An interesting question today about plants aging and its effect on propagation. The bonsaiTALK thread can be found here:
Here is my reply:
There is a lot of confusion on this subject because woody trees don't age like we do. Higher animals have a system of cell division that ages each new cell (by using telemeres), thus creating a life span. I have heard that plant chromosomes also have telemeres, but they don't act in the same way, so that each new cell is a ... new cell, age zero. Some plant individuals are tens of thousands of years old, happily asexually propagating in an ever expanding shrubby circle. Asexually propagated grapevines can originate from an individual from Roman times.
So, when you asexually reproduce a woody tree from one year old wood, you have a new individual no matter how old the parent tree is. Trees don't die from 'old age', they die because of system failure, either environmental, or physiological. They develop hollow trunks, are subject to weather forces, disease, insects, etc. They often increase their bulk to an extent that cannot be supported. If their physiology allows easy adventitious bud formation or back budding, they may virtually start over after a catastrophe, but if not, they die. This is how those shrubby ring formation last millennia.
The monkey wrench in this system is that woody plants also have a characteristic called juvenility. A new sexually reproduced individual (seedling) will have a true age zero and will exhibit juvenile characteristics. These can be dramatic such as completely different leaf size and shape, and growth habit. Juveniles don't sexually reproduce, but in general, juvenile tissue is BETTER for asexual reproduction, probably because it is less differentiated. After a number of years, depending on the species, a seedling will mature and will be capable of flowering and fruiting. This can be as little a one year (Prunus tomentosum) to over twenty years (Quercus, Malus, Crataegus sp). Maturity is not well understood in woody plants, but is thought to be a hormonal process. Plants asexually reproduced from mature wood (cuttings) keep the maturity after losing it briefly, usually for a year or two.
So, if you start a cutting from a juvenile seedling plant, its age with regard to maturity is the age of the parent, and you will wait approximately the same amount of time as it takes the parent to reach maturity before seeing flowers. If you take cuttings from mature flowering wood, you will lose maturity for a year or two but should start seeing flowers after a year or two or three. There are also some environmental factors to consider in flowering. My crabapple cuttings flower in the cutting flats the next spring, very cute to see flowers on these tiny plants, but then they don't flower for two to four years after that. Seedling crabapples may not flower for twenty years or more, which is why I recommend against using seedling crabs for bonsai.
Juvenility can also be induced temporarily in mature plants in other ways. If you prune hard, many species will respond with juvenile growth, even changing back to juvenile foliage. We see this all the time in Junipers. After a year or two, this growth settles down to mature growth characteristics and is capable of flowering again. This is a method used in propagation to get juvenile wood from older trees to increase the strike rate of cuttings.