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| ## blue oak {#blue-oak .Title-Header}                                 |
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| *Quercus douglasii* Hook. & Arn.                                      |
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| Plant Symbol = QUDO                                                   |
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Contributed by: USDA NRCS National Plant Data Center

### ![](media/image2.jpeg){width="2.5in" height="2.125in"}

# Uses

*Ethnobotanic*: Blue oaks had and continue to have significant meaning
to native cultures. The most significant use of blue oak was for its
highly desirable acorns for food. Acorns were shelled, dried, pounded
into flour, sifted for fineness, leached of bitter tannins, and mixed
with other acorn types such as black oak (*Quercus kelloggii*) and
prepared as mush, soup, paddies, or bread. Called \"acorn\" by
contemporary gatherers, this food is still relished for ceremonies,
festivals, dances, and family gatherings.

California\'s blue oak provided many resources to California Indian
people including medicine, dyes, utensils, games, toys, and construction
materials. The inner bark of the blue oak was boiled and the brew drank
for relief of arthritis by the Kawaiisu. Acorns served as bait in traps
and snares to catch pigeons, flickers, quail, and jays by the
Gabrielino, Sierra Miwok and other tribes. California blue oaks grow new
sprouts vigorously after a fire and these young shoots exhibit highly
desirable qualities for manufacturing products. These characteristics
include flexibility, length, no lateral branching, easily split, and
straightness. These shoots were used for basketry and oak sprouts were
reputed to have great strength. Types of baskets included Miwok, Pomo,
and Maidu cradleboards with frameworks of oak shoots, and Kawaiisu
twined work-baskets made with rims of blue oak branches. The Salinan
along the central coast made seed-beaters with a looped stick of oak.
The Yana used an oak paddle in cooking and the Achomawi made spoons of
oak. The Kawaiisu made a ladle about a foot long that was carved from
the wood of blue oak. Forked oak sticks, darkened by charring, were used
as fake antlers on deer masks of the Sierra Miwok for hunting purposes.
The Maidu of Chico Rancheria constructed their houses with posts of oak.
The Western Mono also used young oak switches as construction materials
for certain structures such as acorn granary frameworks. Digging sticks
were made of blue oak by the Western Mono for roasting yucca bulbs, blue
oak was preferred as firewood by the Kawaiisu and the pith of the oak
was used for starting fires. Fallen oak limbs make excellent firewood,
because the coals retain heat and the Shasta, Sierra Miwok, and many
other tribes used the wood. Acorns were utilized by many tribes in the
manufacture of toys including acorn buzzers and acorn tops. Split acorns
often formed dice, which could be rolled upon a flat, coiled basketry
tray. The Miwok, the Western Mono, Pomo, Sinkyone, and other cultural
groups used these.

*Wildlife*: It is well known that bears (*Ursus americanus*), ground
squirrels (*Spermophilus scrofa*), jays (*Cyanocitta steller*i),
band-tailed pigeons (*Columba fasciata*), acorn woodpeckers (*Melanerpes
formicivorus*), pocket gophers (*Thomomys bottae*), deer mice
(*Peromyscus* spp.) and black-tailed deer (*Odocileus hemionus*), among
many other animals find acorns a favorite food source.

# Status

Please consult the PLANTS Web site and your State Department of Natural
Resources for this plant's current status, such as, state noxious status
and wetland indicator values.

# Description

*General*: Oak Family (Fagaceae). Blue oak is a deciduous tree that is
endemic to California. It has a rounded crown and grows from 6-20 m.
high. The gray bark is shallowly checked into small thin scales. The
leaves are shallowly lobed and blue-green above. The acorns mature in
one year, are oval, and have slightly tubercled scales.

# Distribution

For current distribution, please consult the Plant Profile page for this
species on the PLANTS Web site.

![](media/image3.jpeg){width="2.098611111111111in"
height="1.7798611111111111in"}

# Establishment

*Adaptation*: Blue oak woodlands cover 3 million acres in California,
one-half of all oak covered lands. It is the most abundant hardwood
forest type in the state. Blue oak may occur in near pure stands in
dense woodland or savanna. It may also occur as a dominant in mixed
stands that include foothill pine (*Pinus sabiniana*), interior live oak
(*Quercus wislizenii*), valley oak (*Quercus lobata*), and/or coast live
oak (*Quercus agrifolia*), or as a minor component in mixed stands of
oaks and other hardwoods.

If possible, gather acorns from many different trees locally, to
maintain genetic diversity of blue oak and to ensure that the plants are
adapted to the site. The seeds of most oaks are short-lived and must be
sown or refrigerated quickly, otherwise they lose their ability to
germinate. They are best gathered directly from the tree or from the
ground within a short time of their dropping, usually within several
days. To test their ripeness, select an acorn that is still in its cap
and twist it lightly. If it pops out of the cap, the acorn is ripe.
Store the seeds without their caps in a grocery sack until ready to
plant. The seeds can be sown in autumn outdoors (see under direct
seeding), or if the seeds are started in pots in the greenhouse in the
early spring, they should be stratified for one and one-half months
between 33 and 40 degrees in a refrigerator in a mix.

Fill a gallon Ziploc™ bag about half full with acorns, and then add
about a cup of dry perlite and a little bit of vermiculite (3:1
mixture). Shake the bag to distribute the perlite around the acorns,
label the bag, and place it in the refrigerator. Check the bag weekly
and discard moldy acorns. Any acorns that have germinated need to be
taken out of the bag and sown. Plant the seeds on their sides directly
in long, deep pots (2 in. in diameter by 10 inches long) with potting
soil and a slow release fertilizer. Water the tubes and place them in
diffused light in the nursery or outside, making sure to keep each tube
suspended off the ground or bench so the large air holes at the bottom
of the tube are exposed. When the tree roots hit the air, they\'ll stop
growing. Water the pots when the surface of the soil is dry to the
touch. Do not over-water.

Plant the seedlings the following winter in a sunny location and water
the transplants to ensure sufficient moisture and eliminate air pockets.
Be careful to keep the soil from falling off of the roots. Place the
seedlings in the ground such that the top of the soil from the container
is even with the ground line. Use a pick mattock for planting, which has
a pick on one surface and a triangular wedge on the other surface. Break
up the soil, which will foster root growth. Protect the seedlings from
weeds, drying winds, grasshoppers, and small and large mammals that
might feed on the roots, leaves, or trunks. Also, water the seedlings
deeply the first summer. A good seedling protector is essential and can
be a simple wire window screen mesh and wooden stake. Bend the mesh into
a cylinder that is about 6-8 inches in diameter and 3 feet tall. Attach
the mesh cylinder onto the wooden stake with staples or carpet tacks.
Place the tube over the seedling and pound the stake into the ground.
Seedlings should be kept free of vegetation for 2 to 3 feet surrounding
each seedling.

*Direct Seeding*: Pick acorns without insect exit holes or diseases.
Store acorns for one and one half months in a sealed plastic bag in the
refrigerator. Dig a hole with the trowel, shovel, or hoe and be sure to
break up the soil much deeper (one to two feet) than the acorn is
planted and backfill with loosened soil to accommodate the growing of
roots. Plant the acorns on their sides, one to two inches deep in the
fall of the year. Plant several acorns in each hole and thin multiple
seedlings down to a single most vigorous plant. Water the acorns deeply
the first summer. Weed several feet around each seedling for several
years. Protect the seedlings from animals until well established.

# Management

Keep lawns and plants that require a lot of moisture away from the oaks.
Blue oak should not be irrigated accept in years of unusually low
rainfall. If a drought year, supplemental watering can take place in the
spring to complement natural rainfall. Water the soil from halfway
between the trunk and the drip line to 10-15 feet beyond, allowing water
to penetrate the soil to a depth of 18 to 24 inches. It may be necessary
to water for 4 to 6 hours to get water to this depth. Keep water at
least 10 feet away from the trunk. Native plants that are
drought-tolerant and shade-tolerant and require no summer water can be
planted under the oaks, such as California brome (*Bromus carinatus*),
deergrass (*Muhlenbergia rigens*), sego lily (*Calochortus* spp.), and
bluedicks (*Dichelostemma* spp.), among others. Light pruning can be
done in the winter on mature oaks to remove weak, diseased, and dead
branches, but never top oaks.

Once established, blue oak is quite fire-tolerant. Many tribes in
California set frequent light-surface fires in areas of blue oak to
ensure continual yields of high-quality acorn. Major reasons for their
burning included the following: 1) facilitating acorn collection; (2)
increasing the quality and quantity of acorn production through
decreasing diseases; (3) increasing the quality and quantity of acorn
production through decreasing acorn pests; 4) stimulating the production
of straight shoots (epicormic) for the making of cultural items; 5)
decreasing the likelihood of major conflagrations that would destroy the
oaks; 6) burning for mushrooms; and 7) increasing edible grasses and
other seed-bearing herbaceous plants under the oaks and within the
surrounding woodlands.

# Cultivars, Improved and Selected Materials (and area of origin)

Readily available from most native plant nurseries within its range.
Contact your local Natural Resources Conservation Service (formerly Soil
Conservation Service) office for more information. Look in the phone
book under "United States Government." The Natural Resources
Conservation Service will be listed under the subheading "Department of
Agriculture."

# References

Barrett, S.A. & E.W. Gifford 1933. *Miwok material culture*. Bulletin of
the Public Museum of the City of Milwaukee 2(4):117-376.

CalPhotos 2000. *Quercus douglasii*. Version: 000229. CalFlora, Inc.,
Berkeley, California.

\<http://elib.cs.berkeley.edu/cgi/img_query?seq_num=11938&one=T\>.

Dagit, R. 1998. *Transplanting oak trees*. Growing Native 9(6):1-24.
Editor, L. Lacy. The Newsletter of the Growing Native Research
Institute.

Hagen, B.W. 1990. *Keeping native California oaks healthy*. Tree Notes
#7. California Department of Forestry and Fire Protection.

Hagen, B.W., B.D. Coate, & K. Oldham 1991. *Compatible plants under and
around oaks*.

Hill, D. 1978. *The Indians of Chico Rancheria*. State of California,
the Resources Agency. Department of Parks and Recreation, Sacramento,
California. 108 pp.

Keator, G. 1998. *The life of an oak: an intimate portrait*. Heyday
Books and California Oak Foundation. Berkeley, California.

Martin, A.C., H.S. Zim, &A.L. Nelson 1951. *American wildlife and
plants: A guide to wildlife food habits.* Dover Publications, New York,
New York.

Mason, J.A. 1912. *The ethnology of the Salinan Indians*. University of
California Publications in American Archaeology and Ethnology. Vol.
10(4). pp. 97-240.

McDonald, P.M. 1990. *Silvics of North America*. Volume 2, Hardwoods.
Burns, R.M. and B.H. Honkala, tech. coords. Agriculture Handbook 654.
U.S. Department of Agriculture, Washington, DC.

Schulz, P.E. 1988. *Indians of Lassen Volcanic National Park and
vicinity*. Loomis Museum Association. Lassen Volcanic National Park,
Mineral, California. 160 pp.

USDA, NRCS 2000. *The PLANTS database*. \<http://plants.usda.gov\>.
Version: 000229. National Plant Data Center, Baton Rouge, Louisiana.

Zigmond, M.L. 1981. *Kawaiisu ethnobotany*. University of Utah Press,
Salt Lake City, Utah.

# Prepared By and Species Coordinator

*M. Kat Anderson*

USDA, NRCS, National Plant Data Center

Department of Plant Sciences, University of California, Davis,
California

Edited 05dec00 jsp; 29may03 ahv; 060809 jsp

For more information about this and other plants, please contact your
local NRCS field office or Conservation District, and visit the PLANTS
Web site\<[http://plants.usda.gov](http://plants.usda.gov/)\> or the
Plant Materials Program Web site
\<[http://Plant-Materials.nrcs.usda.gov](http://Plant-Materials.nrcs.usda.gov/)\>

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