If you can't compare their shoots, buds and leaves to other stock known to be correct then you may even have to wait for cones. Note also that there is a specific Conifers forum here.

jean, Yes, I have carefully sprayed Round-up around the bottom of the trees where I have them mulched with pine straw, so you may be on to something there. Thanks for the heads-up. ken, I had to chuckle at your post. It seemed a little "snarky". :) forgive me if I'm wrong. Anyway, there must be plenty of people "wasting" money on evergreen fertilizer, since nurseries regularly sell it. Besides, I was informed (on this site) of a condition called "little leaf" that one of my loblolly pines had (Pinus taeda), and the solution was fertilization. Sure enough, it worked. No, this variety is not supposed to get yellow needle tips. They are called Sonderegger pines and are crosses between Longleaf (palustris) and Loblolly. Here is what mine look like right now.. I realize my camera didn't focus very well on the next two pics, but hopefully it's enough info to help Some additional info: We had a colder than average winter, with a few nights in the single digits. The pines have been in the ground for 2 years now. Overall, I've been slightly disappointed with the pines. I expected much more vigorous growth, and much longer needles than these pines have.

Sonderegger pines are natural hybrids of loblolly X longleaf frequently found in Louisiana and east Texas. As a natural hybrid population, the trees are not necessarily intermediate between the parent species in any particular characters, because the populations have crossed and backcrossed for many generations, and "hybrid breakdown" has occurred. Thus the trees from this population show a lot of variability.

You know, on second thought, it's not so dramatic as I made it out to be. This tree is on a slight hillside ending in the lowest spot of my property, which according to google earth has about 25 ft. of elevation change from highest to lowest. Because of that I'm usually standing 2-3' higher than the trunk when viewing it. It creates an illusion it is shorter than it is. It is probably closer to 15'-18'. It is recovering a leader, the question is just why it is going about it so slowly. Here's a pic taken from a ladder on the other side to balance things out. To the right is the perfect cone shaped top of my Abies firma now hitting 30'. At any rate, it's fate is still sealed. I'm going to try to ground layer it starting this weekend. That process could take up to 2 years, but once I have well rooted replacements, it will get the chop and be ground up in my tree guy's fearsome gigantic Vermeer chipper to make what I'm sure will be some nice smelling mulch. There are just too many large trees in this area - there are others I didn't even mention earlier. A clone will be planted in a less critical part of the garden where the 'Chapel Hill' is growing well. This is the 'prestige woodland' area with my best rhododendrons, BLEs, etc. so I can't really afford plants that are in some way not performing here. If 'Soquel' continues to pull a 'wide Putin' in the new location, it will be deaccessioned as in some way unsuitable. Nobody wants a redwood tree to be short and squat LOL. (which reminds me when I removed a branch of a huge maple to the right of this view, all the rhodies now behind this Sequoia flowered better.) Here's a closer pic of the Abies pindrow just to show how it's coming along. Along with the A. firma there's only been one year its leader was so damaged by a spring freeze I had to restore it to a single. This was about 2' when planted, the firma was 6'.