Encina, California live oak, Coast Live Oak
Quercus agrifolia
Family: Fagaceae
What it is like
Bloom Color: Brown. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Rounded, Spreading or horizontal.
Quercus agrifolia is an evergreen Tree growing to 15 m (49ft) by 8 m (26ft) at a slow rate. See above for USDA hardiness. It is hardy to UK zone 8. It is in leaf all year, in flower from April to May, and the seeds ripen in October. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and is pollinated by Wind. Suitable for: medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil. The plant can tolerates strong winds but not maritime exposure.
Height (m): 15
Where it is found
Forming open groves of great extent in valleys and on not too dry slopes in woods below 1000 metres, it is also found on coastal sand dunes.
South-western N. America - California.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 3
Seed - cooked. Used as a staple food by several native North American Indian tribes. 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, which is up to 4cm long and 2cm wide, 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.
Seed: includes nuts, cereals, peas and beans.
Medicine
Rating: 2
Any galls produced on the tree are strongly astringent and can be used in the treatment of haemorrhages, chronic diarrhoea, dysentery etc. A decoction of the chipped bark has been used as a wash on skin sores.
Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.
Dysentery: Used in treating dysentery - an infection of the intestines that causes diarrhoea containing blood or mucus.
Skin: Plants used in miscellaneous treatments for the skin.
Other
Rating: 2
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. The seed cups are used as buttons. Wood - coarse grained, hard, very heavy, very brittle. It is not exploited commercially as a wood, though it is valued as a fuel.
Buttons: Plants that can be used as buttons. Not including making buttons from wood.
Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.
Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.
Tannin: An astringent substance obtaied from plants, it is used medicinally, as a dye and mordant, stabilizer in pesticide etc.
Wood: A list of the trees and shrubs that are noted for having useful wood.
How it is grown
Landscape Uses:Pest tolerant, Aggressive surface roots possible, Pollard, Specimen, Street tree. Prefers a good deep fertile loam which can be on the stiff side. Plants are lime tolerant. Young plants tolerate reasonable levels of side shade. Tolerates moderate exposure, surviving well but being somewhat stunted. Trees are hardy in Britain if they are not too exposed, though another report says that they are wind-resistant. Trees grow well in S.W. England. Intolerant of root disturbance, trees should be planted in their permanent positions whilst young. A slow-growing but long-lived tree in the wild. Plants only fruit occasionally in Britain, though they fruited very heavily at Kew in the hot summer of 1989. The tree flowers on new growth produced in spring, the seed ripening in its first year. Hybridizes freely with other members of the genus. This species is notably resistant to honey fungus. Special Features: North American native, Inconspicuous flowers or blooms.
Propagating it: 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. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.
Best place to grow: Woodland Garden Canopy;
Habit: Tree
Hardiness: 8-11
Growth: Slow
Soil: Medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist