Quercus virginiana
Live oak is a massive, picturesque, and wide-spreading evergreen tree with large, horizontal, and arching branches that give this oak its unique shape and distinction. In an open landscape, they may reach approximately 40 to 80 feet tall and 60 to 100 feet wide. However, in the forest, it stands more erect, growing to 100 feet tall. This Willoughby name simply means that these oaks seeds (acorns) were harvested and propagated from the trees surrounding Willoughby Spit. Due to this fact, the trees here are more salt tolerant and flood tolerant than other live oaks, because they have been generically capable of surviving in the Willoughby area.
This tree grows moderately fast in youth, and if properly located and maintained, may produce 2 to 2½ feet of growth per year. Trees grown outside the coastal region will grow more slowly. The growth rate also slows with age. As one of the longest-lived oaks, some live oaks may live 200 to 300 years.
The live oak is probably best known for its massive horizontal limbs that give older trees their majestic appearance. The trunk can grow to more than six feet in diameter. Live oak leaves remain on the tree through the winter, then yellow and drop as new leaves expand in the spring. However, trees growing further inland become semi-evergreen and lose some of their leaves during fall and winter. The waxy leaves are resistant to salt spray.
The small (1 inch) acorns, produced in clusters of one to five, are dark brown to black when ripe, and are a primary food for many wildlife species along the coast.
Live oak is susceptible to leaf blister, a fungal gall that disfigures leaves and may cause some leaf drop, but does no appreciable harm. Rake up and dispose of or burn dropped foliage to reduce the severity of this disease the following year. Several insect galls may become a minor problem, but control measures are generally not required for leaf insect galls. Oak wilt is a serious fungal disease that can kill infected oak trees within a year or two.
Live oaks are reminiscent of the Old South, especially when planted along avenues or drives leading to old plantations. Although used extensively for street tree plantings, in time, the roots will lift sidewalks or streets if planted too close. Live oak does well as a lawn specimen when provided plenty of space to grow.
Although grown best in well-drained, sandy soils with plenty of moisture, it tolerates drier, more compacted soils. Once established, live oak is drought-resistant. It prefers full sun but tolerates more shade than other oaks because its leaves function throughout winter.
Pruning is only necessary to develop a strong branch structure early in the life of the tree. Train trees to grow a central leader by eliminating young multiple trunks and branches. Prune in mid-to-late summer to avoid oak wilt disease.
Propagation of 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.
Ethnobotanical Information (Ethnobotany is the scientific study of the traditional knowledge and customs of a people concerning plants and their medical, religious, and other uses.)
Food or Forage Uses
Seed – raw or cooked. Low in tannin, it has a sweet flavor. The seed is usually produced in clusters of 3 – 5 and is about 25mm long and 10mm wide. It is about 12mm long according to another report. 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 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. An edible oil obtained from the seed is used for cooking. The roasted seed is a coffee substitute.
Native Americans relied extensively on acorns for food. Years ago, sacks or baskets of acorns were placed in streams to leach the bitter tannins from them.
One large oak tree can produce 1,000 pounds of acorns in a year. Acorns are nutrient dense foods. They are lower in fat and sugars then many other nuts. Acorns provide about 125 calories per ounce. They are rich in polyunsaturated fats, vitamin B6, copper, manganese, and potassium.
Acorns vary in flavor from not bitter to too bitter to eat. Acorns that are produced in one year tend to have a mild flavor while the ones that are only produced every two years are bitter. Oaks that have smooth oval shaped leaves have tastier acorns than those from trees that have pointy lobed shapes. Species that produce acorns with large caps generally yield bitter acorns. Oaks yielding the best tasting acorns include white oak, live oak and swamp chestnut oaks. Red oaks, turkey oaks and laurel oaks produce bitter acorns. Cream colored acorn meats taste best. Acorns with yellow or orange meat are bitter. Individual trees of the same species produce acorns with differing levels of palatability.
Acorns for food use need to be gathered in the fall to avoid bacterial and insect contamination. Throw away any with insect holes in them. All acorns require leaching in order to remove the bitter taste of tannins. Some need just a couple of changes of water while others require several. Acorns can be leeched by either of two methods:
Method 1
Cover the unshelled acorns with cold water. Throw away any that float. As the water turns brown, change it repeatedly. This can take days or even weeks. Using the cold water method is beneficial if you intend to use the acorns as a thickener.
Method 2
Bring a large pot of water to a full boil. Pour in acorns. Throw away the ones that float. As the water turns brown, heat a second large pot of water to boiling. Strain the acorns from the first pot. Place in the second pot. Keep repeating until the acorns are no longer bitter.
To dry leeched acorns, fry them in an un-oiled frying pan, stirring frequently, or place them in a 150-200 degree oven for about 20 minutes. They can also be spread on a screen in a single layer to air dry for several weeks.
Store the acorns in a sealed container. They will keep for about 6 months. When you are ready to use the acorns, crack them open with a nut cracker. Acorns stay fresher if shells are not removed until you are ready to use them.
To make acorn flour, place the shelled acorns in a blender and process until fine. Store the flour in a cool dark place. It keeps well in the freezer. Use acorn flour as a nutritious substitute for flour. In baked goods; do not substitute more than one fourth to one half of the regular flour in a recipe with acorn flour. The acorns can be kept in larger pieces and used like any other nut.
Medical Uses
Oaks were used as medicine and food for millennia. Many Native American groups used oak to treat bleeding, tumors, swelling and dysentery. European herbalists used oak as a diuretic and as an antidote to poison. Snuff made from powdered root was used to treat tuberculosis. The leaves have been employed to promote wound healing. Oak has been used as a Quinine substitute in the treatment of fevers.
Tannins provide many of the healing properties of oak. Tannins bind with proteins in tissues, making a barrier resistant to bacterial invasion. Tannins strengthen tissues and blood vessels. They reduce inflammation and irritation, especially of skin and mucus membranes.
Modern scientific research confirms that oak possesses the following healing properties: astringent, fever reducing, tonic, antiseptic, anti-viral, anti-tumor, and anti-inflammatory actions. In addition, oak has been used to get rid of worms and other parasites.
The plant parts used for healing include the inner bark, leaves and acorns.
Oak is excellent for controlling loose stools. Either a tincture (alcohol extract) or decoction (boiled tea) of root bark is effective. Decoctions are used to promote healing of bleeding gums when used as a mouthwash. Finely powdered dried inner bark has been used to control nosebleeds. Oak is said to relieve poor digestion. It has been used to treat ulcers internally and externally. Finely powdered dried inner bark can be sprinkled on external ulcers to soothe, reduce swelling, prevent infection, and strengthen tissue. A decoction or tincture can be used to heal internal ulcers. Compresses made from a root bark decoction soothe and shrink hemorrhoids, varicose veins, and bruises. A bark decoction can be used as a gargle to relieve a sore throat. Skin problems such as rashes, irritation and swelling may be relieved with the application of poultices or compresses made from the root bark or leaves. Oak has been used in the treatment of cholera and gonorrhea. Decoctions have been used as douches to treat vaginal infections
Leaves may be used fresh for first aid in the field. They can be softened by immersing them in boiling water or steaming until limp. If boiling water is not available, the leaves may be softened by crushing them. Apply the leaves topically to the affected area as an antiseptic, soothing poultice to reduce swelling, skin irritation or bleeding.
Acorns are soaked to remove tannins prior to using the acorn meat for food. The tannin rich soaking water has antiseptic and anti-viral properties. It may be used as a wash to relieve skin irritations from rashes, minor burns and poison ivy.
To prepare a decoction of oak, use 1 teaspoon of dried inner bark per cup of water. Simmer the herb and water, covered, for 20 minutes. Strain the herb from the liquid before using the decoction. If using internally, drink 1 cupful of the decoction 3 times daily. However, if the decoction is being used to relieve loose stools, drink one-fourth cup after each loose stool.
If preparing a tincture, use a spirit that contains 60 percent alcohol. Herbalists recommend that 1-2 milliliters may be consumed three times daily.
Fresh leaves may be gathered for first aid as needed. The inner bark is the most useful medicinal part of the oak. It is bitter and astringent in taste. The inner bark is best gathered in spring from roots protruding through the ground. Dry it and store the bark in a cool dark place. Acorns are gathered in the fall.
Oak bark combines well with chamomile for soothing the digestive system. Do not use oak for people who suffer from constipation. Oak is not recommended for large open wounds or for treatment of weeping eczema.
Other Uses
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 bark is a commercial source of tannin. Dyes of various colors can be obtained from the bark. Wood – very heavy, hard, strong, tough, close grained but difficult to work. It weighs 59lb per cubic foot. It is used for making hubs, cogs, shipbuilding etc. A very good fuel.