Holly Oak, Evergreen Oak
Quercus ilex
Family: Fagaceae
What it is like
Bloom Color: Brown. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Rounded.
Quercus ilex is an evergreen Tree growing to 25 m (82ft) by 20 m (65ft) at a slow rate. See above for USDA hardiness. It is hardy to UK zone 7. It is in leaf all year, in flower from May to June, and the seeds ripen from September to 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: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline and saline soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil. The plant can tolerate maritime exposure.
Height (m): 25
Where it is found
Arid places, maquis, woods and hills on limestone.
Europe - Mediterranean. Occasionally naturalized in Britain in S. England.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 5
Seed - raw or cooked. It can be sweet or bitter. The seed is up to 3cm long, 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 from some trees 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. An edible oil is obtained from the seed. One reader noted the Q. suber population of the Mamora forest in Morocco contains only sweet acorns and can be eaten raw, it has a similar taste to raw chestnuts. The skin removes quite easyl Quercus ilex also exists with tannin-free acorns in the moroccan forests, the locals say around 20 percent are sweet.
Oil: Oil
Seed: includes nuts, cereals, peas and beans.
Coffee: the various substitutes that can be used instead of coffee.
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.
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.
Other
Rating: 3
Landscape Uses: Specimen, Street tree. 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. Very tolerant of maritime exposure and of trimming, it can be grown as a shelterbelt tree or hedge in maritime areas. Wood - strong, hard, durable. Used for furniture. It makes a good charcoal and a good fuel, burning well even if green. The bark is a source of tannin. Heat Zone: 9-2.
Fodder: Food given to the animals (including plants cut and carried to them) rather than forage for themselves.
Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.
Hedge: Plants that can be grown as hedges.
Oil: Vegetable oils have many uses, as lubricants, lighting, soap and paint making, waterproofing etc. This does not include the edible oils unless they are also mentioned as having other uses.
Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.
Shelterbelt: Wind resistant plants than can be grown to provide shelter in the garden 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.
Fodder: Mast: Fruits and seeds of shrubs, woody vines, trees, cacti, and other non-herbaceous vegetation available for animal consumption.
Industrial Crop: Tannin: Occur generally in the roots, wood, bark, leaves, and fruit of many plants. Used in tanning leather, dyeing fabric, making ink, and medical applications.
Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.
Other Systems: Dehesa: A fodder tree silvopasture system with livestock grazing on tree crops - nuts, fruit, acorns, woody pods, fodder.
Regional Crop: These crops have been domesticated and cultivated regionally but have not been adopted elsewhere and are typically not traded globally, Examples in this broad category include perennial cottons and many nuts and staple fruits.
Staple Crop: Balanced carb: (0-15 percent protein, 0-15 percent oil, with at least one over 5 percent). The carbohydrates are from either starch or sugar. Annuals include maize, wheat, rice, and potato. Perennials include chestnuts, carob, perennial fruits, nuts, cereals, pseudocereals, woody pods, and acorns.
Fodder: Mast: Fruits and seeds of shrubs, woody vines, trees, cacti, and other non-herbaceous vegetation available for animal consumption.
Industrial Crop: Tannin: Occur generally in the roots, wood, bark, leaves, and fruit of many plants. Used in tanning leather, dyeing fabric, making ink, and medical applications.
Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.
Other Systems: Dehesa: A fodder tree silvopasture system with livestock grazing on tree crops - nuts, fruit, acorns, woody pods, fodder.
Regional Crop: These crops have been domesticated and cultivated regionally but have not been adopted elsewhere and are typically not traded globally, Examples in this broad category include perennial cottons and many nuts and staple fruits.
Staple Crop: Balanced carb: (0-15 percent protein, 0-15 percent oil, with at least one over 5 percent). The carbohydrates are from either starch or sugar. Annuals include maize, wheat, rice, and potato. Perennials include chestnuts, carob, perennial fruits, nuts, cereals, pseudocereals, woody pods, and acorns.
Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
Hedge: Hedge
How it is grown
Prefers a good deep fertile loam which can be on the stiff side. Thrives on shallow chalky soils. Succeeds in all soils except those that are cold and poorly drained. Grows well in sandy soils. Young plants tolerate reasonable levels of side shade. Very resistant to maritime exposure. A very ornamental tree but it is quite slow-growing. Transplants badly unless moved regularly and this should be done as growth commences in late May or in September. Fruits very freely in Britain. The seed ripens in its first year. The sub-species Q. ilex ballota is cultivated for its sweet-tasting edible seed in Portugal and Spain. Hybridizes freely with other members of the genus. This species is notably resistant to honey fungus. Special Features: Not North American native, Inconspicuous flowers or blooms. The plant is heat tolerant in zones 9 through 2. (Plant Hardiness Zones show how well plants withstand cold winter temperatures. Plant Heat Zones show when plants would start suffering from the heat. The Plant Heat Zone map is based on the number of "heat days" experienced in a given area where the temperature climbs to over 86 degrees F (30°C). At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 (no heat days) to 12 (210 or more heat days). For example Heat Zone. 11-1 indicates that the plant is heat tolerant in zones 11 through 1.) For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is a standard with a non-suckering single trunk.
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; Hedge;
Habit: Tree
Hardiness: 4-10
Growth: Slow
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist