Candling is work, which is why none is done around here, any more.
The pot on the left, of the four, is a recent purchase. Well-made, and very heavy. I bought a number of these for dwarf conifers, but never got the conifers, so most stay empty.
The roots of Picea pungens, by the way, are hardy to -100F, if not much lower.
extreme western edge of Denver, Colorado; elevation 1705.6 meters, average annual precipitation 30cm; refuses to look at thermometer if it threatens to go below -17C
I've heard of them..... There isn't any place on this continent that's colder than my garage, by the way.
Here's another picture, also middling-quality, of an unnamed Pinus flexilis growing out of a trough, and not being as dwarf as it ought to be.
The American Conifer Society size classifications for dwarf plants can be misleading. A dwarf conifer can grow 3 inches a year. In 10 years it could be 30 inches bigger in all its dimensions. A 12 inch plant after 10 years could be 6' across and 31/2' tall. In my rock garden plantings I try to select a plant that grows less than an inch and preferably less than a half inch a year. Some growers are beginning to add annual growth rates in their descriptors. I have a 60 year old Hinoki that is 30 inches across and 24 inches tall with a trunk caliper of 3 inches...A perfect miniature tree with an annual growth rate of less than 1/4 inch. This plant has not been pruned or clipped in anyway. Its bonsai without all the art, fuss and work.
Such plants are becoming more available. They are expensive. To grow a softball size plant that will sell can take 10 years which is a large investment in time and space for a grower. There are, however, some readily available and not too costly miniature conifers. Two excellent Hinoki (Chamaecyparis obtusa) miniatures are 'Tsukumo' & 'Leprechaun'. Juniperus communis 'Blue Pygmy' is a bit larger at 1/2 per year. Picea abies 'Wichtel' does 1/4 inch a year.
Adding such miniature conifers to a rock garden adds an interesting and attractive contrast to an alpine display. Do not fertilize these miniatures. Plant in a lean, alpine grit (perhaps 10% organic matter).
Hinokis last about ten minutes here .....
A few more pictures. First, a Pinus flexilis from Taos. Then Picea pungens 'J. James'. (This is available in the trade.) Then two examples of Pinus monophylla grown from broom seed, showing different, weird rates of growth. Lastly, Pseudotsuga menziesii var. glauca, 87 (no name, just a number). This last suffered a bit from the May hailstorm. All from Jerry Morris.
My first attempt at the forum...I think I was just trying to address the entire conifer thread re "dwarfs" and trying to give some size selection guidelines. I agree that Hinokis are not hardy much below USDA zone 5. There are, however, nice miniatures in most Conifer Genera. Many are hardy to extreme low temperatures. Picea pungen miniatures are an especially good selection for containers and extreme cold as you indicated. P. pungens is not a good candidate for anything above USDA Zone 7 due to pests not being killed by lower temperatures. I've had no problems with P. pungens in Rochester, NY at USDA zone 6. Folks can't grow it in North Carolina at zone 7 due to "bagworm" infestation. Our winters are apparently just a bit too cold for bagworms.
Colorado at high elevation presents some difficulty in finding selections. Tsuga canadensis (hemlock) is hardy to USDA zone 2 but would certainly succumb to only 30cm of rain a year and your low winter humidity. Jerrry Morris also did some selections of Pinus aristata. (I have one called 'Silver Bee' that has grown 4 " in ten years.)
I was surprised to see your Pseudotsuga . I lost a beautiful 8' 'Emerald Twister' last winter due to the "Polar Vortex". The tree just "freeze dried" in the relentless 30mph winds, 10 degree F. temperatures, and bright sunshine. It would seem hardy enough but my conifer buddies tell me that it is native to a maritime climate with cold but moister conditions and what we had last winter was just too dry for it.
I think all of this shows that many factors (some not so obvious) can determine the success of a conifer. However, the quality that a miniature conifer can bring to a rock garden is worth a little experimenting.
I definitely agree with the last sentence. They also make the garden a lot more interesting in winter.
DBG has a number of chamaecyparis but, being farther east, they are protected from the winds coming off the Continental Divide, and they're planted in areas where they're also protected from our hot winter sun.
The pseudotsuga pictured is one of Jerry's; the native subspecies, not the one from farther west. I did lose a beautiful specimen of 'Vail' last winter, but that was after I brilliantly decided to transplant it. Also have a dwarf--dwarfish--Pinus aristata with no name.
Welcome to the forum, 1000176. I have to say, I've never said that to a bunch of number digits before....
You're definitely right that "dwarf" has always been a relative term, and I'll bet those really slow growers of Bob's would grow a bit faster in my climate with more rainfall (if they like it). Heck, the dwarf apples that are available here in Minnesota grow half to two-thirds of normal, so that means 20+ feet. I don't have any miniature confers anymore, since I killed my two Tsuga from neglect. But I do have some dwarfs:
About 15 years old, Larix decidua. Dwarfed by the pot size. Gotta love that bark! A Cerastium alpinum volunteered in the pot.
Picea abies 'Parsonii', 30 years old. In the upper left, a bit of species Thuja koraiensis.
Picea omorika 'Triblitzch', 10 years.
Absent in the trade now is the original Chamaecyparis pisifera 'Filifera Nana'. It is still showing last winter's dieback: the first winterburn ever in its 18 years of life in full sun. The strong March sun, especially after a heavy snowfall as in this case, is the worst thing that can happen to a conifer here.
Rick Rodich zone 4a. Annual precipitation ~24 inches
near Minneapolis, Minnesota, USA