Picea pungens / Colorado spruce
Picea pungens, as described in 1879 by Georg Engelmann (1809–1884), in The Gardeners' Chronicle, new series 11, is commonly known as Blue spruce, Colorado spruce, white spruce, silver spruce, or Parry spruce; as well as épinette bleue in French Canadian; and as pino real in Spanish. The species name described this conifer's exceptionally spiny needles. It is the state tree of Colorado.
Description. Colorado spruce is an evergreen coniferous species of tree that grows to mature heights of 165 feet (50 m) tall with a trunk 5 feet (150 cm) in diameter, measured at breast height.
- Crown is broadly conic in shape.
- Bark is gray-brown in color.
- Branches grow slightly to strongly drooping; non-pendant twigs are stout and yellow-brown in color, usually glabrous.
- Foliar buds are dark orange-brown in color, measuring 0.24 to 0.48 inch (6 - 12 mm) in size, with a rounded to acute apex.
- Leaves are needle-like, measuring 0.6 to 1.2 inches (1.6 - 3 cm) long, 4-angled in cross section, rigid, Blue-green in color, bearing stomata on all surfaces, with a spine-tipped apex.
- Pollen cones are red in color, growing in whorls of 3 to 5 at the proximal end of new shoots, primarily borne in upper crown.
- Seed cones are also borne in the tree's upper crown. They are pale green or red when fresh, ripening to pale buff brown, 2 to 5 inches (5 -12 cm) long with elliptic to diamond-shaped scales, widest below middle. Seed cones mature in August; seed shed is from September into winter.
Distribution. This species is native to USA — Idaho, Wyoming, Utah, Colorado, New Mexico and Arizona, growing in the montane zone at elevations varying from 5,800 to 8,800 feet (1,830 - 2,740 m) above sea level in the northern range of the species, and from 6,800 to 9,800 feet (2,130 - 3,050 m) in southern areas. It prefers conditions where the climate is cool and summer-wet, with mean winter minimum temperatures of 12 to 48°F (-11.1 - 8.9°C) and mean summer maximum temperatures of 70 to 72° F (21.1 - 22.2°C). Average annual precipitation varies from 18 to 24 inches (460 - 610 mm), with half of the annual precipitation falling during the growing season. It is the most drought-tolerant species of Picea in North America.
Hardy to USDA Zone 3 (cold hardiness limit between -40 and -30° (-39.9° and -34.4°C).
Attribution from: Ronald J. Taylor, Sections on Picea and Tsuga. Flora of North America Editorial Committee (editors); Flora of North America North of Mexico, Vol. 2; ©1993, Oxford University Press.
Photo by Panayoti Kelaidis
Photo by US FWS photo, public domain
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Photo by Blake Willson, courtesy of TreeLib.ca
Comments
We have three blue spruces in our yard, all about twenty years old, and all are gradually losing their needles from the bottom up. A tree person told me that there was nothing that could be done for them. This started about three years ago. We have had them sprayed for bag worms, so this is not the problem. Help!
Pat so sorry somehow we missed this query! Blue spruce doesn't do well out of its native range (Rocky Mountains) although it generally performs pretty well in places with dry summers with cool nights. This sounds like needle cast disease. You can read about it. Where are you?
Sara,
You mention performing better with dry summers. It seems one thing that distinguishes the Rocky Mountains from the Sierras and other west coast ranges is they get considerable summer rain. Yes, it is still low humidity and cool/cold nights, but regular summer rain. Maybe the cold night time temperatures are more of a factor?
Good point, Dan. I have been reading more about this tree over the last day or so. I think that you may well be correct. I think maybe the reason that it does well here is that it is more drought-tolerant than many other conifers. I do irrigate, and our nights are cool and our air dry, which is similar to the mountain climate.
I am interested in buying normal 8 spruce blue evergreen trees to be planted around my home in Zephyrhills located at area 30 miles NE of Tampa, Florida. I prefer those that would grow more than 20 ft. like I saw one blue spruce tree of 15 ft in few blocks away from my home…can it be done??? Usually comfortable dry during daytime (80F’s maximum) and high humidity cool at night (35F minimum ) from fall thru spring . However here during summer climate temp rise to hot humidity to 95-97 max at daytime and lower to 79 minimum at night. Wonder if I can plant this kind similar to what I saw at my neighbor’s front yard. I like it and want the same I know that theirs was trimmed to 12 ft when it actually would be 40 ft bars on diameter of end of branch to the another end of branch in opposite direction.
this species is evolved to thrive in semi-arid steppe environment. High humidity invites all sorts of fungal problems and lack of freezing in winter would be that plants will be deprived of their required winter dormancy.
In general, spruce are a terrible choice for semi-tropical and tropical climates.
In other words, a Blue Spruce would NOT do well in the PNW, near the Olympic Mountain range? I assume because it's too "damp"?
that's correct. It's actually our extended, wet springs they don't like. They do really well for a while, then the fungal issues kick in and turn them ugly pretty fast.