
Quercus garryana
Quercus garryana
Safety & Hazards
All parts of the plant contain tannins. Whilst tannins are found in many foods, and have a range of medicinal uses. They are usually only present in low concentrations. In some foods made from oaks (particularly the seeds), the tannin content can be quite high unless the food is treated to reduce tannin content. Tannins are only of low toxicity and, because of their bitter taste and astringency, are unlikely to be eaten in large quantities. However, if they are taken in excess, they can cause stomach pains; constipation followed by bloody diarrhoea: excessive thirst; and excessive urination[1].
Cultivation Details
Quercus garryana is a fairly cold-hardy tree, tolerating temperatures down to around -20°c when dormant. It grows in the mild maritime climates of Oregon as well as the more mediterranean climate of California. Summer temperatures usually avereage a bit more than 20°c and mean annual precipitation can range from 250 - 2,500mm[2]. Plants generally require a sunny position[2], though young plants tolerate reasonable levels of side shade[3]. Prefers a good deep fertile loam which can be on the stiff side[4, 5]. Plants in the wild are found on a variety of soils ranging from dry to very moist and poorly to rapidly draining; gravelly and heavy clay substrates are tolerated[2]. Lime tolerant[6]. Tolerates moderate exposure, surviving well but being somewhat stunted[3]. Often crowded out by species that grow faster and taller, this species has no strict soil preference and can be found on rocky sites as well as heavy clays, and can withstand both lengthy flooding and drought[7]. The tree is sometimes grown as an ornamental and shade tree[2]. A slow-growing and drought tolerant tree[6, 8], it can live for 500 years[8]. Seed production is cyclic, with a year of high production being followed by 2 - 3 years of lower yields[8]. The tree flowers on new growth produced in spring, the seed ripening in its first year[3, 8]. Trees can resprout from the base if cut back or top-killed by fire[2]. Seedlings soon develop a taproot and become intolerant of root disturbance, they should be planted into their permanent positions whilst young[5]. Hybridizes freely with other members of the genus[3]. Plants in this genus are notably resistant to honey fungus[3].
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[5]. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Quercus+garryana>
Pollinators
Wind
References
- [1]Poisonous Plants of North Carolina — http://www.ces.ncsu.edu/depts/hort/consumer/poison/poison.htm ↩︎An excellent concise but comprehensive guide to toxic plants that grow in N. Carolina. It lists even those plants that are of very low toxicity, including several well-known food plants such as carrots and potatoes.
- [2]Fire Effects Information System — http://www.feis-crs.org/feis/ ↩︎An on-line information site with comprehensive information on over 1,100 species of plant. Mainly developed to supply information on the effects of fire on plants and animals, it also contains a wealth of other information on the plants
- [3]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
- [4]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
- [5]Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. — Bean. W. · Murray · 1981 · ISBN - ↩︎A classic with a wealth of information on the plants, but poor on pictures.
- [6]The RHS Gardener's Encyclopedia of Plants and Flowers — Brickell. C. · Dorling Kindersley Publishers Ltd. · 1990 · ISBN 0-86318-386-7 ↩︎Excellent range of photographs, some cultivation details but very little information on plant uses.
- [7]IUCN Red List of Threatened Species — http://www.iucnredlist.org/ ↩︎A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
- [8]The Complete Trees of N. America. Field Guide and Natural History. — Elias. T. · Van Nostrand Reinhold Co. · 1980 · ISBN 0442238622 ↩︎A very good concise guide. Gives habitats, good descriptions, maps showing distribution and a few of the uses. It also includes the many shrubs that occasionally reach tree proportions.
- [9]Flora of N. America — http://flora.huh.harvard.edu/fna/ ↩︎An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
- [10]Identification Guide to the Trees of Canada — Lauriault. J. · Fitzhenry and Whiteside, Ontario. · 1989 · ISBN 0889025649 ↩︎Very good on identification for non-experts, the book also has a lot of information on plant uses.
- [11]Cornucopia - A Source Book of Edible Plants. — Facciola. S. · Kampong Publications · 1990 · ISBN 0-9628087-0-9 ↩︎Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
- [12]A Modern Herbal. — Grieve. · Penguin · 1984 · ISBN 0-14-046-440-9 ↩︎Not so modern (1930's?) but lots of information, mainly temperate plants.
- [13]Antibacterial and Antifungal Activities of Some Quercus Species Growing in Turkey — Didem Söhretoğlu; Melike Ekizoğlu; Ekrem Kiliç; M. Koray Sak · 2007 ↩︎
- [14]Native American Ethnobotany — Moerman. D. · Timber Press. Oregon. · 1998 · ISBN 0-88192-453-9 ↩︎Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
- [15]Companion Planting for Successful Gardening. — Riotte. L. · Garden Way, Vermont, USA. · 1978 · ISBN 0-88266-064-0 ↩︎Fairly good.
- [16]Flora of Guatemala — Standley P.C. & J. A. Steyermark · 1946 - 1976 · http://www.archive.org/ ↩︎A superb reference, though somewhat dated. Gives lots of plant uses as well as information on plant habit and habitat. The entire flora (13 volumes) can now be downloaded from http://www.archive.org/
- [17]Dictionary of Economic Plants. — Uphof. J. C. Th. · Weinheim · 1959 · ISBN - ↩︎An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
- [18]A Dictionary of Plants Used by Man. — Usher. G. · Constable · 1974 · ISBN 0094579202 ↩︎Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
- [19]Manual of the Trees of N. America. — Sargent. C. S. · Dover Publications Inc. New York. · 1965 · http://www.biodiversitylibrary.org/ · ISBN 0-486-20278-X ↩︎Two volumes, a comprehensive listing of N. American trees though a bit out of date now. Good details on habitats, some details on plant uses. Not really for the casual reader. It can be downloaded from the internet.
- [20]Economic Botany. — Hill. A. F. · The Maple Press · 1952 · ISBN - ↩︎Not very comprehensive, but it is quite readable and goes into some detail about the plants it does cover.
- [PFAF]Plants for a Future — pfaf.org ↩︎