How long do cottonwood trees live

Old Main Cottonwood finds new life through cloning | Colorado Arts & Sciences Magazine Archive

‘Woodman, spare that tree!’ Oh, that’s what you’re doing? Cool!


By Laura Kriho

When the young CU student saw two workers with ropes and helmets getting ready to climb the giant plains cottonwood tree outside of Old Main, terror struck her, and a feeling of impending doom grew in her stomach. Were they going to cut down this tree, the oldest and tallest on campus, which had given beauty and shade to the CU community on the Norlin Quadrangle for over 100 years?

She ran across the quad in a panic and confronted the workers. “What are you doing?” she demanded.

“We’re going to clone the tree,” replied Vince Aquino, an arborist with CU-Boulder’s Facilities Management. “We have to climb up into the canopy of the tree to take some cuttings.”

Aquino smiled as he saw the apprehension in the student’s face slowly fade. “Don’t worry,” he reassured her, “we’re not cutting the tree down.

The student exhaled with relief, and her frown gave way to a smile. “I love CU-Boulder!” she exclaimed. She thanked the arborists and skipped off to class, grateful that this magnificent tree would continue to live in the quad, and also appreciative of the fact that her campus cared so much about the trees.



The Old Main Cottonwood is indeed getting new life. In October, cuttings were taken from the canopy of the tree by Facilities Management arborists Aquino and Joel Serafin. (See related video of the cloning above.)




The baby-cottonwood clones are developing roots.



The cuttings were then handed off to the care of Tom Lemieux, manager of the CU Ecology and Evolutionary Biology (EBIO) Greenhouse on 30th Street in Boulder. The cuttings have rooted and will remain in the greenhouse until sometime in 2015, when they will be planted outside. The cuttings will produce a clone: an exact genetic duplicate of the Old Main Cottonwood.

“Plains cottonwoods are actually relatively easy to clone because they naturally propagate by breaking into pieces and falling in the water and then re-rooting elsewhere,” says Aquino.

“It will be an identical genetic clone, without any genetic engineering,” explains Lemieux. “All we do is take cuttings and root them, which is the traditional method of vegetative propagation.”

“They should be ready next spring or early summer,” Lemieux predicts. “I think we’ll have enough cuttings for Vince to plant that genotype in several areas around campus.”












Joel Serafin and Vince Aquino, arborists



Tom Lemieux, manager of the CU-Boulder greenhouse


Plains cottonwoods (Populus deltoides subsp. monilifera) are known as the “pioneer trees of the plains” because of their hardiness and ability to withstand harsh weather conditions. Plains cottonwoods have an average lifespan of 70 years and reach about 60-80 feet in height.

The Old Main Cottonwood is between 135 and 140 years old, 108 feet tall and 19 feet in circumference at the base of the trunk. Thanks to its superior genetics and its proximity to the Anderson Ditch (which has allowed it to consume as much water as it needed), it is now the oldest and tallest tree on campus.

The Old Main Cottonwood, with its above-average age and height, makes it an ideal candidate for cloning.

Old Main, completed in 1876, was the first building on campus. Sepia-toned photographs show it standing tall and alone on a windswept mesa, surrounded by a bleak and arid landscape with nothing but rocks, rabbits and sagebrush. Joseph A. Sewall, CU’s first president, and his wife, Ann, lived in Old Main from 1877 until 1884.

President Sewall was the driving force behind the mission to improve the appearance of the CU campus through the planting of groves of trees. Timothy W. Stanton, who graduated from CU in 1883, recalled Sewall’s endeavors to beautify the campus with trees.

“His tall slender figure with a hoe or shovel guiding the water to the cottonwood trees, some of which he had himself planted around the university, was a familiar sight,” Stanton wrote in “Reminiscences of a University 65 Years Ago.”












The Old Main Cottonwood was planted in 1879 or 1880. An 1879 voucher from the CU archives showed the university spent $35 out of its general fund for 42 plains cottonwoods, which had a one-year warranty.

In 1880, a second voucher showed the university purchased 43 more cottonwoods, at a price of only $17.50, suggesting that some of the first batch of cottonwoods planted might not have survived.

In 1888, faculty members and students started the tradition of planting trees on campus every Arbor Day, an annual tradition that continues to this day. In 2011, CU-Boulder officially became a “Tree Campus USA,” a designation awarded by the Arbor Day Foundation to recognize CU’s outstanding commitment to trees on campus.

The grove of cottonwoods that used to surround Old Main has dwindled over the years, as the trees have succumbed to age and died, but the Old Main Cottonwood continues to thrive on the south side of the building. However, at almost twice the average age of a plains cottonwood, its days may be numbered.

“It’s a huge, beautiful, majestic tree, and it’s got remarkable health for its age and species, but we have to keep a close eye on it because it’s quite old,” says Aquino.

With cottonwoods, there is the danger that falling branches might cause property damage or harm people on the ground. “It’s a species that grows very quickly, so it can have very soft wood that is prone to breakage,” Aquino explains.

Safety is the first priority for the arborists on campus. “We don’t cut corners with our risk assessment. When this tree becomes past an acceptable threshold of risk, it will have to be removed. That’s probably going to be within the next five to 10 years. Hopefully, it will be here longer than that, but we have to be realistic about it.”

With dedicated arborists Aquino and Serafin on duty, it’s hard to imagine the Old Main Cottonwood in better hands. “We keep a close eye on this tree. It gets climbed every year by a team of climbers who inspect literally every foot of it to check for defects and decay. We’re hopeful every year to get a clean bill of health, but we have to be realistic, and this tree, unfortunately, is near the end of its lifespan.”

“We do everything we can to keep it around as long as we can,” says Aquino. Now, thanks to the new baby-cottonwood clones taking root in the CU Greenhouse, even after the majestic beauty outside of Old Main eventually perishes, the genetics of this celebrated tree can live on in CU history for many future generations of students to admire and enjoy.


Special thanks to David Hays of the CU Archives for providing the pictures of Old Main below. Thanks also to Harvey Gardiner, former CU archivist, for an article on the cottonwoods in the Carillon (4/20/2001).






Laura Kriho is web and publications coordinator for the College of Arts and Sciences.

Dec. 15, 2014



How Long Do Cottonwood Trees Live?

The eastern cottonwood tree (populus deltoides) typically lives 70-100 years. However, in ideal conditions, its life expectancy can reach anywhere from 200-400 years. The Balmville Tree, for instance, was the oldest living cottonwood in the United States at 315 years old when it was felled in 2015. These long-lived trees are quite common throughout North America. Cottonwoods can come in many varieties including the eastern cottonwood, plains cottonwood, black cottonwood, western cottonwood, lanceleaf cottonwood, and Fremont cottonwood.

Table of Contents

How Long Does it Take a Cottonwood to Mature?

Cottonwoods typically take decades to reach maturity. Plains cottonwood trees, for instance, don’t reach maturity until they are nearly 50. Despite the slow maturation, they are incredibly fast-growing trees, sometimes growing up to 6 feet in height each year. This rapid growth can make for a massive tree in a short time. 

  • Cottonwoods take many decades to mature.
  • A cottonwood tree will experience rapid growth in their first 2–3 decades before slowing down as it reaches maturity.

Mature cottonwood trees tend to be around 90 feet tall (27 meters) at their shortest. The most intense growth rate occurs during the first 25–30 years before slowing down. Unfortunately, this quick growth can lead to weak wood which lowers plant hardiness. The soft wood of a plains cottonwood will be especially susceptible to damage during this growth period.

What is the Oldest Cottonwood Tree?

Cottonwood groves in British Columbia, Canada were found to have multiple trees around 400 years old. To date, this is the longest known lifespan for this deciduous tree in natural conditions. 

  • Cottonwood trees have a maximum lifespan of 400 years.
  • The oldest cottonwoods are found in British Columbia.
  • Old cottonwoods can be a property hazard due to their weak wood.

Old cottonwoods can be dangerous trees. Cottonwoods are already not very resilient and they continue to weaken as they age. Their incredible height means that as they weaken, they can fall and bring down other trees around them. They can also cause massive property damage when they fall. Cottonwoods have shallow roots so it’s very easy for them to come down under light stress.

How Do You Know if a Cottonwood Tree is Dying?

Cottonwoods are prone to numerous health issues. You should regularly check the cottonwood leaf canopy for signs of disease. The biggest threat to cottonwood trees is fungal infections which can sometimes be found at the base of the tree. Here are the main warning signs to look out for when evaluating the health of your cottonwood:

  • When you scrape underneath bark or twigs, there is no green.
  • Your tree develops a pronounced lean in one direction.
  • Trees have peeling bark which cracks or splits easily.
  • Missing branches, missing leaves, or leaf rust.
  • Fungus growing at the base of the tree.

If you catch any or multiple of these signs, your tree may be in distress. Consult a local professional arborist as soon as possible. They can evaluate whether your tree can be saved or if it needs to be cut down.

Are Cottonwood Trees Good for Anything?

As fast-growing trees, a black cottonwood tree makes a great shade tree within a couple of years. They can also make an effective windbreak provided you live in a lightly windy area. Sadly, this is about as much use as you’ll get out of a cottonwood tree.

  • Cottonwoods make great shade trees.
  • Cottonwood lumber isn’t prized but their wood pulp makes for high quality paper.

In terms of timber, cottonwood is considered low quality for lumber. It has an unattractive grain and the wood shrinks and warps easily. This hasn’t stopped it from being used for low-quality needs like pallets or boxes. However, cottonwood pulp is known to make high-quality paper for publishing. 

Should You Cut Down Your Cottonwood Tree?

You should probably cut down your cottonwood tree. While they make for beautiful trees, they have a number of downsides that make them a nuisance to maintain. Allergy sufferers will hate them because they are profuse pollen spreaders. Masses of seeds get everywhere in the spring. These seeds are awful to deal with as their cottony fibers get into everything and are hard to clean out.

  • Cottonwoods have many drawbacks that make them difficult to deal with.
  • Pollen from cottonweed trees can cause allergy issues. 
  • Cottonwoods are prone to disease, and have invasive roots.
  • It may be worth replacing your cottonwood with a lower maintenance tree.

Cottonwoods have potentially invasive roots that help prevent soil erosion but can easily ruin pavement and sewer lines. Property owners may worry that such a tall tree can cause severe property damage if it falls down. Potential damage to public property is the number one reason cities cut down their cottonwoods. Cottonwood catches fungal disease easily and their shallow root system fails to support them.

What is the Lifespan of a Cottonwood Tree?

A mature tree of the cottonwood family can live up to 400 years. However, this is uncommon and you’re more likely to see these trees live for only 70–100 years. Let’s go over the key information we’ve learned about cottonwood trees in this article:

  • Cottonwoods live for around a century but can live longer in the right conditions.
  • The oldest cottonwoods are currently found in British Columbia.
  • Cottonwoods grow rapidly during their first 30 years of life.
  • The quickest way to check if your cottonwood is dying is to check for leaf issues of fungus at the base of the tree.
  • Cottonwoods make great shade trees but have little other value.
  • Cottonwood trees have many drawbacks and you may want to consider cutting yours down.

While majestic cottonwood trees are greatly admired, they are hard to maintain. It’s definitely worth considering getting rid of them in favor of easier to maintain trees. If you do decide to keep your cottonwood, consult your local garden center for tips on preventing fungal infections.

Professor about the life of lindens, the death of poplars and the dangers of light garlands - Moscow 24, 08/21/2017

August 21, 2017, 00:00

Ecology poplars, who can benefit from the destruction of the forests of the Moscow region from the bark beetle-typographer and what kind of trees are better to plant new microdistricts, which will be visited by settlers under the renovation program? Director of the agro-biotechnological department of RUDN University, Associate Professor Valentin Vvedensky told about this in an interview with

Photo: m24. ru/Yulia Ivanko

– Mature trees over three meters tall (large ones) are planted in the city center. Do you think they will be able to survive?

– It is difficult for trees to take root in the city. After several years of life, they begin to get sick and may die if they are not sent for rehabilitation back to the nursery - to fresh air to recuperate. And in their place, plant a healthy tree of the same breed from the nursery.

In the Soviet Union, a tree was planted in a gassed area, and after some time it was dug up and sent back to the nursery for rest

Trees in the aggressive environment of the city can be saved by constant rotation of plants after a few years. This technology was used in the Soviet Union: a large-sized plant was planted in a gassed urban area, and after some time it was dug up and sent back to the nursery for rest. In his place was planted one that had already undergone recovery. For example, this is how they kept blue spruces near the Kremlin. Unfortunately, we have lost this practice. But I hope that the experts will revive it.

– Can growing in tree tubs be natural?

- Of course, this is not normal for a tree, but it is acceptable. It is important to observe the size of the container and the tree itself. If the container is small, the plant may die. As a rule, not simple trees are grown in tubs, but exotic ones that cannot withstand our climate. Therefore, they need to be removed for the autumn-winter period in a winter garden or nursery, where they are restored and brought back to normal.

“Landing in frozen ground is a common technology”

– In the spring, many citizens were worried about the question: “Will the linden trees on Tverskaya Street, which were planted in December in frosty weather, have leaves to appear?” The trees turned green, however, belatedly, and on some branches the leaves did not appear. How will the lindens feel on a busy highway?

- Frozen ground planting is a common practice. In the spring, they did not immediately bloom, because they needed to adapt to new conditions. Some branches did not survive during the adaptation period. And that's okay.

Photo: TASS/Alexander Shcherbak

In nurseries, specialists prepare large-sized plants for planting: they cut, form the root system so that it is compact, do not forget the above-ground part. After planting, it is important that the trees continue to be looked after: dead or diseased branches are cut in time, fed, watered, and their health is monitored. Plants need to be sprayed from pests and diseases, to raise immunity. To preserve moisture in the root zone, gel additives can be added to the soil. In general, dendrologists now have a huge arsenal for caring for trees in urban areas so that they feel good and live long.

– Does it mean that the well-being of limes on Tverskaya and their life expectancy depend on how dendrologists look after them?

- Of course. Another thing, I often see trees in the yards and on the streets that are not properly cared for. The main mistake is that the branches are cut incorrectly, leaving a large stump. It begins to rot, fungi and bacteria penetrate here, then the core angers, and a hollow is formed. Eventually the tree breaks and falls.

“The life expectancy of poplar in urban conditions is not more than 70 years”

– Because of this, during the hurricane over Moscow on May 29, so many poplars fell down?

- Life expectancy of poplar in urban conditions is no more than 70 years. And the trees that grow in Moscow were planted more than half a century ago! Their lifespan is coming to an end. All poplars need to be removed, they are dangerous.

In courtyards, poplars that have grown higher than the roof of the seventh or ninth floor are cut in half. But this is a controversial practice: the trees are still old, the trunks are dry, so they fall in a squally wind.

Aftermath of a hurricane in May 2017. Photo: Portal of the Mayor and Government of Moscow

In general, in natural conditions, at 50-70 years old, a tree is considered young. After 100-120 years, this is already an age, especially for fast-growing trees. Trees have a shorter life in the city.

- The main array of trees, which are already 50-60-70 years old, grow in areas of five-story buildings. Surely they will be removed under the renovation program. What species of trees could be planted in the yards of new houses?

- Poplars are definitely not worth planting. I would advise planting ash. In my opinion, this tree feels good in the city, grows quickly and has a strong crown.

Gorgeous linden tree. It has decorative foliage, a beautiful silver-red crown. Of course, maple is an excellent breed for the city. Moreover, there are many species of maple, with different colors of foliage. Of the conifers, it is probably better to choose spruce or pine, but only of a small height.

I would not recommend arborvitae for planting. They don't feel good in the city. Still, this is not quite our tree, therefore, they require care, like shrubs: bird cherry, mountain ash, cherries. All shrubs need to be trimmed, and they are most often incorrectly trimmed or not trimmed at all.

Photo: Ivanko

- However, during flowering lindens are allergenic. They were even cut down in Moscow some time ago because of this. If they are planted in city blocks, will allergy sufferers suffer?

- Allergy is not my area of ​​expertise. I will only pay attention to the fact that all plants bloom. The birch is the first to bloom, shoots with earrings even before the leaves bloom. Some allergic people react to its pollen, but this does not mean that all birch trees need to be cut down.

– Sometimes in the winter the wipers pour the reagents directly onto the lawn. How does this affect mail and plants?

- Reagents are mainly potassium or sodium salts, that is, almost the same fertilizers that we use when growing other crops. In small quantities, they are useful, but in those volumes in which they are poured onto the sidewalk or the roadway, and sometimes onto the lawn, they are dangerous for trees and soil.

Most chemicals are used in winter when the trees are dormant, but they remain in the soil and cause damage to the plants. Alkalis or acids can neutralize the action of salts.

“For trees, cleaning leaves is definitely not useful”

– Do you think it is necessary to clean fallen leaves under trees?

- Cleaning leaves is definitely not useful for trees. Fallen leaves retain the necessary moisture for the tree, both harmful and beneficial insects and bacteria live under them. In autumn, the tree takes all the important nutrients from the leaves: proteins and carbohydrates, thus only cellulose remains in the fallen leaf, which is processed by bacteria, forming deciduous soil that feeds the trees.

Photo: Portal of the Mayor and Government of Moscow

Harvesting the leaves leads to the fact that the natural conditions of the tree are violated. Therefore, I am a supporter of leaving foliage. However, fallen leaves knock out the lawn and do not allow lawn grass to grow normally.

Then the way out can be like this - to create deciduous soil artificially. To do this, you need to collect, compost, and then scatter. This will benefit both the lawn and the trees. But this procedure is time-consuming, expensive, so one could simply leave the foliage around the tree for nutrition.

Rules for harvesting foliage in Moscow

– In the city center, trees are often wrapped in garlands to create a festive atmosphere. How does illumination affect trees?

- In my opinion, the illumination does not cause much damage to the tree, provided that the bulbs do not get very hot and do not burn the bark. But, as a rule, cold LEDs are now used, so there are no problems.

“Illumination does not injure a tree much”

Trees are injured by another practice - tying the tops of seedlings into a knot. It is believed that this way the barrel will not go anywhere, it will stand stronger, but this is a big mistake. Over time, this node begins to choke the tree, the so-called nodules are formed, from which it ceases to grow and develop.

- The forests of the near Moscow region are dying from the bark beetle. Even seven or ten years ago, there was no such problem with the bark beetle-typographer. Why has the bark beetle become a real scourge for the forests near Moscow?

– The typographer has always been dangerous and relevant for Moscow and the Moscow region. But earlier, forests were cultivated from the air and from the ground, so there was no problem.

Forests near Moscow affected by the bark beetle. Photo: TASS/Igor Zotin

In recent years, processing has not been carried out. The fighters for ecology raised a wave of protests, and they also reduced the staff of forestries, there are no foresters and there is simply no one to work. Hence the huge problem, the forests around Moscow are dying by hectares and they are being cut down. I do not rule out that this is even beneficial to someone, because empty plots remain, they can be easily taken out of the forest fund and something built.

There are preparations that can be used to process forests from the printer, but the problem is still different, there are settlements around these forests, and according to modern laws, the processing of such areas is prohibited.

Interviewed by Svetlana Kazantseva

ecology landscaping urban economy landscaping of the city Society

Topol. What happens to a tree when it is pruned? | Plants

Ask the townspeople how long a poplar tree lives on average. If earlier they talked about a hundred years and cited “three poplars on Plyushchikha” as an example, now the majority of townspeople say that 30, at most 50 years. And as an example, they cite poplars that grow under their windows. The trees were planted in the 70s, at 90's they had to be rejuvenated by pruning, and now the trunks of these trees are overgrown with mushrooms, the bark has fallen off, the branches have dried up.

Many trees are cut down in the city, but for some reason not old, dried up, but young, beautiful, slender ones. A tall overgrown tree seems dangerous, because it has a large windage, and if it falls, it can damage many cars. After all, cars are not in brick garages, but in the open. Garages that used to protect cars are being demolished all over the place, and car owners are worried about valuable property.

The tree has been shortened, the trunk is bare, but only a year will pass, and large shoots will appear on it. Large shiny leaves, which could previously be seen from the windows of high floors, are now close to us. And there is greenery, and there is a lot of light. Good, yes?

But what really happened?

Firstly, the city has lost its shade, and moisture no longer condenses on the soil, the earth is burned out, dust storms begin. Hot summer air is saturated with toxins, a short walk can turn into a big disaster. The old recommendation to take a walk in the fresh air before and after work becomes absurd, and people rush to jump into their car and get to the premises as soon as possible. The car is becoming a necessity, and people have to put up with the fact that more than half a million cars a year are added in Moscow alone.

Secondly, a tree deprived of its crown ceases to purify the air. The more polluting machines, the fewer cleaner trees. Diseases come to people, from allergies to cancer. Trees (poplar fluff, birch pollen) are blamed for allergies and destroyed, from which problems grow exponentially.

Thirdly, the wood that does not feed the branches dies, and the tree turns into a tube of bark. Inside is rubbish. Branches grow on a tube-tree, which are heavy in themselves, and have the very high windage that full-fledged trees can easily cope with. Trunks-tubes break at the base or are torn longitudinally by heavy branches. A tree that could show off for three centuries is eaten away from the inside by mycorrhiza of fungi in 10-20 years and can no longer live.

Someone says that it is not necessary. From these poplars one harm. They were planted only because they grow quickly and reproduce easily. These are useless and dangerous trees with down-allergen due to brittleness. They need to be replaced with normal trees.

Nothing like that! Poplar was chosen because it absorbs up to 45 kg of carbon dioxide per season, while the second most efficient tree, linden, absorbs only 16.

Poplar growing naturally, not brittle, only a few small branches fall off. I affirm this because a 200-year-old poplar grew in our yard, it was calculated by annual rings, when the alternatively gifted cut it down. In all my life, not a single broken off large branch. But if the poplar is cut, then dormant buds on the trunk awaken, and the branches that have grown from them at the place of abduction do not have a natural strong structure, but at the same time they increase a huge mass. They do break off.

Down does not cause allergies. But he is a great adsorbent. He collects other allergens and upsets them. Perfectly cleans the air. After the rain nails the down to the ground, allergy sufferers feel a relief compared to before the down. And what do they remember? That the peak of the allergic reaction coincided with the very two weeks when the fluff flew, and then everything went away. And they do not dare to assume that it was thanks to the poplars that it passed.

Poplar phytoncides purify the city air even in winter when there are no leaves. From spring to autumn, this tree is a living clinic. We do not use the healing properties of poplars because we are illiterate, but at any moment knowledgeable people can open our eyes to how many pharmaceuticals from pharmacies we brought home in vain, because a much better medicine grew under the window. And while it stands under the window, not crippled, our health is much better than it will be after the mockery of the tree, and even more so after its removal.

Poplars are pruned because they grow back. If poplars died immediately, like many other tree species, they would either not be touched, or they would be destroyed all at once, like lindens on Tverskaya. But a cropped poplar will not stand under any winds for 300 years. Pruning is the delayed destruction of the poplar. So let's look ten years ahead and imagine that the place where the tree is chopped up is empty. Got better? Not? So maybe you shouldn't mock a living being?

Standing up for a tree is difficult. Nobody understands. For one defender, there are three to five who are jubilant that there will be no fluff. Workers with saws can be very aggressive and ready to carry out orders at any cost. And we need to do something about this, otherwise we will be left without poplars, the city will turn into a poisoned desert. For starters, you need to at least hang up leaflets so that people know the truth and so that the fighters with poplars have doubts. And then learn to go out into the street with whole houses, as soon as special equipment approaches the poplars to destroy them. And telling good stories about poplars as opposed to evil stories that are professionally spawned by the media.

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