whereas Lisbon or Eureka lemons are not sweet and damaged by slight freezing. 

Could this relationship between sugars and cold hardiness be the same for Palms?  The Jubaea palm at its adult stage is full of sugar sap and is significantly more cold hardy than when it was a juvenile.  Could selective interbreeding between related palms create a hardier cross then either of the parents, or something in between?  Of course selective naturalization over generations in increasing the cold hardiness does happen, but what methods are there to increase the speed to colder temperatures adaptation?

Are there other ways to increase a palms cold hardiness to an upcoming winter, such as feeding it selective nutrients in the late summer to fall?

Just asking and wondering.

 

[jwf1983]

I’d like to know this too…

[kinzyjr]

Could make for an interesting branch of study.

[GregVirginia7]

Been wondering that myself, though from what I’ve read, photosynthesis is the driving engine rather than absorption but I water my palms pretty regularly with unsulphured molasses by hand…about 1/4 cup per gallon of water…I have a feeling it’s far more beneficial to the microbes in the soil which, in turn, benefits the palms, but if the palms can actually absorb and store any of those sugars, that would be nice. Genetics, of course has a lot to do with it as well, which is where the brilliance of cross breeding comes in…I am curious though, if there is a way to supplement the cold hardy benefits of sucrose and other sugars that would raise cold hardyness Of otherwise cold hardy palms.

[Banana Belt]

1 hour ago, GregVirginia7 said:

Been wondering that myself, though from what I’ve read, photosynthesis is the driving engine rather than absorption but I water my palms pretty regularly with unsulphured molasses by hand…about 1/4 cup per gallon of water…I have a feeling it’s far more beneficial to the microbes in the soil which, in turn, benefits the palms, but if the palms can actually absorb and store any of those sugars, that would be nice. Genetics, of course has a lot to do with it as well, which is where the brilliance of cross breeding comes in…I am curious though, if there is a way to supplement the cold hardy benefits of sucrose and other sugars that would raise cold hardyness Of otherwise cold hardy palms.

Unsulphured molasses, thats interesting and I would love to know if any sugars are actually absorbed into the palm.  Genetics and photosynthesis are the primary instructions and processes, where the tools and materials such as nutrients, microbes, fungi and tilth of the soil enable the palm to both adsorb and utilize the many compounds and minerals.  As the article mentioned the many processes plants go through during the months of colder nights and shorter days many plants produce sugars which is like anti-freeze protecting the plant from a freeze.  It would be an interesting study to find out which nutrients and or supplements and proceedures that could be applied to a palm in the months before a hard freeze.  I suspect there are ways to help a palm prepare for the cold.

[Jeff zone 8 N.C.]

I remember years ago of Plant Delights Nursery, outside of Raleigh, N.C. , (they have some palms) talking of the importance of good nutrition for plants going into winter, helping with cold hardiness. That could have been from an non natural fertilizer containing salts or from just good mulching and overall healthy plants building up sugars. I think it was one of their online video seminars. They may have info posted on line if anyone cares to search.  Also I think that it is possible that at least some plants can absorb sugars, like unsulfured molasses.  Seems to me I read somewhere that cannabis growers in California used molasses to sweeten the taste of their plants? That may mean the plants absorbed the sweet molasses.

[GregVirginia7]

To your point, molasses feeds the microorganisms in the soil that lend help and health to the palm. The sugar In molasses is ready made sucrose as it is the sludgy byproduct of making regular table sugar. Makes sense to me that if a palm can absorb nutrients in the soil, why not sucrose molecules, soluble in water and delivered by way of hand watering to be stored for later use. My cold hardy Trachy F. Is genetically wired to withstand freezing temps. So, it genetically has a way of storing and moving sugars into cells to keep them from freezing solid and bursting. I’ve seen it advance over our zone 7 winters, both arctic and mild. It does something in sub freezing weather…the segments get a blocky looking lined pattern up and down the segments…almost looks variegated…when the temps move above freezing, the segments are an even green again…observe your cold hardy fronds this winter and you’ll see what I mean if you haven’t already. The first pic below is my big, sunny Needle, the second is my Trachy that does the same thing…as well as my Brazoria and Medi no pics of them…will look this winter to see what the S. McCurtain and the Minors do the same thing…anyway, the subject fascinates me. Thanks for bringing it up. I’ve posted here in the past about the molasses/sugar theory but didn’t generate much conversation.

 

[JLM]

Interesting observations there! I would almost be curious enough to try this on Queens and see if it works for them, since its not nearly as cold hardy as the palms you mentioned.

[Banana Belt]

Many people who grow their own vegetable garden for food know that plants like Swiss Chard, Cabbage and similar, beets, carrots and many more have significantly higher sugar contents during the outset of cold weather.  The longer the plants grow during the cold season the sweeter they get.  I have been growing a vegetable garden all my life since first learning from my grandmother in middle of last century.  If anyone likes potatoes try this, after digging up the spuds let them air dry in dark cool place for a week or so then put them in a refrigerator and leave them for at least two months or more.  When you take them out of that cold storage the spuds when cooked will be as sweet as a sweet potato only better tasting.  Best spuds for this conversion of starch into sugar are Yukon Golds, Chieftains and russets.  Some potatoes don't seem to sweeten up probably because they lack certain enzymes.

I suspect there are ways to augment the cold hardiness of any palm, some more than others. 

[JLM]

10 hours ago, GregVirginia7 said:

Been wondering that myself, though from what I’ve read, photosynthesis is the driving engine rather than absorption but I water my palms pretty regularly with unsulphured molasses by hand…about 1/4 cup per gallon of water…I have a feeling it’s far more beneficial to the microbes in the soil which, in turn, benefits the palms, but if the palms can actually absorb and store any of those sugars, that would be nice. Genetics, of course has a lot to do with it as well, which is where the brilliance of cross breeding comes in…I am curious though, if there is a way to supplement the cold hardy benefits of sucrose and other sugars that would raise cold hardyness Of otherwise cold hardy palms.

Do you have a specific brand that you buy? I have some brands available but i just want to know which one works best for you. Also, how frequently do you water with this mixture?

[GregVirginia7]

1 hour ago, JLM said:

Do you have a specific brand that you buy? I have some brands available but i just want to know which one works best for you. Also, how frequently do you water with this mixture?

I buy what I can find at the grocery store as long as it’s unsulfured…sulfur is somewhat anti-microbial and that’s not good. I give each palm a gallon or so of the mix every 2-3 weeks, maybe longer…I try to rough up the top layer of soil a bit so it doesn’t just run off.  Nothing scientific, just seems to make sense. 

[Jeff zone 8 N.C.]

Since palms as well as other plants can absorb nutrients through their leaves I wonder if spraying a dilute molasses or liquid salt based fertilizer just before a bad cold spell can give a couple degrees of protection?

[teddytn]

This is a subject that’s super interesting to me. The going thought is the more summer heat and amount of sun received builds up a higher sugar concentration, in turn more cold hardiness. If that’s true then a given palm planted in Texas for example that gets a huge amount of heat and sun through the summer, would be able to handle the same low temp as somewhere father north with less damage potentially. One caveat with this is the gradual cooling in the fall before cold weather hits to acclimate or harden off, that a given locale farther north may have an advantage with. Active growth and sudden cold snap can be a big problem. Every cold event and every locale is different obviously. 

[Manalto]

34 minutes ago, teddytn said:

...the more summer heat and amount of sun received builds up a higher sugar concentration, in turn more cold hardiness. 

This is interesting to me because I thought the opposite was true. When I was in the Rio Grande Valley I was told to wait until a good chill to harvest citrus because the cold stimulates the production of sugars and produces sweeter fruit. Your thoughts on this?

Edited August 9, 2022 by Manalto

[teddytn]

12 minutes ago, Manalto said:

This is interesting to me because I thought the opposite was true. When I was in the Rio Grande Valley I was told to wait until a good chill to harvest citrus because the cold stimulates the production of sugars and produces sweeter fruit. Your thoughts on this?

Hmm maybe in regards to sugar content in fruit yeah. Don’t quote me on any of this, haven’t done the laboratory science myself obviously . Everything I read as far as sugar content in palms specifically says high summer heat produces the most sugar/ cold hardiness. 

[GregVirginia7]

8 hours ago, Manalto said:

This is interesting to me because I thought the opposite was true. When I was in the Rio Grande Valley I was told to wait until a good chill to harvest citrus because the cold stimulates the production of sugars and produces sweeter fruit. Your thoughts on this?

Makes sense since cold is the trigger to release the antifreeze so to speak…but the plant needs to have the genetic ability to store the sugars and release them when it gets cold. So I guess the more opportunity the sun gives the plant to create sugars through photosynthesis perhaps both are true…summer heat and a lot of sun increase sugar production and the storage necessary to help get cold hardy palms through cold weather and fruit trees do the same, thus sweetening the fruit…just be nice to know if you can dump low levels of dissolved sucrose in water on palm roots and have them store it up for winter or if photosynthesis is the only mechanism by which sugars are made then stored. But I’ll say again, as I showed in the photos above, when it gets sub freezing, something visually observable happens in the leaf segments and I’d love to have an expert’s opinion on that phenomena.

[teddytn]

10 minutes ago, GregVirginia7 said:

 But I’ll say again, as I showed in the photos above, when it gets sub freezing, something visually observable happens in the leaf segments and I’d love to have an expert’s opinion on that phenomena.

I missed the pics earlier. I’m no expert, but have definitely seen weird stuff happen with the leaf segments as well in cold weather. Had hoped I took a pic, looked through all my winter pics and couldn’t find one. Anyway, noticed on Sabal Birmingham the leaf segments turned a dark dark green in like a checkerboard fashion when it was single digit cold. When it warmed back up went back to normal. 

[Xenon]

9 hours ago, Manalto said:

This is interesting to me because I thought the opposite was true. When I was in the Rio Grande Valley I was told to wait until a good chill to harvest citrus because the cold stimulates the production of sugars and produces sweeter fruit. Your thoughts on this?

I heard some chilling is necessary for desirable acid-sweetness balance in some subtropical citrus like navel oranges and satsumas. I've heard navel oranges grown in tropical climates being described as bland/watered down, they do better in the highlands where they develop more balancing acidity. Holiday season Texas/Florida grapefruit is actually picked premature, the sweetest most amazing grapefruit should be left hanging on the tree until April/May. Late spring 'Marsh' grapefruit from the Indian River (FL) are sweeter than oranges! 

My favorite citrus of all, pomelo, is 100% fully tropical (sweet and cold tender). There are some sour cold hardy citrus as well such as calamondin, sour mandarins, yuzu, and sudachi. So with regards to citrus, I think provenance is really the deciding factor for cold hardiness. 

[Jeff zone 8 N.C.]

Her in N.C. it is well known that collard greens are no good until frost hits them. They then sweeten up.

[Banana Belt]

3 hours ago, GregVirginia7 said:

Makes sense since cold is the trigger to release the antifreeze so to speak…but the plant needs to have the genetic ability to store the sugars and release them when it gets cold. So I guess the more opportunity the sun gives the plant to create sugars through photosynthesis perhaps both are true…summer heat and a lot of sun increase sugar production and the storage necessary to help get cold hardy palms through cold weather and fruit trees do the same, thus sweetening the fruit…just be nice to know if you can dump low levels of dissolved sucrose in water on palm roots and have them store it up for winter or if photosynthesis is the only mechanism by which sugars are made then stored. But I’ll say again, as I showed in the photos above, when it gets sub freezing, something visually observable happens in the leaf segments and I’d love to have an expert’s opinion on that phenomena.

Or perhaps the plant produces enzymes that convert the starches it had stored up into sugars without sunlight, like a potato.  Cycads are full of starch and many are very cold hardy.  All this is just guessing and wondering.

[ZPalms]

I'll go ahead and pour some sugar cane in my pots 

[RJ]

This is common with persimmon fruit, it’s a native tress to much of the east coast. A favorite of deer if your into hunting. But the fruit is very astringent until the first hard frost, after that it sweetens up considerably.