Palm growth data and method

[PalmGuyWC]

I have a P. TVT and a Butia X Parajubaea growing near each other growing under the same conditions. They are both about the same size and have fronds about 8 feet long. Both are forming trunks. For the past 7 days I have marked the emerging spheres every 24 hours. To be accurate, I drove a narrow bamboo stake into the ground next to the trunks and I would mark the emerging sphere at the top of the bamboo stake.

In 7 days the Parajubaea grew 5.5 inches and the hybrid grew 9.5 inches. Over the 7 day period the 24 hr growth was equal each day. We have just ended a period of very warm weather, so it will be interesting to see what the growth is with cooler weather which began yesterday.

I'm curious how fast tropical palms grow each day. Anyone marking their palms?

Dick

[Mark Heath]

Dick,

Please remind me next spring to do so. My palms wont grow much this winter, well maybe the BxP. I see cooler temps coming and it is alot sooner than i can remember, looks like we'll have a long winter here in Florida.

I usually allways wear summer clothes during Thanksgiving, but not this year i fear!

BTW, is your BxP flowering yet??? I have kept a close eye on mine and i still have to wait some more. Yours is the largest, that is why i am asking.

[freakypalmguy]

I have a P. TVT and a Butia X Parajubaea growing near each other growing under the same conditions. They are both about the same size and have fronds about 8 feet long. Both are forming trunks. For the past 7 days I have marked the emerging spheres every 24 hours. To be accurate, I drove a narrow bamboo stake into the ground next to the trunks and I would mark the emerging sphere at the top of the bamboo stake.

In 7 days the Parajubaea grew 5.5 inches and the hybrid grew 9.5 inches. Over the 7 day period the 24 hr growth was equal each day. We have just ended a period of very warm weather, so it will be interesting to see what the growth is with cooler weather which began yesterday.

I'm curious how fast tropical palms grow each day. Anyone marking their palms?

Dick

Dick,

This should be very interesting to see the change in growth rate at the different temps and be able to see what is ideal. It's been smoking hot here as well lately, just cooling off today, everything is putting out a lot of new growth, especially Bismarkia, they seem to thrive in it.

I look forward to hearing the results of the growth rate in the cooler temps.

Matt

[mnorell]

Dick--

My palms are I think in general much (much!) smaller than yours as I have a very young garden here, so they don't push fantastic amounts in their youth, but I do periodically mark spears on those that are easily discernible:

- Chuniophoenix nana (my new favorite palm!) is new in the garden this year but even small 3-leaf seedlings seem to push a little under 1/4" daily, my larger specimen was planted in stressed (and nearly defoliated from bare-rooting) condition and is now recovering, probably at about 3/8" per day. I think once established this will be faster than Rhapis. Just not sure if it's as cold-hardy...

- Dypsis pembana and Kentiopsis oliviformis, both being about 1-gallon size, planted last year and being mostly defoliated from hard freezes to mulch-level, have thrown 3-4 new leaves (none stunted) in a half-sun area, and they both push spears at about 1/2" per night.

- Ravenea glauca is almost 1/2" daily in sun, but it is glacially slow in shade. All the Ravaneas behave that way and are horribly slow for me without full sun (sambiranensis, robustior, I think just 1-2 fronds per year!). Have you had any luck with any Raveneas in Walnut Creek?

- A small Schippia concolor is opening its fourth leaf in shade after being mostly defoliated by cold, it's not a speed demon, probably 1/4" per night but it really does crank steadily!

- Newly planted 1' tall Dypsis saintelucei and Dypsis lanceolata grow also at about 1/2" per night, they are quite fast even as they establish their root-systems.

- Dypsis decipiens puts on 1/2" per night in late spring and early summer, but by this time of year bananas and other foliage have overwhelmed it and new spears emerge at about 1/4" daily (It definitely wants full sun!).

- A newly planted F2 Syagrus x montgomeryana is slow, perhaps 1/8" per day in half-shade, as are several xButyagrus I've recently planted out. I assume these will speed up next year...

- A newly planted, strapleaf Syagrus picrophylla is also in the 1/2" area, as is Syagrus cearensis. The leaves of cearensis seem particularly tough, almost the consistency of Sabal leaves, and I wonder if they aren't more frost-hardy as well. I will find out this winter!

- A Syagrus 'litoralis' I planted two years ago is still pushing strapleaves at an extremely slow rate, I haven't marked it but probably less than 1/4" per day, though it's never been damaged in the least by long, hard freezes to the low 20s.

- Syagrus flexuosa pushes at probably 3/4" per day in sun, it must be my fastest growing small palm as it has put on four very nice leaves since being defoliated by freezes last winter.

- S. botryophora has just gone pinnate and is pushing at a decent rate even in a rather shaded, protected spot. I haven't marked it this season but I should do so, to see if there's an acceleration. In the past it has put on two or maybe three leaves after a typical 60% winter defoliation, about 1/4" per day. Hopefully this will speed up now.

- Arenga engleri puts on about two leaves per year, but these are getting progressively larger and are quite impressive now considering they are only a couple years old. I'll have to mark them to see the increase in inches per night.

Obviously as palms get larger those nocturnal rates, judged in inches of spear-push, will amplify as leaf and root-area, and thus sugar and tissue production, increases. Ultimately I think leaves per year is a better way to judge growth-rate because of that reason, but it sure is fun to mark the spears and look at the change overnight!

I don't bother with measuring Sabals, I just get a general ideas of fronds per year...but here my sun-drenched S. palmetto are about 8' from seedlings five years ago, and put on a good number of leaves per year; the more shaded S. causiarium and mexicana are about the same in height but with fewer, larger leaves, with longer petioles, since I have them in less sunny positions. Shade-grown S. palmetto sulks and grows very slowly. My Rhapis excelsa are bewildering to navigate for growth-measurement since they never get damaged and thus look like a mass of leaves year-round, but they do beautifully here and grow at a decent clip (3' to 7' in four years), as does my multifida, and even two very young laosensis have grown very nicely (3-4 leaves per stem) after being either damaged or cane-killed last winter. Livistona chinensis throws many leaves per year in sun, about four in shade, and saribus about four huge leaves per year in rich soil and partial sun, but this species can be very slow if in an area not to its liking. Phoenix sylvestris is just about impossible to measure, but it is easily the fastest-growing, largest palm I have, I have a silver 'robusta' form that was a seedling 4-5 years ago and now is maybe 12' tall with many, many fronds and a very big base. It is spectacular and very dangerous at present!

It would be very interesting to somehow compare species' growth-rates in the various climate-zones represented on this forum. That would be very valuable in determining optimal (or even barely appropriate) climates for many species, don't you think? Perhaps that's an idea for a new sub-forum like the freeze-damage area?

I'll try to mark some spears over the next week and post some more accurate results. We have two chilly nights ahead (lows in the 50s) so I'll see if that makes any difference as well.

[thestales]

Dick,

I saw the same thing with nights in the low 50's and days in only the 60's and 70's.

The two pictures are 20 days apart and this plant was just planted in august.

speed demon even in cool weather.

[PalmGuyWC]

Mark,

It's hard for me to judge when my Butia X Para will bloom, but at it's present rate of growth and size, I would estimate it will bloom in about 2 years from now. The base is about 14" in diamater and the trunk is begining to swell. The heavy excelsa along the trunk is now about sholder high. Our weather changed this week from swealtering hot, to cool and I expect the growth will slow down soon. My low this morning is 47F which is the first time this season the low has fallen below 50F. Last week the lows were in the lower 60's, and the highs in the 90's which is warm for N. Calif. The B X P holds over twice as many fronds as does the Parajubaea TVT growing near it.

James,

Is the picture you posted a Parajubaea or a Parajubaea hybrid?

Dick

[thestales]

Dick,

It is just a standard P. TVT. The Butia x P.TVT is still only on its third leaf according to Patric and he recommended I wait on purchasing one. I am so amazed at the cold hardiness of the BxP.C hybrid that I think the BxP.TVT should be a real winner for me.

I know what I want for christmas..

[plamfrong]

Dick, unless I'm confused - didn't your P. TVT get half its fronds trimmed off by mistake a couple months ago? Could that have reduced its vigor? How many new fronds has it produced since that misfortune occurred?

[PalmGuyWC]

Dick,

It is just a standard P. TVT. The Butia x P.TVT is still only on its third leaf according to Patric and he recommended I wait on purchasing one. I am so amazed at the cold hardiness of the BxP.C hybrid that I think the BxP.TVT should be a real winner for me.

I know what I want for christmas..

Hi Ian,

Yes, you are correct, but I may have over reacted. It was not half, but maybe 6 of the lower fronds that were cut off my P. TVT. They were still green and presumably still making food, but I don't think it affected the growth of the palm that much. Actually, now that I've gotten used to seeing it as it is, it looks better and now I can see some trunk.

There is a school of thought that by removing the lower fronds it promotes growth from the emerging fronds, but I don't know if I agree with that.

I am also looking forward to trying a Butia X P. TVT, as it may be a little more hardy and robust than B X P.C. Also Butia X P. sunkha should be nice too, but they are only small seedlings. I'm told P. sunkha is the most cold hardy of the group.

Dick

[thestales]

Why would sunkha be the most hardy? The only way I think it would be hardier is that it can tolerate more moisture, making it less susceptible to rot. I thought that Sunkha grew at lower elevations in wetter areas with less frost? I also understand that while TVT grows at higher elevations, that the Microcarpa(microcarpum) variety has a wider range possibly making it hardier than TVT. Let me know what you have found.

I have a smaller Sunkha that is planted in a 15 gallon container that has yet to go pinnate, but has the begginings of an actual trunk, and it will go out next year. I also planted a 5 gallon strap leafed Microcarpa in the ground that has barely moved all since July, but has access to much less light.

I have a few "extra" sunkhas that I can give to some cold hardy testing, but I would rather wait until next year when they are more established and have an actual chance.

[PalmGuyWC]

Ian,

I can't verify which Parajubaea is the most cold hardy. I have some that are pinnate growing in 5 gal containers, but they are under lathe in the winter, but get a lot of direct sun with the low winter sun angle. My experience has been they will take it down to 25F, but they don't like frost on the foliage below 27 or so. I think they will survive much lower temps. but with foliage damage. Mine will be treated with Frost Pruf this winter.

Dick

[PalmGuyWC]

I think I have made an interesting discovery. As we all know, palms do their growing at night, but not during the day. I have been marking the emerging spheres around 8:30 AM and then checking it about 4 hours later. It appears to me that the emerging frond actually recedes a fraction of an inch during daylight hours, about the width of a felt pen line. This seems totally amazing to me. 24 hours later, after darkness, the emerging fronds have grown about an inch, give or take a little. Has anyone else observed this?

Dick

[thestales]

Holy moly, that's interesting stuff, dick.

My only guess is that it may recede during the day to conserve mositure or to protect the extreme new growth from being exposed to the sun too soon. Many plants "move" in response to day and night. Maybe palms are one of them as well but only the truly dedicated ever notice.

Good Eye, but now you have me wanting to do some major measuring in the spring.

[Nigel]

I think I have made an interesting discovery. As we all know, palms do their growing at night, but not during the day. I have been marking the emerging spheres around 8:30 AM and then checking it about 4 hours later. It appears to me that the emerging frond actually recedes a fraction of an inch during daylight hours, about the width of a felt pen line. This seems totally amazing to me. 24 hours later, after darkness, the emerging fronds have grown about an inch, give or take a little. Has anyone else observed this?

Dick

Dick, it depends on what you call growth. IE, Cell division or movement of the spear.

Real growth in terms of cell division is fairly constant I believe. The reason for contraction and growth is cell turgour.

In daytime the stomata open for photosynthesis and the plant loses water and water pressure, hence the contraction.

At night, the stomata close, and the water and materials for construction is transferred to the new cells which expand moving the spear.

[mnorell]

Dick, that's just too weird! Did you notice that on just one specimen/species or on several? I can't imagine how that would even be possible unless there's a slight dessication as humidity levels lower during the day, perhaps this would give the impression of "shrinking" as the cells contract slightly due to a reduction in water content? That's the only thing I can think of.

One thing I did notice:

- Two days ago I marked my two Dypsis pembanas (one half the size of the other), which I think may be my fastest-growing easily-marked palms, and the larger specimen, I think close to 2' tall, grew exactly an inch over the last two nights (cumulatively). The night before last was downright chilly (low 55.6F), then last night sat in the low 60s all night. Both days about 80F and sunny. Of the two pembanas, the smaller one grew exactly half as much as the larger one...which makes sense due to the difference in plant-size. As I mentioned in my earlier post I think it all winds up about equal in terms of number of leaves produced per year, because the plants are larger the spears have to travel farther to complete their growth. I wonder if anyone in South Florida with a big pembana could do a spear-mark on a large specimen and give an overnight growth-rate figure? It would be interesting to see how spear-growth changes with plant-size if other conditions are similar, and I wonder if it is linear or exponential (i.e., based on leaf surface-area and thus raw daily sugar production). Do you have any other fast-growing species (like Syagrus, Trachycarpus) with multiple specimens at different sizes that you can mark at your place in Walnut Creek to do a similar test? I'm also going to continue marking as our night-temperatures are back on the increase and lows should be in the 70F range for the next week or so, and I want to see the effects of cool evenings vs. warm evenings. I always try to mark spears in the early or middle part of their emergence because the spears obviously slow down as they near their fully grown positions.

[iamjv]

Nigel thanks for the insight.... Jv

[plamfrong]

Parajubaea sunkha comes from near Vallegrande, Bolivia which has very little (no?) frost. TVT and TVM come from higher up. From the reports I have heard, mostly back in the early part of this decade when seeds of these species were widely distributed, TVT sounds like it is a tad less hardy than the other two. But they really might all be quite similar to each other in hardiness.

How do you account for the one from a lower altitude being just as hardy as the others? I don't have the answer but here are some thoughts. When you look at wild plants many of them are surviving just on the edge of their hardiness and persisting long enough individually to maintain a stable population. (A great example would be all those treeferns that grow in frosty parts of New Zealand yet we can't grow them.) Other plants are far hardier than they need to be to survive where they are native (like Sabal causiarum and S. bermudiana). I'm not certain but Parajubaeas are likely to be relictual from a previously wider or different distribution. Probably they achieved their present distribution as a result of the relative freedom from competition with other plants, more than any other factor. Looking at native distribution alone, one wouldn't expect Butia capitata to be hardier either. In fact one would expect P. torallyi to be far better adapted to the Pacific Northwest than most of the Butias (perhaps excepting those from the frostiest areas where they grow in Brazil). But Butia (many of them anyways) seems to have superior leaf hardiness.

Take home message... it's great to know what kind of climate something comes from, but really the only way to find out how hardy something is, when definite experience/information is lacking, is to try it. That's why I'm game to try almost anything that hasn't been tried (within reason)... and why people who make claims about how hardy something something is based on the climate it comes from are not always correct. A recent example... all the "experts" were predicting Wollemia nobilis wouldn't be able to handle colder than 25F, just before it was introduced to cultivation, but that turned out to be a ridiculous assertion - it's easily much hardier than that, we now know.

Anyway for me P. TVT and TVM both lived through 19F in little pots, totally out in the open, minor damage. But I killed a TVM that I planted in the ground, from a temp. around 25F. I attribute this to different cultural practices. The potted ones hadn't been fertilized in way too long. The one in the ground was too happy. It did survive one winter with protection before dying its second winter. I haven't tried P. sunkha yet.

Nigel, interesting comments, it leads to some possible explanations of why some palms simply fail to thrive when night temperatures aren't to their liking.

Pardon me for going off topic.

[Mark Heath]

Nigel thanks for the insight.... Jv

JV,

I could'nt agree more!!!!

Wow Nigel,,, you're one smart dude!!! Thanks for the information!! I am constantly reminded here of just how basic

my thought process is!!! I have so much to learn!!

Keep it coming guys!!

Dick,

I can't wait to see if our BXPs' will produce viable seed!! I hope so!

[Nigel]

Wow Nigel,,, you're one smart dude!!! Thanks for the information!! I am constantly reminded here of just how basic

my thought process is!!! I have so much to learn!!

Keep it coming guys!!

Mark I am sure somebody will write something to show me as being wrong... I am just writing what I remember from 30 years ago in school in A level Biology. I was hopeless at school but because I loved science and biology it all went in and stuck without effort, unlike all my other classes !! Before my final exam the biology teacher had my parents in to the school to tell them what a waste of space I was because I had never done any homework in 2 years and was wasting my time. I got the only A grade in the whole school in biology. Failed dismally in all else.

[mnorell]

Ian--

It's interesting your experience with Parajubaeas in the PNW, and your experience that it's more than just temperatures that determine survival. Also your observations about how hardiness often strays from what "should" be based on location. Indeed, why is Sabal causiarum frost-hardy and freeze hardy down to 10F or so, whereas S. domingensis, which grows literally adjacent to S. causiarum and at a higher elevation, has frost-tender foliage but similar bud-hardiness? This kind of variation has always been something that has intrigued me, just as the issue of measuring plant growth in different climates due to differences in plant metabolism systems, etc., which is why I think Dick's question about measuring growth is really something worthwhile in pursuing via getting growth-rate data from members here in their vastly differing climates.

Here in the Deep South we have something of an opposite climate from yours, though I think we can all have occasional devastating single-digit lows of similar intensity. Parajubaeas have eluded most of us down here in the steamy semi-tropics. I had three P. sunkha that I tried and all of them either quickly or slowly rotted off. This seems at odds with the presumed adaptability of this species due to a wide variation in elevational in habitat. Yet I think Eric Schmidt has one growing happily at Leu Gardens in Orlando...so who knows what the secret is with that species. Perhaps one of these days someone will stumble upon a secret, as happened with Dypsis decipiens, which due to early failures was thought not to thrive in the warm-night climate of the southeast. Now we know all it takes is planting in a raised bed of sandy, rocky soil with the heel up and out of wetness, and they are easily grown in a variety of climates. Once I utilized this system I had a happy, healthy decipiens growing. I don't know if that would work similarly for P. sunkha, though...and I think more people are pinning hopes on hybrids with the Butiinae to solve the riddle, rather than pursuing the genus in its pure state.

[PalmGuyWC]

Gentlemen,

Thanks for your interests and imput. I think Nigel's explination is a plausible one. I noticed this phenomena several days ago, but I thought maybe I had messed up marking the emerging sphere, but it kept repeating day after day. Since I drive a bamboo stake in the ground right next to the trunks, there can be no movement of the stake. Since on both palms there are several emerging fronds at different stages of growth, it could be that the entire area of meristematic cell division shrinks, and it appears that the youngest sphere is retracting.

It's almost impossible to mark the sphers on my Tracheycarpus wagnerianus, because there are usually several spheres at varying stages of growth and they are hard to reach. One way to check the yearly growth on fan palms is to put a loose plastic band around the youngest emerging frond and then check the number of fronds above the plastic band a year later.

This past cool and late spring with night time temps. in the 40's, I noticed the T. wagnerianus had pushed out 4 new spheres before any of the other palms showed any signs of growth. In my cool winter climate virtually all palm growth ceases about the middle of Nov. and they don't resume growing until the night time temps rise above 50F in late spring. I didn't mark my Trachs this past year, but my guesstimate is they grew about 18 new fronds this growing season.

[PalmGuyWC]

Humm, my computer froze up and I couldn't finish my post. I was about finished anyway, but I was going to add that I have a Brahea elegans that grows 14 new fronds each growing season.

I encourage any of you to try marking your palms and see if you observe the same results as I did.

Dick

[Alberto]

Parajubaea sunkha comes from near Vallegrande, Bolivia which has very little (no?) frost. TVT and TVM come from higher up. From the reports I have heard, mostly back in the early part of this decade when seeds of these species were widely distributed, TVT sounds like it is a tad less hardy than the other two. But they really might all be quite similar to each other in hardiness.

How do you account for the one from a lower altitude being just as hardy as the others?

I remember Gaston Torres Vera saying that P.sunkha comes from a frosty valley where it is cold because of air drainage from higher up.... so valleys can sometimes be colder than higher places. For example:Euterpe edulis sometimes grow at higher altitude on a mountain and fail to grow near the bottom of the valley because of he cold air below....

[plamfrong]

I remember Gaston Torres Vera saying that P.sunkha comes from a frosty valley where it is cold because of air drainage from higher up.... so valleys can sometimes be colder than higher places. For example:Euterpe edulis sometimes grow at higher altitude on a mountain and fail to grow near the bottom of the valley because of he cold air below....

Thanks for that Alberto. I was making some guesses based on what I know of the climate at Samaipata, which appears to experience only the lightest of frosts if any. It may be that geography dictates a very different climate for P. sunkha despite it being at approximately the same altitude.

I am borrowing a book "Arboles y Arbustos Para Sistemas Agroforestales en los Valles Interandinos de Santa Cruz, Bolivia", which, I have just noticed, gives a broader altitude range for P. sunkha, from 1500-2700m.

Considering the complex topography and inaccessibility of a country like Bolivia, one has to wonder if a few more cocoid palms are still out there undiscovered and undocumented to this day.

[PalmGuyWC]

For the past week I've had temps. much cooler than the week before. The nightly lows have ranged from 46 to 52 degrees, day time, mid to upper 70's, and the week before the low 60's at night and 90's during the day. Just as I expected the marks on the emerging spheres have grown closer together.

During the warm week the Para. TVT grew a little less than an inch during a 24 hr. period and the Butia X Parajubaea almost an inch and a half per 24 hr. period. The Parajubaea has slowed to about 1/2 inch a 24 hr. period, and the Butia X Parajubaea to 1 inch per 24 hr. period.

I will try to continue this process until the nights drop into the 40's or 30's. Seems like the low 60's night time are ideal for growth of these palms.

Dick

[thestales]

I would be very interested to know which palms grew the fastest with nighttime temps in the 40's. That's one of the reasons I like the Parajubaea is that they still put on growth with nights in the 40's and cool days. That's what I need in a palm, Something that can grow well when the temps are from 40-60, as that is what I have 8 months out of the year.

I will be watching your fall growth rate intently.

[Axel Amsterdam]

My small parajub TVT has been growing slowly (a couple of millimeters per 24h) during the last nights with temps in the low and high 40's. My butia capitata is growing at the same pace though.

[PalmGuyWC]

I guess it doesn't take a rocket scientiest to figure out that the warmer the temps, day and night, the faster palms will grow. I'm continuing to mark my Parajubaea TVT and Butia X Parajubaea every 24 hours. With shorter days and cooler nights the hybrid continues to grow about twice as fast as the P. TVT., almost an inch a night.

Dick

[Patrick]

That's pretty good, still Dick! I do need to look into getting one of those for my place!

Pat

I guess it doesn't take a rocket scientiest to figure out that the warmer the temps, day and night, the faster palms will grow. I'm continuing to mark my Parajubaea TVT and Butia X Parajubaea every 24 hours. With shorter days and cooler nights the hybrid continues to grow about twice as fast as the P. TVT., almost an inch a night.

Dick

[PalmGuyWC]

Pat,

You should get one of the Butia X Parajubaeas while they are available. You have a good climate for them. They are expensive but worth it, and they grow very fast. Just remember, they are going to be a large palm and like plenty of sun. I only know of 5 people in N. Calif. that have one.

Dick

[thestales]

Almost Another Month and still growing. One odd radiational freeze of 30 (record setting low for the day) didn't phase it. Night time Temps in the mid 40's, Day time Temps high 50's to low 60's. The past two weeks have finally thoroughly moistend my sand and gravel soil. Max average rain during winter is about 3 inches a month at the wettest.

[PalmGuyWC]

I have continued my little experiment of marking the growth rate of the emerging spear of a Parajubaea TVT and a Butia X Parajubaea hybrid. As the days grow shorter and the nights cooler, the growth has slowed to about half of what it was the last week of Sept. when daytime temps were in the 90's and nights in the mid to low 60's. It's a myth that Parajubaeas grow faster in very cool temps. Night time temps in the high 50's to 60's seem to be optimum for the Parajubaeas.

My night time minumums are now in the 40's and day time in the 70's. I shall continue this experiment until my minumums fall into the 30's. The P. TVT hybrid is growing almost twice as fast as the pure Para. TVT, and it's considerably hardier to cold than pure Parajubaea. For those of you who experience frost and chilly winters, I would highly recommend Butia X Parajubaea.

To be continued...........

Dick

[PalmGuyWC]

CORRECTION........

The Parajubaea hybrid is a Butia X Parajubaea cocoides, not a Para. TVT.

Dick

[Axel Amsterdam]

I have continued my little experiment of marking the growth rate of the emerging spear of a Parajubaea TVT and a Butia X Parajubaea hybrid. As the days grow shorter and the nights cooler, the growth has slowed to about half of what it was the last week of Sept. when daytime temps were in the 90's and nights in the mid to low 60's. It's a myth that Parajubaeas grow faster in very cool temps. Night time temps in the high 50's to 60's seem to be optimum for the Parajubaeas.

My night time minumums are now in the 40's and day time in the 70's. I shall continue this experiment until my minumums fall into the 30's. The P. TVT hybrid is growing almost twice as fast as the pure Para. TVT, and it's considerably hardier to cold than pure Parajubaea. For those of you who experience frost and chilly winters, I would highly recommend Butia X Parajubaea.

To be continued...........

Dick

Hi Dick,

Have you noticed any change in growthrates recently or is the weather/growth pretty stabile during the last few weeks?

I love to know what the parajub is doing.

Thanks,

Axel

[freakypalmguy]

I just marked a couple of spears yesterday and today I found:

Bismarkia - no growth - obviously needs a lot of heat

Butia compacta - about 1/16"

Dypsis decipiens - 1/4" This one surprised me.

[PalmGuyWC]

In the past week or so my temps. have cooled considerably to mid 60's daytime and 40's at night. The Parajubaea TVT has slowed to about 1/3" a night and the Butia X Parajubaea to about 1/2" a night.

Dick

[PalmGuyWC]

For the past week my night time temprature lows have been in the mid 40's to high 30's, and day time in the mid 60's. The sphere growth on both palms has slowed to about 1/8" a night. The growth rate has slowly deminished as the days get shorter and the temps lower, about what I expected. I'm discontinueing my experiment, but I'll do it again next summer when both palms should be at max growth. The Butia X Parajubaea has grown about half again faster than the the Para TVT. One thing I have learned from this is that palms do all of their growing at night and not at all during daylight hours.

Dick

[thestales]

The hours of light have diminished and the angle of the sun has gone down low enough to block all the morning sun for this torallyi. Growth is slowing but still noticeable. Aside from a couple nights in the high 30's or so, nights have been in the 40's, and days in the 40's and 50's. The other day I had a high of 48 and a low of 49...if that makes sense. Rain and mist is becoming more consistent with about 2 and half inches for this month already. Thankfully the soil is well drained and the opuntia fragilis planted with it is doing okay, but I am still concerned for its dryness.

[PalmGuyWC]

I guess I will have to eat my words. I always had assumed that palms ceased to grow once the night temps. fell below 50F. I quit marking my Para TVT and the Butia X Para about a month ago when their growth had slowed to about 1/8" a night. The last part of Nov. and all of Dec. I've experienced some chilly nights with light frost to a couple of nights of a hard freeze in early Dec. The day time temps never got above 50F several days in Dec.

I checked the palms today and was surprised that the newest emerging spear had grown several inches on both palms. For the past week it has been somewhat warmer here. I also noticed that the base of the trunks are continueing to expand even though the foliage growth has slowed down. I did get a couple of nice rains during this period, about 7", so that may have something to do with it.

Dick

[iamjv]

I continue to see growth albeit very small amounts on my hybrids as well... we've had a colder start to winter than normal and have already seen a hard freeze recording 21.9 F in the yard. All the butia/parajub/jubaea/syagrus hybrids came through with no damage, while other phoenix hybrids didn't fair as well. (You can see my full report on my central Texas damage thread.) Keep on checking the growth rate. Jv