Thoughts on Blue

[MattyB]

I've been formulating some rough observations about what effects the amount of blue a palm exhibits and I was wondering what your thought are on this as well.

I always assumed, or maybe I was told, that the hotter, sunnier, and drier a species like Bismarckia, Brahea armata, Chamerops cerifera, Brahea decumbens, etc., were kept, then the more blue powdery coloration they would exhibit. But I'm starting to doubt this theory.

Paul has a super blue Brahea armata in full shade and it has access to regular irrigation.

My (7) Brahea armata seemed to be losing their blue coloration although they were all planted on a hot, south facing slope, in full sun, and watered sparingly. I decided to make a drip bucket (bucket with a tiny hole drilled into the bottom) in order to get more water to the palms in this hand watered area and now after several months of increased irrigation they all are showing more blue coloration.

I'm wondering if a palm needs water to create the blue powder and if they are left on the dry side, even being drought tolerant, they won't produce as much blue.

Are cycads like this?

Like I said, I'm just in the rough stages of observations here and haven't formulated any concrete evidence. What are your experiences?

[John Case]

You make a good point, Matt. I have a B. armata that has nev er had a drink and collects all of the heat of the day. It has blue in it, but not as blue as one may think.....maybe I'll hook up a drip to it and see what happens....

i would guess that a large amount of water would not blue it up but would cause root rot...

[LJG]

ZZZZZZZzzzzzzzzzzzzzzzzz

[John in Andalucia]

Don't forget you're only commenting on what your eyes see. Now recall how many palms photographed in the half light of morning or at dusk look more intensely blue, than when viewed or photographed in full sun. If you could take Paul's Brahea and view it in full blazing sun, would it look as blue? I think not.

[Walter John]

Hey Matty, I was always under the impression that the intense purple to silver of bizzies was a genetic event. Further study required..

[sonoranfans]

The powder on brahea armata is not blue its white. I used to have 7 from 4 to 15' overall when I lived in AZ. I watched them change color over a 5 year period, some of the ones in most intense sun became more blue, those in shade stayed the same color(some were genetically more blue perhaps). The white powder/wax reflects the light it sees, if its a blue bias sunlight it will be more blue.

The blue/red bias in sunlight color depends on moisture in the air, miles of atmosphere sun rays travel through the atmosphere, and on rayleigh scattering(if interested read up on this). Then to make things more difficult to understand there is light that is reflected off and transmitted through, leaflets. Light that enters a leaflet will come out with a bit of green in it, hence less blue(chlorophyll absorbs all but the green). I am not sure if different types of palms have different color enhancing components in chlorophyll. I do know that if I really rub a brahea armata/bizzie/cerifera leaflet it will be light green underneath with white wax on my hand as a result. Light can be transmitted through a leaflet or enter, internally reflect and come back out the same surface, in both cases more green results.

All those points taken, I would offer an interpretation that a heavier layer of white wax means more blue as long as the sunlight has a blue bias. When the wax gets really dry, it comes off the leaflet easily, and the leaflet color changes. I suspect that palms produce the wax to protect them from intense sunlight/dry atmosphere because leaflet dessication is going to be much greater if the leaflet is heated via light absorbtion. I have observed that chamaerops ceriferas are notably more "sun tough" than the green chamaerops. Brahea armata is about as sun tough as its gets, as are bismarckia silvers. I can also say that in winter they both seem to lose some wax in AZ, perhaps due to cold temps and flaking off. the was that comes off the petioles of bizzies after winter is almost like talc, and there is lots of it.

So... I guess the answers to color are more complex than the simple "put it in sun" as multiple effects are likely present. I also once saw a chamaerops cerifera "go back to green" at a 5g+ size(in the ground) after the 2007 freeze when it hit 20F in Gilbert AZ. That palm was green a few weeks after the freeze. A year and a half later in the 105+F heat of the summer, it was more blue than ever in 6+hrs/day of direct arizona sun.

[gyuseppe]

I have a Brahea armata in the sun is blue,I have 2 little Chamerops cerifera ones are always in shadow and are colored blue !

result: sun = blue - shadow = blue

[paulgila]

matt leave me out of yer crazy "theories" from now on.

i am going home to dig that palm up.

[John in Andalucia]

I have a Brahea armata in the sun is blue,I have 2 little Chamerops cerifera ones are always in shadow and are colored blue !

result: sun = blue - shadow = blue

blue + shadow = blue + 1 more!

[Davidl]

I am not sure about less water making Bismarkia's blue but more sun seems to make them more blue/silver.

[John Case]

ZZZZZZZzzzzzzzzzzzzzzzzz

Riveting, isn't it Len?

[iamjv]

I saw Tony C's armata in Dallas this past weekend and it is struggling for light between the wall of bamboo and other palms around it, and it is as powdery blue/white as can be.... he doesn't water it much so it must also enjoy the hot dry conditions. Jv

[Jeff Searle]

I've been formulating some rough observations about what effects the amount of blue a palm exhibits and I was wondering what your thought are on this as well.

I always assumed, or maybe I was told, that the hotter, sunnier, and drier a species like Bismarckia, Brahea armata, Chamerops cerifera, Brahea decumbens, etc., were kept, then the more blue powdery coloration they would exhibit. But I'm starting to doubt this theory.

Paul has a super blue Brahea armata in full shade and it has access to regular irrigation.

My (7) Brahea armata seemed to be losing their blue coloration although they were all planted on a hot, south facing slope, in full sun, and watered sparingly. I decided to make a drip bucket (bucket with a tiny hole drilled into the bottom) in order to get more water to the palms in this hand watered area and now after several months of increased irrigation they all are showing more blue coloration.

I'm wondering if a palm needs water to create the blue powder and if they are left on the dry side, even being drought tolerant, they won't produce as much blue.

Are cycads like this?

Like I said, I'm just in the rough stages of observations here and haven't formulated any concrete evidence. What are your experiences?

[/quote

I think if Paul is part of some "observation", then at the very least, he should of thought ahead and posted some pictures. This is sooooo incomplete. Moderator?

[paulgila]

i agree,i should HAVE.i take full responsibility. feel free to remove this entire thread.

[ariscott]

I thought I would answer.... My bismarkia is in the full sun... very blue/silver/whatever you call it, but it has access to plenty of water as we irrigate during the dry season... There you go, just to confuse you...

Regards, Ari

[Kumar]

Hyphanae is blue -silver too, and produces a large amount of that white talc-like powder. Mine is getting good at it despite being in a perpetually flooded pot for weeks.

[Geoff]

I am pretty sure the primary factor in determining how much blue a palm or cycad has (ie. white wax on a green leaf) is genetic. However, secondarily, at least in many cycad species, lack of bright sunlight over time will decrease blueness (wax production) to some degree (blue Cycads grown in deep shade will become green or mostly so I have learned... and also less healthy, too). If plenty of sun, the more water a palm gets, the healthier leaves it produces and likely the maximum amount of wax will be formed as well... so more water might mean same or more wax (ie. same to more blue color), but certainly not less. Palms watered very little will produce leaves more slowly, allowing the existing leaves more time for the wax to wear off (therefore less blue)... so poorly watered palms may, over time, look less blue. Also the new, possibly less healthy leaves. that come out more slowly due to the lack of water (and possibly lack of nutrients as well, as the two go hand in hand in most non-excessivly watered or nutrient deficient soil situations) might have less wax on them (ie less blue). This theory is totally made up, however, and you can put all the holes in it you want... but I think I am correct.

[Kumar]

Another half-baked theory, palms that can grow in full sun will usually have darker green leaves than those that don't. Even new leaves of such palms are lighter when they emerge and gradually turn dark with exposure. So to explain how these 'blue' palms have such light leaves despite being in even more sun than the 'dark greens', either the colour is unconnected with the amount of sunlight received or that powder they produce substitutes the need for a darker green colour.

[sonoranfans]

I am pretty sure the primary factor in determining how much blue a palm or cycad has (ie. white wax on a green leaf) is genetic. However, secondarily, at least in many cycad species, lack of bright sunlight over time will decrease blueness (wax production) to some degree (blue Cycads grown in deep shade will become green or mostly so I have learned... and also less healthy, too). If plenty of sun, the more water a palm gets, the healthier leaves it produces and likely the maximum amount of wax will be formed as well... so more water might mean same or more wax (ie. same to more blue color), but certainly not less. Palms watered very little will produce leaves more slowly, allowing the existing leaves more time for the wax to wear off (therefore less blue)... so poorly watered palms may, over time, look less blue. Also the new, possibly less healthy leaves. that come out more slowly due to the lack of water (and possibly lack of nutrients as well, as the two go hand in hand in most non-excessivly watered or nutrient deficient soil situations) might have less wax on them (ie less blue). This theory is totally made up, however, and you can put all the holes in it you want... but I think I am correct.

I like this explanation, the older the leaflet, the less the wax. This I can say I have observed in all cases on a given palm, except emerging fronds. If fronds are produced more quickly, as occurs with generous watering in the heat, these palms should be more "blue". The wax reflects the light and prevents it from entering the leaflet(less green). The oldest, most weathered fronds seem to always have less wax, even on my current florida grown bizzies.

By the way, my experience in the arizona heat is that it is good to give brahea armatas plenty of water if drainage is good. I had my drip system delivering 48 gallons per large(12-15') tree once a week, and 18 gallons per tree at mid week in the 100F+ season. I would cut back the mid week watering when the daytime high fell below 100F. They also like sunlight(grow faster), but the ones that dont get water tend to hold less fronds and look less stunning(as I have seen when an irrigation line failed).

[Vincent]

Regarding cycads and blue color, I was told once that the blue wax washes off in the rain. That is clearly the wrong answer as we in SW Florida have had incredible amounts of rain so far this year and my blue encephalartos are still very blue. They are in full sun, get full rain and are fully blue. I also agree that there is a genetic link for "blueness" as I have seen some really good cycad gardens (not like my garden wannabe)where there are "powder" blue and "neon" blue of the same species of encephalartos, with the difference being visible a mile away; one variety is far more blue. You don't get an apple from a mango tree.

[garrytsen]

First before we talk about blue coloration of palms, we gotta understand two issues, first,the blu tinge is caused by the presence of white powder or wax or fur on the upper leave surface and underneath.The mix of green and white therefore gives us a color of powdery green, or blue, or silver or white depending on the density of white stuff on the palms.

Second, why do the palms put out the white powder or stuff whereas others don't ?

The presence of the white powder is to protect the palms from sunlight or cold harm in the form of water loss under unfavorable dry or cold conditions. I could cite some of my experience with local Chinese palms and cycads. Say, the seedlings of Cycas debaoensis and Cycas micholitzii which are naturally growing on the limestone are bit of powdery green and turn into glossy dark green when older whereas Cycas panzhihuanensis stay blue as they are from the hot dry valleys .

Trachycarpus princeps as the only blue Trachycarpus is quite unique for the white powder powder on leaf upperside ,lowerside and petioles. They growing at the steep cliff as high as over 2000m in altitude could be the most to be hurt by ultraviolet radiation and dramatic day and night temperature fluctuation in the habitat. So the white powder makes them better suitable for these conditions .

http://www.palmtalk.org/forum/index.php?showtopic=24720&st=0&p=411257&fromsearch=1&#entry411257

In all, whether the palms are blue or not is first determined by their genetic variations. Therefore,it makes sense that some individuals even in shade could be more blue than others of the same species in full sun.

Also the growing conditions play a part in the difference.Based on my observation, sunlight definitely makes the palms more blue which coincides with their protection mechanism.Bismarkis silver are looking pretty blue or silver in the full sun and so are Butia capitata.

Whether more water makes them more blue is hard to judge but what is certain is that too much water is normally the main cause for the palm root or spear rot especially if the growing medium does not drain well. Likewise, palms growing in the fertile conditions also look less blue than those in sterile ones possibly because the appearance of white powder or stuff of greater importance in protecting the relatively weaker palms from sunlight or cold damage in these conditions than in the fertile ones.

[peachy]

My Bismarckia is in full sun, gets plenty of water and in summer it's quite blue/silver. In winter with the weaker sunlight and cold weather it reverts to the pinkish purple shades.

Peachy

[dan.vagnoni]

I'm not really sure, but could soil be a factor too? I've heard that serpentine soils can bring out color in some palms. I remember hearing that Coccothrinax sp. azul will only develop its habitat-like color, if its subjected to the same concentration of toxic metals( cobalt, nickel, ect.) I know there can also be color variations in some of the bigger Copernicias, could this be a similar attribute?

[sonoranfans]

I would add that the "protection mechanism" of the wax Garry referred to is of interest to this discussion. Some of the toughest palms in sun are blue/white: brahea armata, bismarckia, phoenix dactylifera, nannorrhops, and chamaerops cerifera to name a few. These palms also are not the fastest growers, especially if they can be compared to a green variant(eg.,Bizzies,ceriferas vs green variant). It could be that a particular species of palm can sense the sunlight and it responds with less wax if the light is lower to enhance photosynthesis. That is, a blue palm in deep shade might not be getting enough light for most productive photosynthesis and hence it may limit wax production to adapt to its conditions. I have seen this in my chamaerops ceriferas, quite green in the shadehouse, blued up fantastically a year after they were put in full sun, and as shade grew over them, they shaded towards greened again. Some species color might more genetically vs environmentally governed. Then of course to remind that rayleigh scattering of the suns rays creates a blue bias(like angles of colored light from a prism) at times of the year and times of the day. Its also true that the position of the palm, the sun, and the observer will effect the amount of transmitted(green) vs reflected(blue) light and that will influence the degree of blue color.

[JungleGina]

I recently joined the bromeliad society here and the speaker at the last meeting was talking about the role of silver on bromeliads. I grow bamboo and there is also a powdery bloom on some of the "blue" bamboos, which eventually disappears with time and age leaving it green. On bromeliads, they're called trichomes and are actually fuzzy scales on the leaf that serve to protect the leaves from overexposure to sun and help to conserve moisture. The bloom on the bamboos serves the same purpose and I must assume it does on the palms as well. In bromeliads, the trichomes also contain resins that repel insects.