i am not an expert, but i dont believe the node count works that way. i think that onces its hit on the tree, it goes for the whole tree. this is what i remember being disccused somewhere. i have also heard that people who graft onto a tree with a differnt variety count can start producing fruit from the new variety if they tree they grafted on to had allready hit is node count.

but i could be wrong as i dont have any personal experience regarding that...

Hi nero,

I know you can graft mature scion wood onto a trifoliate seedling (maybe two years old?) and it will bloom shortly. This is done in the nursery trade. You don't have to wait for the rootstock to hit its own 'node count' (for if that were true, it would add years before the grafted tree would bear, and also add $$$ to the cost of the tree). The age of the rootstock should have no bearing on the performance of the scion (at least in regard to blooming), as far as I know. As long as the rootstock is old enough to have bark slip in order to get a good graft union, it should work fine.

As far as the 'entire-tree-node-count theory', I hope Dr. Manners will see this and comment.

well that is an interesting thought as i have never looked at it that way...i am eager to see his responce...

Dave,
I think you have it right if I'm reading your question correctly. You start with the seed as node zero, and count up from there. When the plant makes its first side branch, say at node 14, the next node above that on the main trunk will be 15, AND the first node on the new side branch will ALSO be 15. So on a big old tree, there may be hundreds of node 4762. Each node "knows" and "remembers" its own number. If you bud/graft node 4762 into the base of a rootstock seedling, you don't change the seedling's node count at all, but when the scion grows out, it makes 4763, 4764, etc. on the scion stem.

The result of all this is that a seedling must grow rather far away from the seed to flower, hence the problem with flowering a seedling in the house. If you prune it back, you remove some node numbers. If you pruned to #43, throwing away nodes up to 100, when the houseplant resumes growth, it resumes at 44, NOT 101. So a constantly pruned house plant may never flower. And even an ancient seedling tree which has been flowering and bearing fruit for 100 years, if cut down and the stump resprouts, it will be juvenile again. The nodes never forget their numbers.

But this is also why the technique of air layering or rooting a cutting from the top of a seedling houseplant, and replacing the original plant with the new propagation is a good way to get flowers and fruit, eventually. If you take a cutting that contains nodes 56, 57, 58, and 59, root it, and make a new potted plant of it, it will resume growth at 60. So you've done away with several feet of stem length in the process of getting to the minimum needed node number for flowering.

Dr. Manners thanks for the thorough answer. That's how I understood it to work.

what about regarding the part of lower nodes not producing flowers/fruit. i guess my question is that if lets say node 100 on the top part of the tree is producing flowers, cant node 15 on the first branch produce as well?

Nero,
No, never. That's why century-old seedling trees continue to produce fruit in the top of the tree, way out of reach unless you have a ladder, but never on the lower branches.

but this is only from citrus grown from seed correct? grafted ones would not attribute this and could grow from lower branches?

nero,

Technically, it depends on where the graft came from. But typically grafts are taken from mature wood (capable of blooming). It would sort of defeat the purpose to graft from juvenile wood. A graft, let's say Valencia, might come from a tree that was grafted from another tree in Florida, that was grafted from another tree in Spain, and so on. So the 'node count' of a graft could theoretically be at a node count of, who knows?, maybe 100,000 nodes, depending on how many generations old it is and how many times it's been propagated. Anyway, if the scion would is mature, any side branches would certainly be capable of blooming and bearing. Hope this answers your question.

Ok, according to Doctor Manners a seedling citrus tree matures branch by branch by branch. Now another question relating to his statement "there may be hundreds of node 4762." On citrus trees generally when the main trunk produces a new lateral branch, the new lateral branches are somewhat above, higher than the older previous branch. Because the new branch is higher on the main trunk the node counts on the new branch should start with a number grater than the branch below. This leads to my question, how then can there by hundreds of node numbered 4762? Before I wrote this post, I looked at my citrus trees and in every case the branches were always higher the previous branch. Thank you.

Let's say that the magic number for growth to mature is at node 5000.

If I understand your question then, in your scenario suppose a new side branch begins at node 4800 and the main trunk tops out at node 4900. Quite probably then the side branch will exceed node 5000 and begin to bear, whereas the main trunk won't. Any number of side shoots will develop well beyond node 5000 and will be capable of blooming. In this diagram, even though the tip of the main trunk can't bear, there are now nine other 'node #5000s' where growth will be capable of blooming (they have exceeded the node count of the main trunk). At least that's my understanding. Cheers!
{{gwi:570005}}

Dave thank you for the above explanation, but that does not answer my question. Perhaps I did not explain my question properly, however, I think I just this minute worked out the answer in my head. Doctor Manners said, -- "next node above that on the main trunk will be 15, AND the first node on the new side branch will ALSO be 15." Therefore, the second node on the new side branch will be 16 and up and up for that branch. OK, when the tree again grows a new side lateral branch, above branch node number 15, does the first node number on the second new branch begin with the node number 16 and go up from there for that branch? Later when still another lateral branch is produced, does the 3rd new branch start with node number 17? If so then I can understand why the tree can have hundreds of nodes which can have the number of 4763.

ok what about when a grafted tree blooms when it is small and the branches are not very long. will it continue to bloom at those lower branch locations even when it is quite old in essence having the whole tree producing fruit, the lower and top end? or does the node count change to higher requirements as the tree gets larger for it to produce fruit at?

Nero, yes on a grafted tree the lower branches will continue to bloom and fruit as it ages. In fact the bottom of a grafted citrus tree (called the skirt) produces well. Once a particular node is set it is set

Yes, that is what Dr. Manners explained to me. Sorry if I was unclear. If a new lateral shoots out at main branch node #15, its next leaf will be #16. At this point both the main trunk and the new branch have a node 16. Later on when another lateral shoots out of the main branch above the first one, lets say at node 20, its first leaf will be #21. The third lateral, depending on where it originates, will begin its count at that higher level. Then lets say a lateral comes out near the soil level for some reason, it begins its count at some incredibly low number like #3 or #4 or similar. It will likely exhibit very juvenile, thorny growth and may never bear.

Don't know if this drawing helps. This assumes that at node #470, growth becomes capable of blooming:

{{gwi:570006}}

ok what about when a grafted tree blooms when it is small and the branches are not very long. will it continue to bloom at those lower branch locations even when it is quite old in essence having the whole tree producing fruit, the lower and top end? or does the node count change to higher requirements as the tree gets larger for it to produce fruit at?

nero,

A grafted tree is created with a mature scion. The scion never forgets its node number....could be something like, who knows?, 100,000 or a gazillion, depending on where it came from. Any branches that shoot from it will begin their node count at the scion's count, if that makes sense. ANY branches that come from it will be capable of bearing no matter how large or small the tree. To my knowledge branches cannot revert back to juvenile once their mature.

Kind of like have you ever seen English ivy growing up a tree, then all of a sudden it matures into a more shrubby-like thing? It grows branches and the leaf shape changes. If you take cuttings of this mature growth, it will retain its shrubby character and not revert back to its juvenile viney character.

so when nodes are removed, lets say on your diagram, 458 on the side branch, it wouldnt restart becuase there is a 458 on the main branch...

If the side branch was trimmed back to just above node 458, likely a shoot will emerge at node 458 just under the cut. When it begins to grow, it's first leaf will be a node #459. If you trimmed the entire tree back down to just above node #450, it will resume growth starting with #450. This is why, as Dr. Manners said, if you trim down an ancient tree that's been bearing for many year, to within a few feet of the ground, the shoots that sprout from the stump will have to resume growth at those lower node numbers and will be thorny and juvenile.

So one way to get a smaller bearing plant from a seedling would be to grow it as tall as you can; root a cutting of the top; grow it tall again, take another cutting from the top, and so on. Eventually it will reach its node count. Problem is, it can take many, many years. Is it worth it?; probably not if it's hard to root, except just as an interesting experiment!

This is a way you can eventually keep a citrus grown from seed smaller and eventually have it bloom

{{gwi:570007}}

that is interesting and i must say your diagrams are great. I do have a few plants growing from seed just for fun so atleast i know about this now.

What about this question. If we assume all trees that are grafted came from mature trees, why do some take longer to flower and fruit then others? I have had one that i have had over a year and it has never flowerd. Every other tree i have all flower around the same time...

There are a lot of factors that might prevent a plant from flowering. These would include the season, root problems, wild temperature fluctuations, failure to acclimatize to a new environment, problems in watering, not enough light, etc, etc. One thing I've noticed though, some of my plants have been kicked into bloom after a prolonged dry spell.

I'm pretty much in agreement with all of the above. Sorry, I've been offline for several days.

As for why a newly grafted tree, even with a very mature scion, would skip a few years before coming back into bearing -- the great vigor provided by the rootstock can force the scion back into a sort of false juvenility. In citrus it tends not to last long, although 'Minneole' on 'Cleopatra' roots can take 8-10 year to really get producing. Up until then it may produce just a few flowers and fruit, on a fairly large tree. On some other fruits (e.g., 'Northern Spy' apple or 'Stuart' pecan), the false juvenility may be 15-30 years. In the case of apples, you solve the problem by grafting to a dwarfing rootstock. With pecans, you either plant a different variety, or you plant with dreams for your grandchildren.