How could my Pomegranate still alive?

[sapote]

 :blank:As you might recall that when I installed the paver yard 3 years ago, I ended up raising the soil level around the big old tree higher – about 3” or 76mm higher – and this was killing the tree. The tree started having poor health with dropping immature fruits and then yellow leaves in middle of Summer instead of Autumn. Many branches started dying back. To save the tree I cut back all branches but a small one  to a 10 ft trunk and remove the top 3” of soil. I noticed the bark around the trunk at soil level were dead by fungus. The next Spring that small branch carried some flowers and leaves, but then all died back slowly down to the main trunk. The lower huge trunk – around 24” diameter – sent out a few small shoots – a hopeful sign. I continued paying extra attention to care for the old tree – must be over 60 years old I think – but I noticed the bark near soil level were all dried, cracked and peeled. One would think the upper trunk would be dead after it spent up its reserved energy. But this years those small shoots have become the size of a thumb and there are two healthy looking fruits. When I first noticed the red flowers few months ago, I picked them off trying to save the tree's energy, but just like mango, the tree sent out more flowers in no time. I left them alone and I learned that those few with a little more round (as oppose to skinny or bony)  below the waist were female flowers and became fruits. So how one explains why the tree survives with the dead bark around the trunk? I had carefully try to find a small trace of living tissues in the dried bark with my finger nail scratching  around the trunk but found none. I even peeled off some areas and all I found was a shiny dark brown hard wood under it. I’m pushing three 24” tall seedlings planted near the old trunk in hope that I be able to graft them into the living upper trunk skin one day. But where is the old tree energy came from to keep it going?

Sapote

[fyliu]

It probably grew roots above where the trunk meets the soil?

[greenman62]

If the trunk is 2ft in diameter
and only the outer bark is missing, there should be plenty of
energy still coming from the roots. im sure the root system is massive.

it depends on the type of tree
but often, the xylem and phloem (water and sugar transport system)
are more toward the middle of the trunk
the outer, and sometimes inner (pith) are more structural.

[sapote]

It probably grew roots above where the trunk meets the soil?

From the soil level to 12" higher are all dried dead bark and dried wood under neat, so no new roots around there I can see.

[sapote]

"If the trunk is 2ft in diameter
and only the outer bark is missing, there should be plenty of
energy still coming from the roots. im sure the root system is massive."

Not only the bark is dried and dead, but the wood under the bark are also dried and cracked. So there is no living layer to transport water and sugar at this surface.

"it depends on the type of tree
but often, the xylem and phloem (water and sugar transport system)
are more toward the middle of the trunk"

I'm sure I can agree with this. All information I find say the xylem and phloem are just under the bark. This is how airlayer works: we peel off the bark and xylem which stops the sugar from the leaves to the roots, but we left the phloem intact so it can transport water from the roots to the leaves, and the increased sugar in the branch causes it to send out root for using the extra sugar; if not the upper branch with extra sugar will explode with a big bang -- I make this up

[LivingParadise]

This tree clearly has a tremendous will to live. I would accept it with gratitude, and stop injuring it to try to figure out how! You might accidentally kill it cutting around in there. Just enjoy that despite all odds, this tree continues to want to live, and to sacrifice to put out fruit. Sometimes we have people who survive medical traumas in ways we cannot possibly explain biologically... nerve endings seemingly generating from nothing, or any one of countless scenarios where the person logically should be dead, but isn't. Sometimes the best thing to do is just enjoy it, and don't perform exploratory surgery to the point that you kill the person trying to answer the question. When the tree is really dead, you may be able to dig up the stump and figure it out. There might be a portion still alive in the heart of all that dead wood, connecting to a root or two still alive in the center of all the dead roots, far enough underneath that you can't easily get to them. The tree may not last forever, but it's amazing that it lasted this long.

It is a happy accident to have this problem - a tree that lives for no reason - rather than the opposite: a tree that has died for no apparent reason. Enjoy the fruit!

[sapote]

"When the tree is really dead, you may be able to dig up the stump and figure it out. There might be a portion still alive in the heart of all that dead wood, connecting to a root or two still alive in the center of all the dead roots"

I felt very bad after I realized that it was dying because of the 3" higher soil I filled into the hole. I was aware of higher soil level problem but I thought Pomegranate could take it because the plant can be propagated by cutting or covering a bent down branch with soil and it will root.   I only explored gently with finger nail scratching, although I must admit I didn't  dip the nail into alcohol first

Seriously we all want to know how things work. All I have learned is that trees cannot survive with only the wood without living bark. I will post some photos.

[greenman62]

if not the upper branch with extra sugar will explode with a big bang

LOL
i will have to watch out for that next time i air-layer

Not only the bark is dried and dead, but the wood under the bark are also dried and cracked.
 So there is no living layer to transport water and sugar at this surface.

i didnt know how deep you probed into it.
i was guessing that there must be some amount of water going back up
to support the growth on top.
i would think even a few cells wide (left alive)  would work, since it can work 24/7
but, if that is the case, i dont know if it can get bigger ?
once the upper growth is so large, the part left alive can not support it...

i dont know if a POM can create new growth inside a dead trunk
it sounds doubtfull to me.

Ive never had a large POM, but, i have several that are 3-4 ft tall
im kinda surprised it didnt send up new growth from the roots...
they often send up growth from the root, or maybe its just the base of the trunk
i hadnt looked that closely.
part of me thinks you should add N rich fertilizer
the other part says , NO, it would make it grow too fast and cause problems.
maybe a root-growth hormone ?

I had planted my largest POM in a spot i now realize was too low,
and wish i could add 3 inches of soil, im getting ready to buy some anyway.
i guess its a no-go... LOL

[fyliu]

Sapote, you got xylem and phloem reversed. The way I was told to remember was the nutrients from the leaves "phlo" downward. ...unless I'm the one who's mistaken. In that case, someone correct me.

[sapote]

Sapote, you got xylem and phloem reversed. The way I was told to remember was the nutrients from the leaves "phlo" downward. ...unless I'm the one who's mistaken. In that case, someone correct me.

I might, but the point is that both these layers are relatively closer to the bark, not the heart of the wood.

[sapote]

"im kinda surprised it didnt send up new growth from the roots...
they often send up growth from the root, or maybe its just the base of the trunk"

This is generally correct for Pom. In fact before this happened, every year I had to cut off those ground level shoots to clear up the trunk. The tree sent out around 10 shoots around the base. But now there are no living root around the base that I can find, and you can even see in the photo shorten shoots had dried just as the base.

[sapote]

Here are the photo of the used to be a tall handsome tree which provided us about 50 huge sweet fruits to be harvested right on Thanksgiving day. I found it's the best time to pick a fully ripen juicy Pom in Southern Cal climate. It was tall with broader shade over the outdoor dinning table.

The 3 small seedlings are for grafting to the main trunk in the future when they reached up to the upper living trunk.




Those one year old new shoots look very healthy, even carry couple fruits too. My "Mrs. Jumpy" wanted to be on the pic too.



The dead dried cracked bark and wood around the base










and even the carpenter bee agreed that this trunk is a piece of dead wood:

 

[sapote]

So 4 years had passed and  my used to be beautiful gigantic pomegranate didn’t recover as I had hoped – only three ¾ inches branches left with a few fruits on them and slowly died back. I decided to dig it out and plant a young sweet heart lychee in place. The old tree must be over 60 years old.  Dug and removed 3 feet deep of soil, I found all of the main roots – big as elephant tusks – were dried up and rooted. It’s so bizarre that I checked around the trunk and there was no single living roots but the tree continued living and had fruits!!! I used an ax to chop the dried hard roots and pulled the tree out from the 3 feet hole. The thing must weight around 4 or 5 hundreds pounds. No way that one person could pull this out alone, so I just rocked it to one side then filled in some soil to the lifted side, then rocked it to the other side and filled in the lifted side with soil. I repeated slowly until the whole thing was lifted up high enough to roll it out of the hole. With it outside the hole, I could see at the center, surrounded by all those dried and rotted big root, was a group of young small root hair -- pointed to with a small metal rod -- that kept the tree alive. I really don’t know how these new small roots connected to the three small living branches while all the barks around the entire trunk were dead. (The garden hose laid on the tree is where the soil top level used to be, just to show how deep the deep system is.)

I had air-layered a fine lychee and planted one before, but after 5 or 6 years it only grew to 2 feet tall and gave 3 delicious fruits, then died back slowly and gone. I have been doing well with mango, longan,  but found growing lychee is such a challenge. This time I will continue to add kitchen green and fruit trash to the top soil around the new tree and I think it likes this environment better -- it sure looks like it's in southern China forest floor!!