Common Name: White Oak

General Information

Quercus alba is a deciduous tree with a wide, irregular crown. it usually grows up to 25 metres tall, though it can sometimes reach 45 metres. The bole can be 90 - 180cm in diameter[, ]
This is one of the most important timbers in N. America, widely harvested from the wild and used in cabinet making, construction, agricultural tools etc. The seeds are also often harvested for mainly local use as a food, whilst the plant also has a range of medicinal uses. The tree is sometimes cultivated for its wood and its seeds, and is often grown as an ornamental in larger gardens, parks etc[].
Quercus alba is very widespread in its distribution; it is known to be found on many soil types; and it is assumed that the species population size is large. Though a decline in parts of its range has been documented, it is not believed to approach the threshold for any threatened category. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known 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[].

Botanical References

, ,

Range

Eastern N. America - Ontario and Quebec, south to Texas and Florida

Habitat

Dry woods[], gravelly ridges, sandy plains, rich uplands and moist bottoms[]. Moist to fairly dry, deciduous forests usually on deeper, well-drained loams, also on thin soils on dry upland slopes, sometimes on barrens; at elevations up to 1,600 m[]

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	20.00 m
Growth Rate	Slow
Pollinators	Wind
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Quercus alba is a very cold-hardy tree, tolerating temperatures down to around -30°c when dormant. It grows best in areas with hot summers. In areas with cooler summers, such as the maritime regions of the temperate zone, it often grows poorly, failing to properly ripen its wood and suffering frost damage over the winter[, ]. There are, however, a number of trees 15 metres or more tall in Britain, mainly in the south-east of the country[].
Found in the wild on a range of soil types, it prefers a good deep fertile, well-drained loam which can be on the stiff side[, , ]. The best specimens are found in deep rich well-drained loamy soils[]. Somewhat lime tolerant[], though it prefers slightly acid conditions[]. Young plants tolerate reasonable levels of side shade[]. Tolerates moderate exposure, surviving well but being somewhat stunted[]. Established plants are fairly drought tolerant[].
Quercus alba used to be considered the source of the finest and most durable oak lumber in America, being used for furniture and shipbuilding. Now it has been replaced almost entirely in commerce by various species of eastern red oak (including Quercus rubra, Quercus velutina, and Quercus falcata ) that are more common, have faster growth rates and greater yields. These red oaks also lack tyloses and therefore are more suited to pressure treating with preservatives, even though they are less decay-resistant without treatment[].
Sometimes cultivated for its edible seed, there are some named varieties[].
A slow-groing but long-lived tree[].
Trees take about 30 years before they start to bear good crops of seed, they then have heavy crops about every 3 years with light crops in the other years[]. They continue to yield commercial crops for about 120 years[].
The tree flowers on new growth produced in spring, the seed ripening in its first year[, ].
The tree is sometimes grown as an ornamental[].
Seedlings quickly develop a taproot and become intolerant of root disturbance. They should be planted in their permanent positions whilst young, though they may require protection for the first winter or two[, ].
Hybridizes freely with other members of the genus[]. Many hybrid forms with other white oak species have been reported, with several of them being given botanical names[].
Plants in this genus are notably resistant to honey fungus[].

Edible Uses

Seed - raw or cooked[]. Somewhat sweet[]. The seed is about 12 - 25mm long and 9 - 18mm wide[, ] and ripens in its first year[]. It contains about 6% protein and 65% carbohydrates[]. It is low in tannin and needs little if any leaching. It is said that those seeds with red or pink blotches on the shell are the sweetest[]. The seed can be roasted and then eaten, its taste is something like a cross between sunflower seeds and popcorn[].
The seed is usually cooked before eating, though it can also be eaten raw. It can be eaten whole, though it is more commonly dried, then ground into a powder and used as a thickening in stews etc or mixed with cereals for making bread.
In some species, especially many of those classified as 'white oaks', the seeds are low in tannins and have a more or less sweet and agreeable flavour. The seed of most species, however, have a very bitter flavour, due especially to the presence of tannins. In these species there are various processes that can remove or at least reduce the amount of these bitter substances (although other water-soluble substances, including some minerals, will also be removed).
Tannins are water-soluble and therefore the easiest way to remove or reduce tannin levels is by soaking in water. A few different methods are listed:-
A traditional method of preparing the seed was to bury it in boggy ground overwinter and allow the wet soil to gradually leach the tannins. The germinating seed was dug up in the spring when it would have lost most of its astringency and bitterness.
Another method was to wrap the seeds in a cloth bag and place them in a stream for several weeks.
Drying the seed and grinding it to a powder before soaking speeds up the process. The fastest method is to use hot water, by cooking the powder and changing the water several times until the cooking water is no longer bitter. Alternatively, you can use cold water (which is reported to produce the best quality flour). In this case, you soak the powdered seed in cold water for 12 - 24 hours then discard the water. Repeat this process for a number of times until the soak water is no longer bitter.

The roasted seed is a coffee substitute that is free from caffeine[].

Medicinal

White oak was often used medicinally by several native North American Indian tribes, who valued it especially for its antiseptic and astringent properties and used it in the treatment of many complaints[]. It is little, if at all, used in modern herbalism.

The inner bark contains 6 - 11% tannin, it has powerful antiseptic and astringent properties and is also expectorant and tonic[, , , ]. The bark is boiled and the liquid drunk in the treatment of bleeding piles and diarrhoea, intermittent fevers, coughs and colds, consumption, asthma, lost voice etc[, ]. The bark has been chewed as a treatment for mouth sores[]. Externally, it is used as a wash for skin eruptions, burns, rashes, bruises, ulcers etc and as a vaginal douche[, ]. It has also been used as a wash for muscular pains[]. The bark is best collected in the spring[].

Oils obtained from pressed acorns have been used to alleviate pain in the joints[].

Any galls produced on the tree are rich in tannins and therefore strongly astringent. They can be used in the treatment of various conditions including haemorrhages, chronic diarrhoea, dysentery, as a wash on cuts and wounds, as a mouthwash to treat toothache or gum problems etc[].

Agroforestry Uses:

White oak is potentially valuable for use in reforestation projects, and appears to have potential for use on other types of disturbed sites.
It has been planted on strip-mined lands in Ohio, Indiana, and Illinois, and has exhibited good growth and survival on cast overburden and graded topsoil overlying mine spoils. It is well adapted to loamy and clayey spoils with a pH of 5.5 to 8.0[]

Other Uses

The leaves of most species in this genus are more or less rich in tannins. A mulch of the leaves can be placed around vulnerable plants in order to repel slugs, snails, grubs etc. Fresh leaves should be used with caution, since these can utilize some of the nitrogen in the soil and this inhibit plant growth[, ].

The bark is a rich source of tannin[, ].

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[]. A brown dye is obtained from the bark or from the galls, it does not require a mordant[]. Yellow, chrome and gold can also be obtained if mordants are used[].

The wood is strong, very heavy, hard, tough, strong, close grained, durable[, , , , ]. It weighs about 46lb per cubic foot[].When properly dried treated, the wood glues well, machines very well and accepts a variety of finishes One of the most important timbers in N. America, it is used for cabinet making, furniture, panelling, flooring, construction, mine props, agricultural tools etc[, , , , ]. It is highly valued for making the staves of barrels for storing wine and liquor[, ].
The wood is a good fuel[, giving off a lot of heat46, ].

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[]. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.