Garry Oak – Fagales Fagaceae Quercus garryana


Identification & Description:
A decidious tree growing to 18m by 10m at a slow rate. It is hardy to zone 6 and is 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. We rate it 2 out of 5 for usefulness.

Garry oaks, Quercus Garryana, also known as Oregon White Oak, is a species of oak unique to the Pacific Northwest region of North America including Vancouver Island and the southern Gulf Islands. These hardwood trees date from before the ice ages, and are found on steep south- and west-facing sites with rapidly drained soil, in areas with a Mediterranean-type climate (sites that, coincidentally, also favour vineyards!).

The “Garry” refers to Nicholas Garry, deputy governor of the Hudson’s Bay Company when the company was active in the Pacific Northwest during the early nineteenth century.

The plant prefers medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. The plant prefers acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It requires moist soil and can tolerate drought. The plant can tolerates strong winds but not maritime exposure.

Common Names:
Oregon White Oak, Garry’s Oak, Post Oak, White Oak

Unique Features:
• Only native oak in British Columbia
• Slow growing
• Leaves turn brown in the fall so are not particularly colourful like other oaks
• Many birds, small mammals and insects use the oak as their home

Garry oak forms open parkland and meadows that are scattered with Douglas-fir and a lush spring display of herbs – camas, Easter lilies, western buttercups, and shootingstars. These meadows are threatened by urban development.

A diverse bird community makes its home in Garry oak meadows, as well as numerous mammals and insects. Garter snakes and alligator lizards can be seen basking on sun-warmed rocks.

Edible Uses
Coffee; Seed.
Seed – raw or cooked. Up to 25mm long. Up to 32mm long and 25mm wide according to other reports, which also said that it has a sweet taste. The seed is ground into a powder and used in making bread etc, it is a good thickener for soups and stews. The seed has a high content of bitter tannins, these can be leached out by thoroughly washing the dried and ground up seed in 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.

Other Uses
Garry oak wood was used by coastal peoples for combs and digging sticks as well as for fuel. They also ate the acorns either roasted or steamed. They managed the Garry oak ecosystem by underburning in order to cultivate a supply of camas bulbs. Camas was an important food source for many Coastal groups.

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.

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.

Wood – hard, heavy, strong, tough, close grained, durable, easy to split. Used for furniture, cabinet making, general construction etc and also for fence posts and fuel.

Cultivation details
Prefers a good deep fertile loam which can be on the stiff side. Lime tolerant. Young plants tolerate reasonable levels of side shade. Tolerates moderate exposure, surviving well but being somewhat stunted.

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.

A slow-growing and drought tolerant tree, it can live for 500 years. Seed production is cyclic, with a year of high production being followed by 2 – 3 years of lower yields. The tree flowers on new growth produced in spring, the seed ripening in its first year.

Intolerant of root disturbance, trees should be planted in their permanent positions whilst young.

Hybridizes freely with other members of the genus.

Plants in this genus are notably resistant to honey fungus.