Ash Tree Identification (With Pictures)


Ash Tree

Ash tree is very famous in the northern parts of Europe, Asia, and North America. It is a deciduous tree that belongs to the family of Oleaceae and genus Fraxinus. In all, there are 50 -60 different species of Ash tree.

Ash tree grows well in well-drained moist soil. Also, it is comfortable in a cool and warm climate. However, it does not require direct sunlight.

How do I identify an Ash tree?

The Ash tree is usually a large, well-spread tree with lots of leaves. You can identify the Ash tree by its leaves, branches, bark, and the seeds.     

One very prominent feature that you can notice in the Ash tree is the arrangement of the leaves, which is precisely opposite to one another on the branches. Similarly, its branches are also located opposite to one another on the tree. This symmetrical distribution of the leaves and the branches will surely catch one’s attention.

Ash Leaves

The leaves are compound with an even number of leaflets. Generally, the leaflets are 5, 7, or 9. These tiny leaflets typically arranged opposite one another, with one of it making up the tip. And hence the leaflets are always in an odd number.

The leaflets are round at the base with a prominent tip and irregular serrations on the sides. If you notice carefully, you would realize that the leaflets do not have any stem. You will find these directly connected to the mid-rib of the leaf. The leaflets have a dual shade of very bright and vibrant green on the top and a lighter shade of green on the underneath.

The other identifying feature is the bark of the tree. In the case of a young Ash tree, the bark is very smooth and is greyish like the twigs. As the tree grows a little older, the bark color changes to beige-grey. The bark of the fully-grown tree is rough with furrows, which is cut precisely into diamond shapes. The color of the bark also changes to a mature dark grey.

Ash Tree Bark

The Ash tree grows very tiny purple color flowers, which are very difficult to notice. But after the flowers have bloomed, the seeds come in clusters. Because of its peculiar shape, the seeds are usually known as ‘Keys.’ The seeds have one wing, and it flies down like a helicopter. The cluster of keys is green in the beginning, and by the middle of the autumn, it turns brown. The brown color seed cluster is very prominent to the sight when all the leaves drop down during the autumn.

Out of the wide variety of Ash trees, the most common is the black, blue, white, and green Ash.

The White Ash (Fraxinus americana)

White ash

Generally, this is prevalent in the Eastern USA. It usually grows to a height of 80 feet and produces purple-green flowers. The fresh green leaves turn yellow and then stunning purple-red before these finally wither. It adds beautiful color to the landscape.

Green Ash (Fraxinus pennsylvanica)

Green Ash

It is comparatively a fast-growing variety of Ash tree that reaches a height of 70 feet. It is quite similar to the white Ash in looks. Unlike the White Ash, flowers appear after the leaves in the case of Green Ash. It has a well-shaped round crown, which looks very attractive with yellow leaves in the autumn.

Black Ash (Fraxinus nigra)

Black Ash

The black Ash is slow-growing as compared to the above two varieties. It is resistant to wetter soils and conditions and develops leaves in the late spring. Black Ashwood is softer than the white and green Ash tree wood.

Blue Ash (Fraxinus quadrangulata)

Blue Ash

Black dye gets extracted from the bark of this Blue Ash, which finds use in textile dyeing. It is usually a medium-sized Ash tree growing to a height of 35 to 75 feet. The twigs of the Blue Ash have four prominent ridges and hence the name ‘Quadrangulate.’

How fast do Ash trees grow?

The Ash tree has a moderate to fast growth rate. The average growth rate is around 2 feet/year.

However, different species may have a different growth rate. The growth also depends significantly on the growing conditions. Ash trees planted in a row, exhibit slower growth rate.

Most of the Ash trees grow 18 to 25 feet in a decade. But there are also some species like the European Ash (Fraxinus excelsior) that reach less than 18 feet in 10 years.

The average mature height of the Ash tree is between 40 -60 feet, with some reaching up to 80 feet also. Depending upon the species, it may take 16 -60 years for the tree to reach its mature height. The velvet Ash, on the one hand, has a final height of 30 feet as against 120 feet of white Ash.

A Medium-sized Ash tree grows comparatively fast with the average growth rate of little more than 24 inches/year.

What does the bark of an Ash tree look like?

The bark of the Ash tree usually looks different at different stages. As a very young Ash tree, it will have a very smooth trunk with a grey color. But as it grows a little more, the color changes to beige-grey and the bark matures. You can feel the roughness coming as the smooth feel is completely gone.

As the tree grows and matures, the bark gets formed completely. It also has a unique character, like the deep vertical furrows formed on the surface. And it conspicuously creates diamond shapes. Even from a distance, you can easily make out the diamond shapes in its furrows.

Do all Ash trees have seeds?

Ideally, the Ash trees are dioecious by nature. That means the tree can be either a female tree or it can be a male tree. It will not have both parts in one tree.

That being the case, only the female Ash trees will have seeds. The male Ash trees will not bear the seeds or the fruits (samaras). So, if you are looking out for an Ash tree that will not litter your space, opt for the male Ash tree.

The Ash tree develops black buds even before the onset of the leaves in spring. If these buds give out purple flowers with a short stalk that grows horizontally, then the tree is identified as a male tree.

In the case of the female tree, these buds will produce purple flowers with a long stalk, and the flowers will grow upright.

You can see the dark-colored Ash galls only on the male Ash trees.

What do the seeds of an Ash tree look like?  

The seeds of the Ash tree are inside the samara that is flat oar shaped and generally called as the helicopter keys. The seeds are in the thicker end of the samaras.

Ash Tree Seeds

The samaras have a single wing, and when dislodged from the tree, they come down swirling like a helicopter hence, also called the helicopter keys. These seeds always come in bunches.

These are green when young and immature. On maturity, the color turns to yellow and then brown.

The seed clusters become very prominent on the tree when all the leaves fall off the branches during the fall season.

Where do Ash trees grow best?

The Ash trees grow well in the USDA zones 2 -9. They can tolerate a shortage of water. But need a comparatively cool climate. The soil should be moist and well-drained. For proper growth and development, it needs good sunlight.

Since the Ash tree grows to about 40 -80 feet, plant it at a reasonable distance from the construction.

Ideally, acidic soil is better for the Ash tree with pH rating from 4 to 7. If the pH rate is not within the range, appropriate amendments to the ground can bring the desirable pH.

If possible, locate a site where the leaves and the top of the tree receive proper sunlight, but the soil is in the shade. This location is to preserve the moisture of the ground.

If you propose to plant an Ash tree that you got from a nursery, dig a hole at least twice as wide as the roots and one foot more than the height of the root ball. After planting the tree, do not hard compact the soil. Loose and well-aerated soil will help the Ash tree establish and settle soon.

It has good tolerance to seasonal and occasional waterlogging.     

What is the general lifespan of an Ash tree?

The average lifespan of the Ash tree is around 120 years. However, certain varieties have lived as long as 175 years.

This lifespan was the case in the 20th century when the Ash trees got planned and planted very systematically.

However, in the year 2002, the EAB (Emerald Ash borer) stuck the Ash tree in the USA. These beetles inadvertently entered the USA with some pallets imported from Asia. The fluorescent beetles eventually created havoc for the Ash tree.

In about the last 15 years, more than 25 million Ash trees have succumbed to the attack of the EAB. Since then, it has not been possible to control the EAB. Once infected, it kills the tree in a span of one to five years.

With this deadly EAB on the prowl, determining the lifespan of the Ash tree is very difficult. The EAB attack at any time can destroy any Ash tree.

There were trials in the treatment in the form of injection and the liquid application, but the effect is minimal.       

How do you take care of an Ash tree?

Once you have planted the Ash tree, water it when needed, apply mulch, fertilize once in a year, and also protect it from diseases and pests. Doing all this will amount to taking good care of the Ash tree.

Once a week, try to deep water the Ash tree with a slow trickle of water. Watering in this way will reach deep in the soil and keep it moist for a long time. Superficial or surface watering does not last long. It evaporates and dries very fast.

Spread organic mulch at least 4 inches thick all around the Ash tree. Keep the mulch a little away from the central trunk. Mulch not only supplies nutrients to the tree but also keeps the soil moist for a long time. It also keeps the ground cool.

Once a year, during the fall, apply an all-purpose 10-10-10 fertilizer to the Ash tree. Ensure that the Ash tree is perfectly healthy and looks right before fertilizing. Avoid fertilizing a sick or depressed tree.

Some common disease that afflicts the Ash trees are:

1.     Emerald Ash borer:

This disease is the most deadly and fatal attack on the Ash tree. If infected, there is no treatment to treat the Emerald Ash Borer.

The tree consequently loses its health, and leaves along with branches start falling. The beetle lodges itself under the bark and eats into the tree. You can see tunnels dug up all under the bark.

2.     Other wood borers.

Apart from the EAB, other wood borers can hurt and damage the Ash tree. But interestingly, these borers do not harm a healthy tree. Only if the tree is damaged or stressed, the borers take advantage of the reduced immunity of the tree and attack it.

Therefore. You must always keep the Ash tree healthy by watering it well and feeding it with proper nutrients.

3.     Also, the anthracnose, wilt or rust can afflict the Ash tree.

Try to maintain the right growing conditions for the Ash tree. Avoid planting other trees very close to the Ash tree. Remove the undergrowth and let the roots of the Ash grow unhindered.

Why is bark falling off my Ash tree?

Bark falling off from the Ash tree may be because of environmental problems or external conditions, or it could be because of some disease that has attacked the tree. Either way, you should take cognizance of the issue and resolve it in the best possible manner. This careful approach will avoid any severe impact on the Ash tree.

All those Ash trees which grow near water bodies acclimatize to a good supply of water. If during the summer, the water to the Ash tree reduces, it stresses the tree. As a consequence, the tree starts shedding the bark.

To manage this situation, immediately deep water the tree and keep doing that once in 7 to 10 days.

Another reason for the bark shedding is the excess pruning of the lower branches. Removal of the lower branches exposes the trunk and bark of the tree to direct sunlight. Consequently, the bark gets ‘sunburned’ and sheds itself because of it. The exposed trunk is very dangerous to have because the EAB can get onto it and bore its way inside to destroy the tree.

To prevent this condition, apply a trunk wrap or paint the exposed part of the trunk with white latex paint. Before dressing it, look out for the typical D type tunnel of the EAB.

The worst reason for the Ash tree to shed its bark is the attack of the EAB. If the infliction is severe, it will kill and destroy the plant eventually.

A large tree falling because of EAB infestation can destroy nearby trees and any construction around the place. Therefore, the best thing to do in such a situation is to bring down the tree with the help of an arborist.

How do I know if my Ash tree is dying?

Discolored leaves, lesions on the leaves, and dropping of leaves and branches are a sure sign of the Ash tree dying.

If the Ash tree is on the way to death, it will start to look pale and listless. The foliage will lose its glow. You can see orangish or dark brown lesions on several leaves. The lesions appear at the base of the leaf blades, the stems, and the leaves wilt and dry off.

The Ash dieback is called Chalara and is due to the fungus Hymenoscyphus fraxineus. This fungus found its way into the USA and Europe from Asia.

Ash dieback

Apart from destroying leaves and the stems, it weakens the whole tree to a large extent and can turn fatal for the tree.

A weakened Ash tree is a host to several other pests, insects, and infections. All these will gradually kill the Ash tree.

Lindsey Glenn

I've been learning about gardening since 2015, helping friends and family to grow their trees. I am passionate about trees and love sharing everything I learn about them.

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