Abscising palm fronds

[PalmGuyWC]

Somehow the idea has gotten out that the lower abscising fronds should be left on palms as it feeds nutrients into the palm. I think this is a bunch of hooey. Does anyone have any scientific proof that this is a fact? When fronds start to yellow or turn brown, I cut them off as they are not very attractive. I have never noticed any difference if the lower dying fronds are left on or removed. I realize it's best to leave crownshafted fronds to fall off at their own speed, but there are many other palms that don't self clean. Any comments?

Dick

[kahili]

I was hoping that someone would have an answer as I think its an interesting question myself.

The theory, I believe, in leaving the older leaves on is that if there is any green at all left on the leaf, that the leaf can still photosynthesize, thereby creating carbohydrates. More leaves equal more roots and vice versa.

The flipside of the question, at least for me, is whether that small amt of carbohydratest that the almost dead leaf makes makes up for the fact that the plant is investing energy trying to keep the leaf alive, when that energy could go towards new leaves etc.

Is that along the lines that you were thinking, Dick?

[gsn]

I was always under the impression strictly from what I have read, it wasn't so much about photosynthesis,because the frond is dying,therefore not producing much in the way of food. It was more about the plant absorbing(extracting) nutrients from the dying frond back into the plant.I think I read the primary thing absorbed from the dying frond was potasium. That is why alot of over trimmed palms develop an even more severe case of potasium deficiency where green material is cut away,which in theory makes sense to me.

This is just what I have read and have no scientific prove of anything I just wrote. But I did read articles from several PHD's that work with palms here in Florida,and I also stayed at a Holiday Inn Exprees last night!

So I guess I didn't answer your question,just perpetuating the common thought.

Edited August 4, 2008 by gsn

[chris.oz]

Hi Dick,

When a leaf turns brown. I cut it off too. I dont much like the brown skirt on palms.

But while leaves have green in them I tend to leave them on the palm.

There are lots of references, in the main Tim Broschats articles like the one below by Edwin Duke advise that leaves not be cut off.

http://www.famuhorticulture.com/Palms_for_...ern_Florida.pdf

Not a scientific proof though and I think its aimed at growers where the soil quality is poor and deficiencies are common.

Maybe this is more important when the palms are small. In the case of your advanced garden, trunking palms

probably would not miss a beat if you cut off the green/yellow fronds.

[Dave-Vero]

"Ornamental Palm Horticulture" by Broschat and Meerow warns against overtrimming. In particular, if a palm has nutrient deficiencie(s), the dying leaves serve as a source of nutrients--removing bad-looking leaves will simply make the newer leaves suffer nutrient problems faster.

Which reminds me that I should sprinkle some fertilizer around the yard right now.

[Ken Johnson]

I remember that the scientists measured the amounts of nutrients in old leaves and found them to be much less than in newer ones. This led to the idea that the palm was reabsorbing nutrients.

I tell people to only trim brown leaves as a rule but that with well fertilized palms a trim of a few more leaves to give a clean look to the garden for a party or PRA visit is ok.

I have seen deficient palms get trimmed untill they die. They may have died anyway but the trimming may speed it up. These people are usually not palm lovers and just don't care.

In a garden where maximum performace is required I would say the palms will be better server to cut only brown leaves. For sure this is true in commercial nurseries. Even so I see some farms that cut lots of green fronds. Sometimes they need the room for tractors to drive through and others just may be ignorant of the harm they are doing?

[ed110220]

Well I think it is accepted that as leaves start to die the plant removes all the useful substances it can from them and transfers it to other parts of the plant. How significant this is I don't know. It may not be enough to make any practical difference though to the health of the palm.

[Ken Johnson]

I think the research was stimulated in order to help people that wanted to cure sick palms.

Healthy palms can take alot of abuse before they get sick.

But again, for maximum growth don't cut green fronds. Would you guys agree to that?

[Tala]

certain elements e.g. magnesium, potassium are mobile. Monocots will move these materials from older to newer growth as needed. This is the main reason why you don't over trim palm canopies, doesn't really have much to do w/ photosynthesis. Of course over trimming doesn't help w/ that either. But as long as you do not cut "above the horizontal" on most palm canopies you can remove as many leaves as you like. Palm fronds that are in the process of abcising (this mainly for crownshaft sps.) are usually finished with this process; doubtful any elements are left in a browning frond.

[kahili]

This is all helpful and interesting. I guess I should have clarified that when I talked about photosynthesis still occurring, I was thinking of leaves that were still halfway green-not the very bottom leaves that were/are nearly brown. Would you still take these leaves off? Also, alot of my palms are still very immature, so I am interested in speeding up, or at least, not slowing down growth.

[Jim in Los Altos]

A phenomenon I've noticed in my area is that young trunking CIDPs that are routinely trimmed of many of their lower green fronds actually are growing at a much faster rate than the ones with full canopies. It's disturbing to me but I've witnessed it on many P. canariensis. Those palms carry so many fronds that the excessive pruning doesn't seem to be detrimental and, if anything, speeding growth. I haven't noticed this in any other species though.

[Tyrone]

A phenomenon I've noticed in my area is that young trunking CIDPs that are routinely trimmed of many of their lower green fronds actually are growing at a much faster rate than the ones with full canopies. It's disturbing to me but I've witnessed it on many P. canariensis. Those palms carry so many fronds that the excessive pruning doesn't seem to be detrimental and, if anything, speeding growth. I haven't noticed this in any other species though.

Jim you are the first person in the "palm community" that I've ever heard say this. I once heard an old Italian guy who grew CIDP's (the Italians love them over here, surround there properties in them sometimes) say that if you prune them regularly they grow faster. I honestly didn't believe him at all. But if you've observed this there may be some truth to it. Again, you wouldn't want to do that to a nutrient deficient CIDP, but they don't seem to mind bad soil anyway. Interesting.

Best regards

Tyrone

[_Keith]

Well Dick,

After reading all of this, I am with you. Hooey.

Trim the things to look good. Anyway, I would rather have a good looking palm that grew to 90% of its potential, than one with ratty yellow leaves that grew to 100%.

Keith

[Jim in Los Altos]

Well Dick,

After reading all of this, I am with you. Hooey.

Trim the things to look good. Anyway, I would rather have a good looking palm that grew to 90% of its potential, than one with ratty yellow leaves that grew to 100%.

Keith

Well put Keith.

[osideterry]

With Kings/Archos I used to trim any leaf that dropped below horizontal, no matter what color. I just thought they looked better. After the January 07 freeze, I want all the leaves I can get. My current goal is that I get each trunk to just have 1 pruned leaf base, no more. I'm fairly successful, and have no brown leaves either.

It has a taken a while, but my 20ft+ Queen now has a full lush crown, and zero spent leaf bases.

[paulgila]

its your garden--trim things the way you want to!

[Rusty on Pine Is.]

Just an opinion.....I doubt that there is any magical pump that "sucks" available carbohydrate back into the palm from a senecing leaf...the leaf is yellowing because the transport mechanism in the bud is differentiating into tissue that becomes vascular bundles in the trunk.

If the leaf is yellow it's because it function is finished, so it can be pruned.....if it's green it is still producing carbs and should stay.

Rusty

[PalmGuyWC]

Thanks for all of your imputs. I was only talking about removing fronds that are yellowing or already non functional and brown. My garden helper sometimes gets carried away when triming the old dead fronds off, and takes out quite a few lower green fronds too. By the end of the growing season the palms usually have a nice full crown and they don't have to be trimmed for another couple of years.

Every spring after the first heat wave the lower two ranks of fronds on my Jubaeas turn yellow, usually in just the first few days of a heat wave. I like to remove them before they turn brown as they are much eaiser to cut off before the butt turns woody and hard. I use a battery powered DeWitt saws-it to cut off old fronds on the larger palms. It makes life much eaiser. I have two battery packs so one is always charging, but I usually run out of steam before the battery does.

Dick

[FRITO]

On some palms I like te naturall skirt look and brown or yellow fronds only add character to the overall jungle look in my opinion, however there is somthing to be said for a well manicure garden also.

I personally leave all fronds on till it nearly all brown. However I dont have huge mature palms yet and trimming is still done with hand pruners on most all my palms, cant wait until I have to use a chainsaw or my Dewalt 18v sawzall like Dick does!

[xerophyte_nyc]

I would think that the reason older leaves go through senescence is because the plant has a limited ability to transport enough water, so all things being equal, a particular species can maintain x amount of leaves of any time.

Maybe removing older leaves redirects the same volume of water into fewer leaves, which in turn helps promote new growth? Maybe if old leaves are removed too soon, the plant is capable of a growth spurt with the newly available water supply and if there are not enough nutrients available to sustain the potentially fast new growth, it will present itself as a nutrient "deficiency"? Could this explain a CIDP ability to grow after being trimmed?

A wonderful experiment would be to trim off old leaves and dump extra nutrients and see if new growth can develop quickly.

Just some thoughts.

x

[BS Man about Palms]

Enough has been written about the palm being able to reuse the nutrients, that I'm gonna stick with it. I'm with the brown or down theory.

But Pohokelapa has it right, do what you want in your own garden.

Jim, I don't know if it would be easy to tell, but I would suspect that its like the overtrimmed washys we get out here. They keep trying to push up enough leaves to be happy, this gains vertical height, but as they keep trimming, the trunks are thinner and thinner. Do you think those CIDP are sacrificing girth?

BS Man

First Mate on the SS Hooey

[Tala]

BS Man you are right on target. Yes the palms (incl. canary dates) will make more leaves but they will be smaller & smaller in size, or never as robust as they could be. This in turn affects photosynthesis which effects the girth of the stems. I always get much more cash for thicker date palms. Spindly palms are like spindly women ... they fall down easy; and then you have to pick'em up.

[palmislandRandy]

"I would think that the reason older leaves go through senescence is because the plant has a limited ability to transport enough water, so all things being equal, a particular species can maintain x amount of leaves of any time.

Maybe removing older leaves redirects the same volume of water into fewer leaves, which in turn helps promote new growth? Maybe if old leaves are removed too soon, the plant is capable of a growth spurt with the newly available water supply and if there are not enough nutrients available to sustain the potentially fast new growth, it will present itself as a nutrient "deficiency"?

I had the same observation. I had a triple adonodia that had one trunk too close to the rain gutters, so I routinely trimmed only the trunk close to the house. That one trunk grew noticeably faster than the others. I believe it tried to replace fronds quicker to maintain x number of fronds that particular palm requires.

[_Keith]

BS Man you are right on target. Yes the palms (incl. canary dates) will make more leaves but they will be smaller & smaller in size, or never as robust as they could be. This in turn affects photosynthesis which effects the girth of the stems. I always get much more cash for thicker date palms. Spindly palms are like spindly women ... they fall down easy; and then you have to pick'em up.

Do you have any scientific studies to this effect?

I have heard others make this statement, but have not seen any studies to that provide evidence of this, with the exception of the process of hurricane cutting, but that is not what we are referring to here.

[BS Man about Palms]

BS Man you are right on target. Yes the palms (incl. canary dates) will make more leaves but they will be smaller & smaller in size, or never as robust as they could be. This in turn affects photosynthesis which effects the girth of the stems. I always get much more cash for thicker date palms. Spindly palms are like spindly women ... they fall down easy; and then you have to pick'em up.

Do you have any scientific studies to this effect?

I have heard others make this statement, but have not seen any studies to that provide evidence of this, with the exception of the process of hurricane cutting, but that is not what we are referring to here.

I think you had a link for this Keith?

http://donselman.homestead.com/page8.html

Look under Potassium part.

[_Keith]

BS Man you are right on target. Yes the palms (incl. canary dates) will make more leaves but they will be smaller & smaller in size, or never as robust as they could be. This in turn affects photosynthesis which effects the girth of the stems. I always get much more cash for thicker date palms. Spindly palms are like spindly women ... they fall down easy; and then you have to pick'em up.

Do you have any scientific studies to this effect?

I have heard others make this statement, but have not seen any studies to that provide evidence of this, with the exception of the process of hurricane cutting, but that is not what we are referring to here.

I think you had a link for this Keith?

http://donselman.homestead.com/page8.html

Look under Potassium part.

Hey, I remember that, but after reading it again, I think that was in a condition of potassium deficiency. Not sure if that applies if the palm has sufficient nutrient uptakes from the root system.

[DoomsDave]

Boy this is an interesting question, which I think is really several.

Does this vary by palm species?

When is a leaf senescent enough to trim off?

How do we really know any of this?

Can someone tell me?

And, who won the Lotto (not me! )

[Jim in Los Altos]

Enough has been written about the palm being able to reuse the nutrients, that I'm gonna stick with it. I'm with the brown or down theory.

But Pohokelapa has it right, do what you want in your own garden.

Jim, I don't know if it would be easy to tell, but I would suspect that its like the overtrimmed washys we get out here. They keep trying to push up enough leaves to be happy, this gains vertical height, but as they keep trimming, the trunks are thinner and thinner. Do you think those CIDP are sacrificing girth?

BS Man

First Mate on the SS Hooey

No Bill, definitely not Washys. They need all their leaves and the ones that are over trimmed around here are always stunted. The CIDPS are a different story entirely. I'm not seeing any thinning of trunks. Just major robust growth. Even on ones whose fronds are cut to 2 o clock 10 o clock positions. Strange but true.

[Tala]

Keith the omniscient Google is your friend here, I can't recall exactly where they were published but some studies were conducted out in Cal. and in Nevada, probably published in Palmcipes at the time. The UF research ctr had a few flyers out, one for Sabal (but applicable to any palm), and another for palms in general, both cover this subject as does Dr. Broschat's lit. The Nevada ext. office had the best one, at the end are recommended readings. I have the Adobe doc saved to my laptop, can send if you want. Most likely you can find it via Google as well. Here a CI Date with a large full canopy is almost always fatter than one that has been over-trimmed, even if the trimming was held in check to nothing below horizontal. I wish we could record the growth of these via time lapsed photography, surely would be evident there as well. As you probably know/observe the stems of old palms are like a time line of sorts, revealing past freezes, transplants, etc. Kinda like digging thru archaic ruins.

[_Keith]

Keith the omniscient Google is your friend here, I can't recall exactly where they were published but some studies were conducted out in Cal. and in Nevada, probably published in Palmcipes at the time. The UF research ctr had a few flyers out, one for Sabal (but applicable to any palm), and another for palms in general, both cover this subject as does Dr. Broschat's lit. The Nevada ext. office had the best one, at the end are recommended readings. I have the Adobe doc saved to my laptop, can send if you want. Most likely you can find it via Google as well. Here a CI Date with a large full canopy is almost always fatter than one that has been over-trimmed, even if the trimming was held in check to nothing below horizontal. I wish we could record the growth of these via time lapsed photography, surely would be evident there as well. As you probably know/observe the stems of old palms are like a time line of sorts, revealing past freezes, transplants, etc. Kinda like digging thru archaic ruins.

Thx. I have been researching. Unfortunately most of the info is from So. Florida whose soil (sand) and/or available nutrients bear no similarity to the clay/loam soils of So. Louisiana, or California too for that matter. Here our soils hold nutrients very well, too well in some cases. Heavy rains at times do cause leaching of certain nutrients, but primarly of nitrogen. Other than that ph needs to be monitored so that those nutrients can be absorbed. Of course here, the issue is soils sometimes being too acidic and requiring the addition of lime to unlock their potential.

[chris.oz]

Keith the omniscient Google is your friend here, I can't recall exactly where they were published but some studies were conducted out in Cal. and in Nevada, probably published in Palmcipes at the time. The UF research ctr had a few flyers out, one for Sabal (but applicable to any palm), and another for palms in general, both cover this subject as does Dr. Broschat's lit. The Nevada ext. office had the best one, at the end are recommended readings. I have the Adobe doc saved to my laptop, can send if you want. Most likely you can find it via Google as well. Here a CI Date with a large full canopy is almost always fatter than one that has been over-trimmed, even if the trimming was held in check to nothing below horizontal. I wish we could record the growth of these via time lapsed photography, surely would be evident there as well. As you probably know/observe the stems of old palms are like a time line of sorts, revealing past freezes, transplants, etc. Kinda like digging thru archaic ruins.

Thx. I have been researching. Unfortunately most of the info is from So. Florida whose soil (sand) and/or available nutrients bear no similarity to the clay/loam soils of So. Louisiana, or California too for that matter. Here our soils hold nutrients very well, too well in some cases. Heavy rains at times do cause leaching of certain nutrients, but primarly of nitrogen. Other than that ph needs to be monitored so that those nutrients can be absorbed. Of course here, the issue is soils sometimes being too acidic and requiring the addition of lime to unlock their potential.

Well said Keith.

[Tala]

an even pH is best for these, our soil is mostly neutral but so sandy, we lose Mg and K quickly. With clay soils they should take right to it. If it were me I'd try to keep an even feed of N going, heavy feeders so something around 13 to 15%; then watch the fronds and they will tell you what the palm needs if anything. They all love wet feet as long as it is warm outside. Phoenix might the toughest palm genus there is, they grow in standing water or coastal rock, sand or muck, nothing fazes them. I just wish I could find an answer for graphiola...

added - would also recommend dolomite, great stuff for pH adjustments, doesn't burn and helps with Mg issues.

Edited August 7, 2008 by Tala