Plant Data
Sheet
Pinus ponderosa, ponderosa pine
Range
Climate, elevation
Sea level - 3050 meters. Average
annual temperature: 5-10 C. Average
July/ August temperature: 17-21 C.
Annual extremes: -40 to 43 C.
Average annual precipitation in dryer parts of range: 355-760 mm, much
as snow. Average annual precipitation in
wettest parts of range: 1750 mm.
Local occurrence
In
Habitat preferences
Warm sunny places that are dry in the summer. Although sites are dry, there is available
soil moisture. Can tolerate severe
winters and can tolerate wet soil in the winter.
Plant strategy
type/successional stage
Can
be climax species or serial species. Climax species at the lower limits of coniferous forests. Serial species at higher
elevation more mesic forests.
Fire kills seedlings but not older trees. Fire suppression is creating an understory of
Doug-fir and true fir.
Associated species
In
the NW: Doug-fir, lodgepole pine, grand fir, western larch, Arctostaphylos, Ceanothus, Spirea,
snowberry, Oregon grape, Poa spp., Festuca spp.
May be collected as: (seed,
layered, divisions, etc.)
Seed. Doesn't
naturally reproduce vegetatively.
Difficult to propagate from cuttings. Can be propagated by rooting and grafting but
success decreases when scions taken from trees more than 5 years old.
Collection restrictions or
guidelines
Collect
cones as soon as they are ripe. This is
when the color changes from yellow-green to russet brown, September and
October. Widely spaced dominant trees
have the most seeds per cone. Begins to
produce seed at 7 years and continues to 350 years. The most viable seeds come from trees 60-160
years old. No regular interval observed
in heavy cone crops, can be up to every eight years. 31-70 seeds per cone.
Seed germination
Fresh
seeds have no dormancy and will germinate immediately upon collection.
Seed life
Up to18 years. Pines have highly variable
germination after storage.
Recommended seed storage
conditions
Dry
to 5-10% moisture content and store at 2-5 C.
Remove from storage one week before cold stratification.
Propagation recommendations
Plant
seeds in the fall after collection or in the spring after cold
stratification. If seeds have been
stored, they require 30-60 days cold stratification.
Soil or medium requirements
No
inoculum necessary.
Installation form
Seeds or container grown plants from seed.
Recommended planting density
380 seeds per square meter.
Care requirements after
installed
Moisture
stress and competing vegetation decrease seedling growth and survival.
Normal rate of growth or
spread; lifespan
Medium growth rate, 75 feet after 40-50 years. Long lived, often exceeding 500 years.
Sources cited
Burns, R. and Honkala. 1990. Silvics of
Dirr,
M.1998. Manual of Woody
Landscape Plants.
Pojar and MacKinnon. 1994. Plants
of the
Young,
C. and Young, J. 1986. Collecting,
Processing and Germinating Seeds of Wildland Plants.
Young,
C. and Young, J. 1992. Seeds
of Woody Plants in
Data compiled by Katie McGowan