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Quercus douglasii - Hook.&Arn.
                 
Common Name Blue Oak
Family Fagaceae
USDA hardiness 8-11
Known Hazards None known
Habitats Dry soils in valleys, rolling hills and lower mountain slopes to 1350 metres[62, 82], often forming extensive stands[229].
Range South-western N. America - California.
Edibility Rating  
Other Uses  
Weed Potential No
Medicinal Rating  
Care
Fully Hardy Well drained soil Moist Soil Semi-shade Full sun

Summary
Bloom Color: Brown. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Rounded, Spreading or horizontal.

Quercus douglasii Blue Oak


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Quercus douglasii Blue Oak
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Physical Characteristics
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Quercus douglasii is a deciduous Tree growing to 12 m (39ft 4in) at a slow rate.
It is hardy to zone (UK) 7 and is not frost tender. It is in flower in May, and the seeds ripen in October. The flowers are monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and are pollinated by Wind.Suitable for: medium (loamy) and heavy (clay) soils. Suitable pH: acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry or moist soil. The plant can tolerates strong winds but not maritime exposure.

Synonyms

Habitats
Woodland Garden Canopy;
Edible Uses
Edible Parts: Seed.
Edible Uses: Coffee.

Seed - cooked[257]. The seed has been used as a staple food by some native North American Indian tribes[257]. Somewhat sweet[62, 4, 105, 161]. A good size, to 25mm long and wide[82, 200]. It can be dried, ground into a powder and used as a thickening in stews etc or mixed with cereals for making bread. The seed from some trees contains bitter tannins, these can be leached out by thoroughly washing the seed in running water though many minerals will also be lost. Either the whole seed can be used or the seed can be dried and ground it into a powder. It can take several days or even weeks to properly leach whole seeds, one method was to wrap them in a cloth bag and place them in a stream. Leaching the powder is quicker. A simple taste test can tell when the tannin has been leached. The traditional method of preparing the seed was to bury it in boggy ground overwinter. The germinating seed was dug up in the spring when it would have lost most of its astringency. The roasted seed is a coffee substitute.
Medicinal Uses


Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.

Astringent;  Poultice;  Skin.

Any galls produced on the tree are strongly astringent and can be used in the treatment of haemorrhages, chronic diarrhoea, dysentery etc[4]. A poultice of the ground galls and salt has been used in the treatment of burns, sores and cuts[257]. It has also been used as a wash for sore eyes[257]. The leaves have been chewed as a treatment for sore throats[257].
Other Uses
Adhesive;  Basketry;  Buttons;  Fuel;  Repellent;  Tannin;  Wood.

A mulch of the leaves repels slugs, grubs etc, though fresh leaves should not be used as these can inhibit plant growth[20]. Oak galls are excrescences that are sometimes produced in great numbers on the tree and are caused by the activity of the larvae of different insects. The insects live inside these galls, obtaining their nutrient therein. When the insect pupates and leaves, the gall can be used as a rich source of tannin, that can also be used as a dyestuff[4]. The branches have been used to make rims for twined work baskets[257]. The acorn meal has been used to mend cracks in clay pots[257]. The seed cups are used as buttons[5]. Wood - hard, heavy, strong, brittle. It has a strong cross-grain and is difficult to split[229]. Of little commercial value, it is used mainly for fuel[82, 229].
Cultivation details
Landscape Uses:Border, Erosion control, Massing, Screen, Specimen, Street tree. Prefers a good deep fertile loam which can be on the stiff side[1, 11]. Young plants tolerate reasonable levels of side shade[200]. Tolerates moderate exposure, surviving well but being somewhat stunted[200]. Prefers warmer summers than are usually experienced in Britain, trees often grow poorly in this country and fail to properly ripen their wood resulting in frost damage overwinter[200]. A slow-growing but long-lived tree. Seed production is cyclic, a year of high yields being followed by 2 - 4 years of low production[229]. The tree flowers on new growth produced in spring, the seed ripening in its first year[200, 229]. This species is notably resistant to honey fungus[88, 200]. Hybridizes freely with other members of the genus[200]. Intolerant of root disturbance, trees should be planted in their permanent positions whilst young[11]. Special Features: North American native, Inconspicuous flowers or blooms.
Propagation
Seed - it quickly loses viability if it is allowed to dry out. It can be stored moist and cool overwinter but is best sown as soon as it is ripe in an outdoor seed bed, though it must be protected from mice, squirrels etc. Small quantities of seed can be sown in deep pots in a cold frame. Plants produce a deep taproot and need to be planted out into their permanent positions as soon as possible, in fact seed sown in situ will produce the best trees[11]. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.
Other Names
Found In
Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

Conservation Status
IUCN Red List of Threatened Plants Status :
Related Plants
Latin NameCommon NameEdibility RatingMedicinal Rating
Quercus acutaJapanese Evergreen Oak22
Quercus acutissimaSawthorn Oak22
Quercus agrifoliaEncina, California live oak, Coast Live Oak32
Quercus albaWhite Oak, Hybrid oak32
Quercus alienaOriental White Oak22
Quercus aucheriBoz-Pirnal Oak42
Quercus bicolorSwamp White Oak42
Quercus cerrisTurkey Oak, European turkey oak32
Quercus chrysolepisLive Oak, Canyon live oak22
Quercus cocciferaKermes Oak32
Quercus coccineaScarlet Oak22
Quercus dentataJapanese Emperor Oak, Daimyo oak22
Quercus durataCalifornia Scrub Oak, Leather oak22
Quercus ellipsoidalisNorthern Pin Oak22
Quercus emoryiBlack Oak, Emory oak32
Quercus engelmanniiEvergreen Oak, Engelmann oak, Mesa Oak22
Quercus falcataSouthern Red Oak, Cherrybark Oak, Spanish Oak, Southern Red Oak12
Quercus floribunda 22
Quercus frainettoHungarian Oak, Italian Oak, Forest Green Oak42
Quercus fruticosa 32
Quercus gambeliiShin Oak, Gambel oak, Rocky Mountain White Oak32
Quercus garryanaOregon White Oak, Garry Oak22
Quercus glaucaRing-cup oak , Ring Cupped Oak, Blue Japanese Oak32
Quercus hispanica 32
Quercus ilexHolly Oak, Evergreen Oak52
Quercus ilex ballotaHolm Oak52
Quercus imbricariaShingle Oak, Northern Laurel Oak22
Quercus infectoriaAleppo Oak, Oak22
Quercus ithaburensis macrolepisValonia Oak42
123
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Subject : Quercus douglasii  

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