I just finished reading Larry Jackel's book "Ponderosa Pines as Bonsai" I highly recommend it , if you're going to keep Ponderosa. well worth the money. Pick up a copy from Andy Smith at Golden Arrow Bonsai, you won't be sorry. It even tells you how to cut the needles if your going to show the tree.
Ciao,
Harry
I need to get this book too.....I do know of Larrys method and I all would say is that I have seen it weaken trees. Even Boon won't use it because of that. I have used in on a few branches with good luck, but I have never done the whole tree. Brother in law Rich used it and got a ton of back buds, but then the tree needed a few years "off" to recoup.
Walter gets candle extension on his ponderosa like JBP, which is unheard of in the states. I have followed Walters advice for the most part with my Ponderosa's.
Ponderosa set buds in the fall, so fertalize heavier in late summer through fall to aide in bud setting production. I do fertalize from march through the summer too, but not as often as I would say a JBP or a Maple.
When developing a tree during early stages, feed and water like normal, but when you are in a refinement stage (close to show) then water and feed less. In my cilmate I will fertalize maybe once a month with a quick shot (not a soak) and then water the roots well once a week or so but spraying foliage daily which gets some water to the roots. This will help to keep needles in check.
You can also cut the needles too. I have done it in late winter with very little sign of them being cut. Cut them in the summer and you will have much more signs.
There is more than one way to get them to respond like we want them too, Larrys is one, Walters is another and soon there will be another way. The good thing about ponderosa is that most of them are larger trees so the needles fit the scale of the trees and don't need much reduction if any at all. Not all needles on ponderosa are long either. Many trees are collected with short nice needles and they are growing next to a tree with long needles. I have trees with 1" or less needles and they were collected that way. Its all about conditions.
That is just a real brief thought on the question.....
Ponderosa, the king of American bonsai~~~!!!!!!!!!!!!!!!