Bonsai Study Group Forum

Species Specific => White Pine Bonsai Discussion => Topic started by: augustine on November 05, 2012, 10:59 AM

Title: Pinus Strobiformis - SW White Pine
Post by: augustine on November 05, 2012, 10:59 AM
Hello to all,

I have a stock plant in a one gallon container. As to be expected Brent Walsten grew this pine wonderfully and it has all the necessary branches including sacrifices. I'd like to repot in the spring for the purpose of growing out. It will have to be a larger bonsai to compensate for the long needles. I realize that I have some years to go.

I live in the humid Chesapeake Bay region and have hot summers.

Does anyone have care/culture advice that includes appropriate candling and pruning techniques?

Thank you.

Best regards,

Pasadena, (Central) Maryland - Zone 7A
Title: Re: Pinus Strobiformis - SW White Pine
Post by: John Kirby on November 08, 2012, 07:49 AM
I had a few in Arkansas, in the ground, not in pots. Looks like you should treat them pretty much like a Japanese White Pine, quick draining soil, protect from intense heat. No "decandling" as in black pines, can break long candles/buds to control growth (remember it is the stimulated shorter regrowth that is kjey). John
From: (
Pinus strobiformis

Engelmann 1848
Common names

Mexican white pine, Chihuahuan white pine, southwestern white pine; pino blanco, pinabete, pino enano [Spanish].
Taxonomic notes

Syn: Pinus ayacahuite Ehrenberg var. brachyptera G.R. Shaw; P. ayacahuite var. reflexa (Engelmann) Voss; P. ayacahuite var. strobiformis (Engelmann) Lemmon (Kral 1993). See below.

This is a typical white pine in section Strobus, subsection strobi. This species is closely related to Pinus flexilis, with which it forms the hybrid Pinus flexilis var. reflexa (Farjon and Styles 1997).

In 2008, Michael Frankis described a new species, Pinus stylesii Frankis ex Businský, from Cerro Potosí and neighboring mountain ranges, chiefly in Nuevo León, Mexico. I believe that this taxon is derived from the hybridization of P. strobiformis and P. flexilis, and have reduced it to synonymy with Pinus flexilis var. reflexa, although in actuality it probably lies somewhere between typical P. flexilis var. reflexa and typical P. strobiformis. The full story is given on the P. flexilis page.

Trees to 15-24(30) m tall and 50-90 cm diameter, slender, straight; crown conic, becoming rounded to irregular. Bark smooth and silvery gray on young trees, aging to a dark grayish brown, furrowed, divided into rough rectangular plates. Branches spreading-ascending; twigs slender, pale red-brown, puberulous or glabrous, sometimes glaucous, aging gray or gray-brown, smooth. Buds ellipsoid, red-brown, ca. 1 cm, resinous. Needles 5 per fascicle, spreading to ascending-upcurved, persisting 3-5 years, 4-10 cm × 0.6-1 mm, straight, slightly twisted, pliant, dark green to blue-green, abaxial surface without evident stomatal lines, adaxial surfaces conspicuously whitened by narrow stomatal lines, margins sharp, razorlike and entire to finely serrulate, apex narrowly acute to short-subulate, resin canals 2-4, external; sheath 1.5-2 cm, shed early. Staminate cones cylindric, ca. 6-10 mm, pale yellow-brown. Ovulate cones maturing in 2 years, shedding seeds and falling soon thereafter, pendent, symmetric, lance-cylindric before opening, broadly lance-cylindric when open, 15-25 cm, creamy brown to light yellow-brown, stalks to 6 cm; apophyses somewhat thickened, strongly cross-keeled, tip reflexed; umbo terminal, low. Seeds ovoid; body 10-13 mm, red-brown, essentially wingless. 2n=24 (Little 1980, Perry 1991, Kral 1993).

US: Arizona, New Mexico, Texas; Mexico: Coahuila, Nuevo León, Sonora, Chihuahua, Sinaloa, Durango; at 1900-3000 m. Habitat dry rocky slopes in high mountains, or as a minor component in mixed conifer forests. In the United States such habitat occurs on isolated desert mountain ranges, and in Mexico it is widespread in both the Sierra Madre Occidental and Oriental. Within habitat, it mostly grows on moist, cool sites with associates such as P. hartwegii, and P. culminicola (Little 1980, Perry 1991, Kral 1993). See also Thompson et al. (1999).

Big tree

In the United States: diameter 150 cm, height 34 m, crown spread 19 m, located in Lincoln National Forest, NM (American Forests 1996). Since the great majority of the species' range is in Mexico, larger trees may be found there.

Tree VPK02 collected in the San Mateo Mountains of New Mexico by Henri Grissino-Mayer, J. Speer, and K. Morino had a crossdated age of 599 years (RMTRR 2006).

The seeds were eaten by natives of the southwest U.S. (Little 1980). It is locally (in Mexico) used for cabinetry, doors and window frames (Perry 1991).

In the United States, it can be found near the summits of the Chiricahua Mountains and probably in other high ranges of southern Arizona. In Mexico, Perry (1991) recommends the following locations:

    In mixed pine forests near 3,500 m elevation, at about 25.3333°N, 100.5000°W.
    At about 2,000 to 3,500 m elevation on Cerro Potosí, at about 24° 50' N, 100° 15' W. I have been to this site, where it grows with P. culminicola, P. hartwegii, and P. arizonica var. stormiae. See the Taxonomic Notes section of P. flexilis for remarks on P. strobiformis × flexilis hybrids that can be found here.
    Near Madera in Chihuahua, on north slopes at 2,000 to 3,500 m elevation, at about 29.2°N, 108.45°W. For this site you will need a local guide, a high-clearance vehicle, and should only go during the dry season.

As referenced in the photos at left, I have also found fine occurrences of it in the high passes on Mex-16 between Hermosillo and Chihuahua and in Durango about 20 km S of the town of El Salto. No guides or fancy vehicles needed for these sites!

White pine blister rust. (Cronartium ribicola), an introduced fungal disease, attacks this and certain other white pines (Little 1980).

This species is the primary hosts for the dwarf mistletoe Arceuthobium blumeri, which extends from southern Arizona south through Durango and east to Cerro Potosí in Nuevo León (Hawksworth and Wiens 1996).

Engelmann 1848. Sketch of the botany of Dr. Wislizenius' expedition. Appendix, pp. 87-115, to Wislizenus, F. A. Memoir of a Tour to Northern Mexico. Washington.
Title: Re: Pinus Strobiformis - SW White Pine
Post by: augustine on November 08, 2012, 02:56 PM

I was hoping you would reply. Also found the article that you kindly provided but unable to find anything that pertains to container culture.

One more question, would it be good to use a fungicide on a regular basis since my area is normally humid?

Thank you very much for your help.

Best regards,

Pasadena, (Central) Maryland - Zone 7A
Title: Re: Pinus Strobiformis - SW White Pine
Post by: John Kirby on November 08, 2012, 08:00 PM
You will likely need a rotation of fungicides, check with local Rutgers Cooperative extension, let me know if try don't have anything.

Treat likeva JWP in culture, should be just fine. God luck.
Title: Re: Pinus Strobiformis - SW White Pine
Post by: augustine on November 09, 2012, 09:37 AM
Dear John,

Thanks very much for your help and I will check about the fungicidal regimen. It is worth mentioning that the color is superb, very blue needles and creamy white bark. 

Best regards,


Pasadena, (Central) Maryland
Title: Re: Pinus Strobiformis - SW White Pine
Post by: bwaynef on November 09, 2012, 11:49 AM
Should any care be given to prevent the fungicide from coming in contact w/ the soil?
Title: Re: Pinus Strobiformis - SW White Pine
Post by: augustine on November 09, 2012, 03:47 PM
I normally try to keep fungicide out of the soil,  read that it is harmful to mychorrizae (spelling?).

Good point. Thank you.

Best regards,

Central MD - 7A
Title: Re: Pinus Strobiformis - SW White Pine
Post by: augustine on November 15, 2012, 02:45 PM
Hello John and All,

Went to Rutger's website and was directed to the Univ of MD Extension Service. My question was what, if any, fungicide(s) should be used as a preventative measure (for Pinus strobiformis). Rec'd the following response.

"Normally we recommend following the principles of Integrated Pest Management, i.e. discerning the problem before applying pesticides and using the least toxic but most effective product. In your situation, if fungal problems are inevitable, it would be helpful to familiarize yourself with which fungi you'll be targeting. We don't have that specific information here. We suggest you contact the Nat'l Arboretum which has an extensive bonsai collection at..."

I previously corresponded with Brent Walsten who echoed the same sentiment. On the other hand Julian Adams stated, in an article, that he sprays JWP with Daconil at certain times.

At this point I am inclined to want to apply Daconil according to the guidelines found on my Ortho Brand bottle (couple of times at budbreak, late summer, fall and after particularly rainy periods).

Open to other suggestions.

Thanks for your help.

Central Maryland