Most of the orchards around here (peach, plum, nectarine, almond or orange) put plants into an orchard at about 1 foot to 18 inches high. It takes several years to mature enough to produce fruit. Interestingly, for the stone fruits and oranges, the trunk is actually a different plant, and the desired fruit branches are grafted onto the mature stock. So orange trees are actually sour lime stock (better heat and disease resistance) with orange branches grafted in. In the first year of production, many of the stone fruit growers leave just one branch of the original tree growing and graft in the remaining branches. I guess the single branch supports the tree long enough for the other branches to catch up. The trees sure do look odd when they are cut up like that.
Interestingly, for the stone fruits and oranges, the trunk is actually a different plant, and the desired fruit branches are grafted onto the mature stock.<<<
Many plants are grafted, fruit trees and roses, if they are to be true to the named variety.
That is why planting fruit tree seeds is so much fun, at the least you get a pretty plant from citrus seeds, and who knows, maybe you will have th ‘one’ that someone thinks is a good one.
Orchids to be the named variety, have to be a part of the actual plant, you cannot graft them.
Some shrubs and trees can be propagated by scraping the bark and putting it in a growing medium, while still attached to the original plant, until it roots........a world of study.
I promise that you will never learn all there is to know about gardening, science plays a large part in it.
Strange as it is, the new ‘fads’ in gardening, are the ancient ways of growing, there is little that is brand new.........except in electronics.