Indefinitely, if you grow it as a bonsai; best on the balcony rather than inside. But that will mean a lot of care and dedication, and almost certainly a complete soil change from the yucky stuff these are sold growing in, into some decent bonsai grower's mix. Ask on the Bonsai Forum for advice. Resin Here is a link that might be useful: Stone Pine bonsai example

Apical dominance in P. pinea? Come now, its character stems from its inability to establish apical dominance. The unique behavior of "umbrella pine", "pin parasol" is that within a cluster of leading and lateral buds at the end of any shoot, the laterals elongate more than the terminal buds. In other words, the terminal bud fails to establish dominance vis-a-vis the laterals. Take a look at any tree of the species. As soon as it is growing shoots of fascicled needles it will "globalize" in shape.

I found the one I had back in the mid 1990s to be pretty hardy; the erstwhile management of Forestfarm said their seed came from one in some frost hollow of western WA that had seen very low temperatures by PNW standards. Current management of Forestfarm knows nothing about this...too bad they didn't keep better notes. And, I think this reflect a general thing going on with Forestfarm. They will still have rare plants but not someone - an owner-operator-plant-lover - going through the tedious steps to obtain the "best of all possible rare plants". (always time for a little Panglossian optimism!) I really don't think they are particularly susceptible to fungus for any reason other than having been pumped full of nitrogen to get them into fast growth...when sold as the decidedly odd looking 'mini Christmas trees'. They grow in Texas around the dry line, which certainly can be humid! Years ago someone posted a picture of some big ones in San Antonio. And also of course one grew in North Carolina. I think, south of say Richmond, VA, they are just under planted, and north of it, likely to die back in the coldest of winters.

I wouldn't be concerned at all as pines are shedding their needles (as new growth pushes and every spring/summer). Scratch the bark at several places along a branch and if it's juicy green just under the bark, that's what's important. If you think it's healthly, help it along and remove those old needles (the tree will use more energy toward the new growth and provides better air circulation). Looks like a real nice tree on Google and from what I read. This might be of help, I don't know: "It is slow to lose the glaucous juvenile needles." Rushforth, Keith ÂConifers (1987); First published in the United States in 1987 by Facts On File, Inc., 460 Park Avenue South, New York, New York 10016; ISBN: 0-8160-1735-2. Dax