Yeah, I normally tosse them out after a year; The second winter is usually the end of them if they have not rooted.
For me it is more to know when I should be giving up on my pine cuttings. Still halfway green, lokoing sickly by now though
My experience also. I leave them while they still look healthy but after they look sick there is little hope.
I understand why you would want to use cuttings if you want a clone of interesting parent material, or can't locate seeds, but we're talking about a process that yields results much less quickly than growing from seed with a lower success rate(?)
With many deciduous, cuttings will gain you a year or more on the propagation timeline. I'm not arguing for or against, I am simply pointing out the obvious - and the main reason why conifers are almost exclusively propagated via grafting.
Seedlings are definitely a faster and better option but our government has declared all pine material prohibited because there are some pests that we don't already have that can travel on seed. That has made pine seed really hard to get down here meaning grafting or cuttings are alternatives. You are already aware that bonsai growers now have an unreasonable fear of anything grafted so any grafted pines are hard to sell no matter how good the grafts are.
Some of my cuttings can grow reasonably quick and compete with seedlings after a couple of years.
I have now planted a couple of JBP, some JRP and a JWP as future seed sources. I actually harvested around 100 JBP seed last summer but cutting technology is still worth pursuing if only to propagate selected clones of any of our bonsai pines instead of relying on grafting.
My experience is that most deciduous from cuttings are not much quicker than seedlings. There are a few species that will strike from larger cuttings that may save some time but not all. Many conifers are also very slow from seed. Does anyone grow junipers from seed in preference to cuttings? Cuttings are way faster for many conifers.
They use a well grown out fast growing root stock and graft in branches or small trunks of the desired foliage I’m assuming? Trunk would be from the base stock?
Conifer grafting has not yet evolved to the stage of having selected root stocks. JBP cultivars are grafted onto seedling JBP. White pine is also grafted onto JBP seedlings. Grafts can be made at any position on the stock. For bonsai purposes really low grafts are favored so the root stock really only forms the roots and maybe very base of the future trunk. Most of the root stock and the graft union is hidden in the transition from roots to trunk and the main part of the trunk is from the graft.
Junipers are commonly 'top worked' where grafts are inserted higher on the trunk or on the branches to preserve an advanced juniper trunk. In that case the trunk is from the original tree while branches and foliage is from the grafted variety.
There are some fast growing juniper species that can be used to develop trunks relatively quick then grafted to a better species for improved foliage. The grafts also tend to grow quicker when grafted onto such a stock so development of branches is also faster than the same juniper growing on its own roots.