- Plant Database
- h2g2 The Hitchhiker’s Guide to the Galaxy: Earth Edition
- Environmental Studies
Fraxinus excelsior – Common Ash
The common ash belongs to the family of olive trees. With stature heights of about 40 meters (132 ft), the ash tree is one of the tallest deciduous trees in Europe. Due to the very good wood properties, the ash is added to the noble hardwoods. In 2001, the common ash tree was voted tree of the year.
After about 100 years Fraxinus excelsior reaches a stature height of about 30 meters (99 ft) and a trunk diameter of up to two meters (7 ft). The trees can grow up to 300 years old. Characteristic is a straight trunk axis without bifurcations. The sprouting of the trees takes place completely in the bud of the previous year. Young trees occasionally possess enrichment shoots. Furthermore, linear drives are formed.
The buds of the common ash are black, conical and shaggy hairy. The felted hair serves as protection against frost and evaporation. The end buds are much larger than the buds on the twig. The buds are finished at the end of July.
The bloom of the common ash begins in May. These are small, inconspicuous flowers without perianth. The ovary is greenish and is formed from two carpels. The dust bags on two short stamens are initially purple. As the sole representative of the olive trees, the common ash is pollinated by the wind.
The nut fruits appearing in September and October become up to 3.5 cm (1.4 inch) long and are narrow and oblong. The shiny brown fruits often remain on the tree until the autumn of the following year. The winged nuts are counted as helicopter flyers and the dropped nuts can cover distances of up to 100 meters (333 ft).
Ash wood is very valuable and can be processed well. The hardwood has good mechanical properties. The surface can be easily edited. For outdoor use, however, ash wood is rather unsuitable because it proves to be less weather-resistant and begins to rot easily when in contact with the ground. In the living area, the wood of the ash is used for veneers. Also garden tools or gymnastic equipment are made of ash wood.
- native to Europe
- hardy to zone 5
Habit and Form
- a large deciduous tree
- 60′ to 80′ tall
- generally wider than tall
- dense rounded crown
- medium texture
- fast growth rate
- opposite leaf arrangement
- odd, pinnately compound leaves
- leaves are up to 1′ long
- leaves contain 7 to 11 leaflets
- leaflets are ovate shaped
- leaflets are 2″ to 4″ long
- serrated leaf margins
- medium green leaf color
- no fall color, leaves drop green
- some cultivars have yellow fall color
- greenish flowers
- bloom in spring
- not showy
- female plants produce samaras
- samara is green and elongated
- 1″ to 2″ long
- clustered in bunches
- turn brown in winter
- not ornamentally important
- branches low on trunk
- grayish brown bark
- young stems are gray and stout
- full sun
- soil tolerant
- salt tolerant
- needs regular pruning
- prefers moist, deep, fertile soils for best growth
- soil pH is not critical
- easily transplanted and established
- male plants are preferred for landscape purposes
- lawn tree
- shade tree
- difficult growing sites
- excellent for parks and campuses
- female trees produce lots of seed, leading to numerous unwanted seedlings
- fruit can also be a litter problem
- ash dieback (mycoplasma)
- ash borers
- ash flower galls (male plants) caused by a mite
- ash yellows
- opposite leaves
- pinnately compound leaves
- female plants with paddle-shaped samaras
- black, pubescent, sessile buds
- twigs gray and buds brown
- twigs stout
- by bud grafting
- by seed
Though many cultivars are recorded in the literature, they are very rarely available in this country. Our native ashes predominate in commerce.
‘Hessei’ – The most commonly available European ash, this plant grows quickly to 60′ tall with an oval-rounded habit. The leaves are simple and bear prominent marginal serrations. Testing indicates, however, a strong tendency for borer damage in this country.
White Ash (Fraxinus americana)
The white ash is the most common ash species found in North America. It is a tall, straight tree with a conical or rounded crown of foliage. The white ash has compound leaves that are made up of five to nine (usually seven) leaflets. Each leaflet is eight to twelve inches long and is oval to oblong in shape with very fine, saw-toothed edges. The leaflets are arrayed opposite each other and are dark green above and whitish-green below. This pale undersurface is visible even from the forest floor whenever a breeze ruffles through the crown of the ash tree.
Bark, Flowers and Seeds
The bark of the white ash is gray and is finely furrowed into close, diamond shapes. The bark on young trees may also have a tint of orange. The white ash flowers in the early spring. An individual tree will have either male or female flowers. The fruit that forms on the female trees is a one-seeded samara (seeds plus a ‘wing’ to aid dispersal) that falls in the late summer or early autumn. The samara are one to one and half inches long, brown and have a pointed, lance-like shape.
White ash seedlings grow well in the shaded conditions of the forest floor and are capable of very rapid growth. A seedling may reach a height of six feet, for example, by the end of its third growing season.
The wood of the white ash is very dense and strong. The tree trunks and branches resist breakage from winter ice buildup or from windstorms. Looking around the white ash area of the Nature Trail you will see very little downed wood or broken trees. White ash makes excellent firewood and is used to make baseball bats, hockey sticks, tennis rackets and many other items that require a strong, resilient wood.
h2g2 The Hitchhiker’s Guide to the Galaxy: Earth Edition
The common ash tree of Britain and Ireland is the species Fraxinus excelsior, whose range actually covers most of Europe. There are many related species of Fraxinus found in other parts of the world, while the Rowan, or Mountain Ash, is a smaller tree from a different family.
The ash tree can grow to a height of 30m, with a spread of 20m. It is deciduous, with leaves which are divided into 9-13 leaflets whose proper botanical shape is termed pinnate. These leaves give the tree a feathery outline in summer, and a yellow colour in autumn.
The bark on the trunk is a greyish brown, with deep cracks, but the bark on the younger twigs is a smooth, pale, greenish-grey, which gives a strong contrast in winter to the matt black buds. The distinctive black colour of the buds makes the ash very easy to identify in winter. The buds are often the last to open in the British spring.
Clusters of small green flowers appear in spring, before the leaves. Most flowering plants have flowers that contain both male and female parts, while some produce separate male and female flowers on different plants. The common ash is seriously confused in this respect: while some ash trees have flowers with both male and female parts, some have only male or only female flowers, and some produce separate male and female flowers on different branches. Some branches which produce only female flowers one year may produce all male flowers the following year. The end result of this mixed-up sex is normal enough – flowers with female parts produce bunches of dry seeds1 known as keys.
Germination and Growth
The seeds, or keys, stay on the trees through the winter, and only fall in spring. They can be carried long distances by the wind, and germinate quickly in almost any type of soil. In European conditions the ash is normally a fast-growing tree, and will start flowering when around 30 years old, when it will probably have reached a height of 15 to 20m. Growth in height will usually stop when the tree is around 100 years old. Very few ash trees live beyond the age of 250.
The Habitat of the Ash Tree
Ash trees grow best on fairly damp soils, as long as the conditions are not too acidic. Since they need plenty of light, they can easily be crowded out by other overshadowing trees. The limestone areas where they flourish also suit beech trees, so that long-lasting ash woodland is usually found only in areas outside the range of the beech. In Britain, ash woodland can be found on the steep limestone slopes of the Peak District, in Somerset, in South Wales, and in southwestern Scotland. In Ireland, where the beech tree is not a native, the old forests in limestone areas were once a mixed woodland of ash and elm. Most of these forests were cleared long ago, but the ash is still the most common large tree in Irish lowland hedges.
Ash trees do not support a wide range of invertebrates2. This means in turn that ash woodlands do not have as rich a collection of birds as most other broadleaved forests, though chaffinches, wrens, blackbirds and robins can usually be found.
Ornamental Varieties of the Common Ash
If given the room to grow and spread, the common ash forms a very striking specimen tree, though the lack of undergrowth makes it unpopular among many gardeners. There are also a number of cultivated varieties, which may be found in large gardens and country parkland. These include Fraxinus excelsior ‘Jaspidea’ which has yellow leaves in spring, and a golden colour in autumn, and the smaller weeping ash, Fraxinus excelsior ‘Pendula’.
The Uses of Ash Wood
Ash wood has two main practical uses. It is excellent firewood, and burns well even before being dried. In many areas, ash trees were traditionally coppiced for firewood. This meant that the branches were regularly chopped back so that the plant took the form of a bush rather than a tall tree.
The other main use of ash wood is when both strength and a little flexibility are needed. In sports, ash is commonly used for hockey sticks, oars, snooker cues and for the hurleys used in the Irish sport of hurling. ‘The clash of the ash’ is a familiar phrase to Irish sports journalists trying to convey the excitement of a hurling match. Ash wood is also popular for tool handles. Its shock-absorbing quality makes it useful for the chassis frames of the classic Morgan motor cars. It was also widely used for making longbows.
Mythology and Folklore
The ash was quite an important tree in many older European traditions. Its English name is said to come from the Anglo-Saxon word aesc, meaning spear. In Norse mythology, the World Tree Yggdrasil was an ash tree. In the Celtic Ogham Alphabet ash or ‘Nion’ represented our modern letter N. In English folk wisdom, it was thought that the opening of the buds could predict the weather: if oak buds were seen to open first, the summer would be dry, while if the ash buds opened first, the weather would be wet. This can be remembered by the little rhyme:
Oak before ash, in for a splash
Ash before oak, in for a soak. 1Technically these are actually fruits, but this causes confusion to those who assume that fruits are edible.2These are the legless worms, slugs and snails, and many-legged insects and spiders that are less technically known as ‘creepy-crawlies’.
White ash (Fraxinus americana), also called Biltmore ash or Biltmore white ash, is the most common and useful native ash but is never a dominant species in the forest. It grows best on rich, moist, well-drained soils to medium size. Because white ash wood is tough, strong, and highly resistant to shock, it is particularly sought for handles, oars, and baseball bats.
The White ash is resistant to heat, although it is native to moist locations, including river bottoms and well-drained upland sites. It grows 50 to 80 feet tall and wide. The trees produce a good seed-set every two to three years and they germinate in the landscape creating a nuisance and perhaps look a bit messy. The seeds are used by many birds and can be produced in countless numbers. The tree grows rapidly and is almost pyramidal when young, but gradually slows down and develops a more spreading round or oval shape. White Ash prefers a sunny exposure where it develops a showy yellow fall color. Fall color can be striking or dull, depending on the tree and environmental conditions.
Leaf: Leaflets are often ovate (egg-shaped). The leaves are whitish (glucose) beneath. This tree contains opposite pinnately compounded leaves.
Flower | Seeds: Flowers appear in early spring. These are male flowers. White Ash is dioecious which means the male and female flowers are on different trees. The samaras (fruits) have long, narrow wings. Buds are rich brown with an interesting scaly texture.
Twig: Stout, gray-olive-green, hairless, leaf scars round at the bottom, notched at the top, with lateral buds in the notch; terminal bud is large, brown, with leathery scales and flanked by two lateral buds.
Trunk | Bark: The bark of larger trees usually has diamond-shaped intersecting ridges.
Form: A large tree up to 80 feet tall that typically develops a straight, clear bole (particularly on good sites), usually with a narrow oblong crown.
Life span: Perennial – a plant that lasts for more than two growing seasons.
The White Ash is best grown in moist, organically rich, well-drained loams in full sun. Moderate drought tolerance. Best sited in locations protected from strong winds. Generally tolerant of urban conditions, particularly if well-sited in the landscape. Tolerant of neutral to slightly alkaline soil conditions.
Native Range: White ash grows naturally from Cape Breton Island, Nova Scotia, to northern Florida in the east, and to eastern Minnesota south to eastern Texas at the western edge of its range.
Climate: The climate varies greatly within the natural range of this species. The length of the frost-free period is from 90 to 270 days. Mean January temperatures range from -14° C (7°F) to 12° C (54° F) and the mean annual minimum temperatures range from -34° C (-30° F) to -5° C (23° F). Mean July temperatures range from 18° C (64°F) to 27° C (81° F). The average annual precipitation is between 760 and 1520 mm (30 and 60 in), and the snowfall is from 0 to 250 cm (100 in).
Elevation: White ash grows from near sea level on the Coastal Plain to
3,450 feet (1,050 m) in the Cumberland Mountains.
Soil: White ash has a strong affinity for soils high in nitrogen and
Importance to the ecosystem
Seeds of White Ash are eaten by several species of birds. The bark is occasionally food for rabbits, beavers, and porcupines. Cavity excavating and nesting birds often use White Ash. This tree attracts wood ducks, bobwhites, purples finches, pine grosbeaks, fox squirrels, rabbits, beavers, mice, and porcupines.
The damage to the ash population will be economically and ecologically devastating. It has the potential to wipe out the whole species, which could seriously affect ecosystems. In addition, the ash tree is an important economic factor not only by the popularity in the purchase of the tree for ornamental planting but for the products made and sold from its wood. In addition, the cost of removing dead or dying trees is overwhelming municipal budgets. Homeowners must also pay to either prevent the disease or to eliminate diseased trees from their properties.
Relationship with other species
Non-human: White ash is an important source of browse and cover for livestock and wildlife. The samaras are good forage for the wood duck, northern bobwhite, purple finch, pine grosbeak, fox squirrel, and mice, and many other birds and small mammals. White ash is browsed mostly in the summer by white-tailed deer and cattle.
White ash’s ability to readily form trunk cavities if the top is broken
and its large d.b.h. (24 to 48 inches ) at maturity make it
highly valuable for primary cavity nesters such as red-headed,
red-bellied, and pileated woodpeckers. Once the primary nest excavators
have opened up the bole of the tree, it is excellent habitat for
secondary nesters such as wood ducks, owls, nuthatches, and gray
Humans: The durable wood is used to make tool handles, oars, canoe paddles, baseball bats, furniture, antique vehicle parts, snowshoes, cabinets, railroad cars and ties, etc.
Pests: Borers are common on Ash and they can kill trees. The most common borers infesting Ash are Ash borer, lilac borer and carpenterworm. Ash borer bores into the trunk at or near the soil line causing tree dieback. Lilac borer causes swellings on the trunk and limbs where the insect enters the tree. The carpenterworm larvae bore into the heartwood but come to the outside of the tree to push out frass and sawdust. Heavily infested trees can be severely weakened. Keep trees as healthy as possible by fertilizing regularly and watering during dry weather.
Aphids are often seen but are usually not serious.
In late summer, fall webworm covers branches with webbing. The nests in branches close to the ground can be pruned out when first noticed. Bacillus thuringiensis may control fall webworm.
Diseases: A rust disease causes distorted leaves and swollen twigs. Small, yellow, cup-like structures, producing yellow spores, appear on the infected areas. Controls are usually not needed.
A number of fungi cause leaf spots on Ash. The disease is worse in wet years and is partially controlled by gathering and disposing of diseased, fallen leaves.
Anthracnose is also called leaf scorch and leaf spot. Infected parts of the leaves turn brown, especially along the margins. Infected leaves fall prematurely. Rake up and destroy infected leaves. Chemical controls are not practical or economical on most large trees.
Canker diseases cause branch dieback and death of the tree when the trunk is infected. Try to keep trees healthy with regular fertilization.
Powdery mildew makes a white coating on the leaves.
Ash ring spot virus causes chlorotic red and yellowish spots or rings on the leaves. Infected trees may be stunted and dieback, but often the problem in minor.
Verticillium wilt causes branches of infected trees to wilt and die, eventually the entire tree may die. Keep trees healthy and fertilize infected trees to suppress disease symptoms.
Other interesting facts
- Some of the primary associates of white ash include eastern white pine (Pinus strobus), northern red oak (Quercus rubra), white oak (Q. alba), sugar maple (Acer saccharum), red maple (A. rubrum), yellow birch (Betula alleghaniensis), American beech (Fagus grandifolia), black cherry (Prunus serotina), American basswood (Tilia americana), eastern hemlock (Tsuga canadensis), American elm (Ulmus americana), and yellow-poplar (Liriodendron tulipifera).
- Almost 99 percent of the fruits (samaras) contain one seed and about 1 percent contain two.
- One of the earliest reported uses of white ash was as a snake bite preventive. Ash leaves in a hunter’s pocket or boots were “proved” to be offensive to rattlesnakes and thereby provided protection from them.
Page Drafted By: Julia Giza