Horse Chestnut Tree Identification, Growing Tips: Bitter Nut (Healing Facts)

Woman looking at a horse chestnut tree after learning how to identify horse chestnuts, how to grow, healing bitter nut tree and how to spot horse chestnut leaves, seeds and growing zones.

Known for its glossy spherical seed, healing properties, and high toxicity, the European Horse Chestnut Tree boasts more than just showy flowers.

The combination of these contrasting traits also makes it an interesting plant to study, while also highlighting its variety of uses that extend beyond landscaping.

If you are interested in learning more about Aesculus hippocastanum,2 the following guide can give you an overview.

This guide provides information about the Horse Chestnut tree, why it’s known as the Bitter nut tree and the cool healing options of this toxic attributes, but also explains how to grow this hardwood tree for yourself.

Horse Chestnut Tree, European Horse Chestnut, Common Horse Chestnut

(Aesculus hippocastanum)

Horse Chestnut Tree in oval frame showing close up view of Horse Chestnut leaves and flowers.
  • Family: Sapindaceae
  • Genus: Aesculus
  • Leaf: Green, compound, lobed
  • Bark: Gray, ridged
  • Seed: Brown, spherical, glossy
  • Blossoms: White, yellow, red
  • Fruit: Green, spiky, leathery
  • Native Habitat: Southeastern Europe
  • Height: 50-75 feet
  • Canopy: 40-70 feet
  • Type: Deciduous
  • Native Growing Zone: Southeastern Europe

IUCN Red List of Threatened Species Ranking

Vulnerable

NE
DD
LC
NT
VU
EN
CR
EW
EX

Image Credit: Image: Alicja (_Alicja_)27

Horse Chestnut Tree Facts: Bitter Nut, Healing Properties, and Toxicity

Popularly known as the common Horse Chestnut, the European Horse Chestnut belongs to the family of plants called Sapindaceae.1 This makes it different from the American Chestnut Tree, which hails from the family Fagacea.

The contrast between these trees shows across their leaves and flowers. But most of all, it is evident in the seeds or nuts that are produced by them.4

While the American Chestnut Tree produces multiple sweet and edible nuts through the same fruit, the Horse Chestnut Tree contains typically one bitter and inedible nut per fruit.

The Horse Chestnut is also infamous for being highly poisonous.

From its bark to its flowers, nearly all of the tree’s components are toxic in their natural state and pose a danger to humans when ingested.

Eye level view of a full grown Horse Chestnut Tree growing on a grassy surface in the month of September.

(Image: AnRo000228)

This gives the Horse Chestnut Tree leaf, fruit, and even its bitter nut or seed a bad reputation that may cause you to think twice before bringing this plant home.

But that is where you need to consider that the tree only causes toxic effects when you ingest its components and does not cause poisonous effects when touched.

The Horse Chestnut Tree also holds a few perks that make it a popular choice for gardening and landscaping projects. This includes its showy and appealing flowers that grow in a cone-shaped cluster and make for a stunning sight.

Due to the overall appearance of these flowers, they look like tiny and colorful Fir trees themselves.

The Horse Chestnut Tree also displays fantastic fall colors where its brilliant green leaves turn various shades of gold and yellow in autumn.

Some ornamental hybrid varieties take this to another level to have the tree show off different colors of red and orange. This makes Horse Chestnut Trees quite the addition to a landscaping project that wants to show off the beauty of nature.

In addition to that, Horse Chestnut extract also offers a few healing properties after its toxic substance is safely removed. This can help with a variety of medical conditions such as chronic venous insufficiency (CVI).5

While anecdotal accounts claim that Horse Chestnut extract can also help with other conditions, more research is needed to prove its effects on other conditions. You should ask your physician if Horse Chestnut extract is right for you.

What Do Horse Chestnuts Look Like? Here’s How To Identify Horse Chestnut Tree

Whether you are on a mission to spot random trees or want to see a Horse Chestnut in person, it is important to know the identifying traits of the popular tree.

For what it’s worth, the Horse Chestnut tree’s attributes make it stand out of the crowd and let you discover it in gardens or in the wild with ease.

Graphic of Horse Chestnut Tree Identification showing Horse Chestnut Tree height from 50-70 feet, and Horse Chestnut Tree Identification of its leaves, flowers, seeds, and bark.

First of all, the Horse Chestnut Tree is a tall tree with 50-75 feet of height that makes it prominent among many other plants. Its oval or rounded canopy can range between 40-70 feet in width, which makes it even more distinct.

This canopy is made more dramatic with the presence of dark green, palmately compound leaves that are long and serrated across the edges. In fall, these magnificent green leaves take on gorgeous gold to yellow hues, which makes for a dramatic sight due to the sheer size of the tree.

But the Horse Chestnut Tree gets bragging rights of being different due to its flowers. Shaped in clusters and standing upright, these white flowers with yellow highlights look like little trees against the green foliage of the tree.

Apart from other trees are its upright clusters of cone-shaped flowers. You can spot these 5-12 inch flowers typically in May-June.

Each cluster has multiple flowers that are white in color, with yellow highlights gathered around a red center.

Another thing that makes the Horse Chestnut Tree different from many other trees is its spiky and leathery light-green fruit. This 1-3 inch fruit is spherical in shape and contains a spherical, brown, and glossy ball-like seed within it.2

This seed is called “bitter nut.”

But as appealing as the bitternut might look, you should never eat this highly toxic seed on its own. If you want to consume Horse Chestnut extract, you need to purchase the specialized form that has poisonous substances removed from it.

Additionally, you should only do that after consulting with your doctor.

The Horse Chestnut Tree may have likely gained its name from a natural phenomenon that occurs within the tree. When leaves fall off of a horse chestnut, they leave a lasting mark on its twig that resembles the nail patterns on a horseshoe.6

It is widely theorized that this might be the reason why Aesculus hippocastanum is now associated with horses. In contrast, another theory suggests that the tree might have earned its name due to being fed to horses in order to alleviate their cough.7

What Do Horse Chestnut Tree Leaves Look Like?

Horse Chestnut Tree leaves are palmately compound. They are lobed, serrated, and long in appearance while boasting of a showy, lustrous green color.

These leaves turn gold to yellow in the fall.2

What Does Horse Chestnut Tree Flower Look Like?

If you want to learn how to identify Horse Tree flowers, you don’t have to try too hard. These flowers grow upright in a cone shape, which also makes them look like little Fir Trees against the Horse Chestnut Tree’s foliage.

The color of these flowers ranges from white to yellow. You may also be able to spout a red center between their delicate petals.2

What Do Horse Chestnut Tree Seeds Look Like?

You can tell Horse Chestnut Tree seeds apart from others by their glossy sheen, brown color, and spherical shape. Also called Bitter nuts, they come from the green and spiky spherical fruit of the horse chestnut tree.

Typically, only one seed is derived from a single fruit.24

What’s the Difference Between European Horse Chestnut and Red Horse Chestnut?

If you are wondering what sets the European Horse Chestnut Tree apart from the Red Horse Chestnut Tree, you don’t have to dive too deep to find the answer.

First things first, the Horse Chestnut Tree is also known as Aesculus hippocastanum, while the Red Horse Chestnut is also called Aesculus x carnea.

Low angle view of Horse Chestnut Tree with yellow leaves.

Apart from their scientific names, you can also remember that both trees hold differently-colored but still breathtaking flowers. The European Horse Chestnut popularly boasts of white flowers, while the Red Horse Chestnut stays true to its name and blooms pink to red flowers.8

The different sizes of their flowers are yet another thing that you might need to note down about both trees. Red Horse Chestnut flower clusters are under 6 inches in height, which makes them smaller than the 5-12 inch tall flower clusters of the European Horse Chestnut Tree.

But you will be interested in knowing that the differences don’t end there. Red Horse Chestnut Trees are smaller than their more popular counterpart.

Where the European Horse Chestnut Tree gives you a sight of a 50-75 foot tall frame, the Red Horse Chestnut Tree reaches its maximum growth spurt at 30-40 feet. This is also true for the width of both trees.

The European Chestnut Tree has a width of 40-70 feet, but the Red Horse Chestnut Tree only reaches 25-35 feet in width.

If you want to learn the difference in the upkeep between the European Horse Chestnut Tree and the Red Horse Chestnut Tree, you might prefer the latter. It’s because the Red Horse Chestnut Tree can typically hold its own against harsher conditions.

With all the differences that they bring to the table, both of these trees remain highly poisonous for humans. This is a stark reminder for you to never ingest any components from either of these plants, no matter how strikingly beautiful they might look at first glance.

If you found this information to be super enthralling, you can continue learning about Horse Chestnut Tree identification, growing tips: Bitter Nut (healing facts), and risks of toxicity.

Horse Chestnut Tree Symbolism: What Does It Represent?

Interpreting the symbolism behind different types of trees is more of a subjective take than an objective analysis. It is because each tree, its benefits, and its drawbacks can present quite a few allegories.

Depending on who you ask, the same tree can hold wildly different interpretations for varied groups of people.

First and foremost, the Horse Chestnut Tree is associated with the game of “conkers,” which is also the alternative name given to the tree’s Bitter Nut as well as the plant itself in the United Kingdom.

Conkers is a children’s game where the fallen spiky fruits of the Horse Chestnut Tree play a major role.

To some, this makes the tree symbolize playfulness, nostalgia, and the feeling of being together with loved ones.6

Eye level view of Horse Chestnut Tree Barks.
But when you look at the Horse Chestnut Tree from another lens, you can associate how it was used in the writings of Anne Frank. This can point out that the tree symbolizes hope through its existence as well as its beauty.6

In other interpretations, Horse Chestnut Tree symbolism may outline health, potency, and resilience due to the health benefits that it brings to the table.

With that, the process of removing toxins from Horse Chestnut extract to make it useful instead of harmful to humans can also stand out as a symbol that highlights the value of hard work, purification, perseverance, and self-improvement.

Planting Tips for Horse Chestnut Tree (Aesculus hippocastanum)

The Horse Chestnut Tree is pretty easy to grow and does not require you to move mountains in order to thrive.

But in order to know exactly what to do and avoid unnecessary issues, it is still important for you to learn a few key points before you start growing your very own European Horse Chestnut.

The following sections guide you through crucial aspects of successfully growing and caring for your Horse Chestnut Tree.

Horse Chestnut Tree Growing Zone

The U.S. Department of Agriculture (USDA) determines suitable environments for plant growth by assessing the annual average minimum winter temperature of different areas.

These findings are then integrated in the USDA Plant Hardiness Zone Map,9 which allows you to easily discover if specific plants can thrive in your area.

According to these findings by the USDA, the Horse Chestnut Tree is best grown in USDA Plant Hardiness Zones 4-7.2 If your location falls under these zones, you can be confident in your plans to grow a European Horse Chestnut.

When To Plant Horse Chestnut Tree for the Best Yield

Horse Chestnut Trees are ideally planted in fall. Before you plant them in the ground, you need to germinate your Horse Chestnut Tree seeds by putting them in a pot.10

When you transplant a Horse Chestnut Tree by following this method, it increases your chances for success.

After the winter has passed, your Horse Chestnut becomes ready to start its growth from the following spring. Once seedlings become saplings in a few months, you can transplant them into the ground.

You may do so in spring or autumn.

Best Growing Conditions for Horse Chestnut Tree

The best-growing conditions for Horse Chestnut Tree include:

  • USDA Hardiness Zones 4-72
  • Moist but well-drained soil
  • Loamy soil
  • Full sun (at least 4 hours a day)/partial shade11
  • 4.5-6.5 soil pH3

Watering Needs for Horse Chestnut Tree Plants

The Horse Chestnut Tree thrives in moist soil, which requires you to prevent its soil from getting dry. After planting new Horse Chestnut Tree plants, you might need to water them once a week during the summer to achieve ideal soil conditions.3

If your Horse Chestnut Trees are mature, you will not need to water them every week. Instead, you will just have to make sure that their surrounding soil is moist.

Horse Chestnut Tree Growth Rate: How Long It Takes To Grow Horse Chestnut Tree

A Horse Chestnut Tree can grow between 1-2 feet every year.11

Besides this neat piece of information, you may also want to remember that only younger Horse Chestnut Trees have a fast growth spurt.

Graphic showing Horse Chestnut Tree Growth Rate showing from year 1 sapling stage, year 2-5 juvenile tree, year 6-10 young adult tree, year 11-30 mature tree, and year 50 beyond fully mature tree.

(Fully Mature Tree Image: AnRo000229)

The older your Horse Chestnut Tree is, the slower it will grow every year.12

How Far Apart To Plant Horse Chestnut Tree

When you are planting trees next to each other, you need to be super considerate about their height, width, and frame.

The Horse Chestnut Tree is a large tree, which means that you need to put a distance of 20-30 feet when planting these trees next to each other.13

How Much Sunlight Does Horse Chestnut Tree Need Each Day?

Horse Chestnut prefers full sun and partial shade,11 which means that it requires at least 4 hours of direct sunlight.

Full sun is especially important for younger plants that need the sun’s nourishment in order and thrive and grow to their full size.

How To Stop Horse Chestnut Tree Disease: Prevention and Precautions

Horse Chestnut Tree can hold its own when it comes to most diseases that affect many other trees.

But it is still susceptible to the following conditions.

Leaf Blotch

Guignardia Leaf Blotch is so common for Horse Chestnut Trees that when you remotely mention horse chestnut disease, many people immediately assume that you are referring to Leaf Blotch. This fungal disease affects Horse Chestnut leaves and causes them to appear scorched with orange and brown spots.

These spots may first appear as light-green lesions that may later take on orange and brown hues. After reaching a certain size, the disease stops spreading on its own, only to rear its head later.

It also leaves burnt-looking foliage in its wake that mars the beauty of your otherwise stunning Horse Chestnut Tree.

Guignardia Leaf Blotch affects virtually every Horse Chestnut Tree. But it does not affect the tree’s health or growth.

With that being said, you can still take actions such as getting rid of affected leaves, pruning branches to prevent excess dampness and use of fungicides in extreme cases.14

Powdery Mildew

Powdery Mildew is exactly what it sounds like, a formation of white fungus that resembles a coat of powder. This disease usually attacks leaves and causes them to curl in on the infected side, but it can also expand to buds and stems and make them appear like they have baby powder on them.

Apart from causing aesthetic issues, Powdery Mildew can also cause leaves to fall. This can affect the look of your Horse Chestnut Tree foliage.

The disease thrives under humidity, which means that it is not apparent in seasons with a moderate to high amount of rain.

With that being said, powdery mildew does not affect the overall health of your Horse Chestnut Tree. But if you want to steer clear of its path, you can take certain actions to prevent the spread of Powdery Mildew.15

This includes maintaining a proper amount of space within trees when planting them and refraining from the use of fertilizers during an active infection.

Common Pests of the Horse Chestnut Tree

Horse Chestnut Tree can attract a few pests that include:16

Japanese Beetles

These brown-black Beetles bring harm to your tree by feeding on it in large quantities and destroying foliage in the process. You can manage these pests by physically removing them in case of low infestations and using insecticides for larger infestations.17

Bagworms

These are Caterpillars that make dangling silk bags on the tree and harm the tree by feeding on it. You can address this problem by removing silk bags as soon as they are formed and using certain pesticides during an active infestation.18

Cottony Maple Scales

These scales are known for making cotton-like egg sacs, while also secreting sticky liquid all over the tree. You can manage these scales by turning to certain insecticides and treatments.19

Oystershell Scales

These scales get their name from their Oyster-like shell. These scales are harmful enough to eliminate branches from trees.

You can resolve this issue by using a systemic insecticide or other effective solution.20

You may also look into different options for natural pest control for Horse Chestnut Tree.

While these remedies are used by select gardeners and professionals to varying results, you may still give them a trial run to see if they work for your plants.

Companion Plants for Growing Horse Chestnut Tree

When you are about to choose companion plants for any tree, you may have your work cut out for you. Horse Chestnut Trees are no different.

Close up view of Horse Chestnut Tree fruits cracked open makes the seed visible.

(Image: AnRo000230)

Some of the plants that you can comfortably pair with Horse Chestnut Trees include Barrenwort, Eastern Sowbread, and Ivy-leaved Cyclamen.21

How To Start Growing a Horse Chestnut Tree From a Seed

If you want to grow a Horse Chestnut Tree from one of its glossy seeds, you are in for a long process. But it is still not impossible for you to pull it off.

You can start with this journey in the fall by putting loamy soil in a well-drained pot, and follow that up with putting your Horse Chestnut Tree seeds into the pot. You will then need to treat these planted seeds to at least 4 hours of full sun.

If everything goes well, you may see these seeds sprout in the following spring. But this isn’t the end of your caring journey.

Instead, it is just the start. You will need to keep watering these seeds every few days and give them full sunlight for at least 4 hours.

It might take a few months to a full year before you see these seeds turn into saplings. But once that happens, you can transplant them to the ground that you have chosen as their permanent home.22

How To Start Growing a Horse Chestnut Tree From a Cutting

Growing a tree from a cutting instead of a seed requires you to put in some additional effort. This calls for you to be attentive to factors such as the time of year, the state of the cutting, and the tools you are using to plant it.

  • Time of Year: You need to plant your cutting in the fall
  • State of the Cutting: You need to get it from a young plant
  • Tools for Planting: You need to use a hormone mix to dip the cutting in before planting

After you plant your cutting, you need to remember a handful of points.

  • Store your cutting at colder temperatures
  • Wait for it to sprout
  • Plant it into the ground once it turns into a seedling23

How To Start Growing a Horse Chestnut Tree From a Seedling

Simply get your Horse Chestnut Tree seedling from a gardening store, plant it in loamy soil, and make sure that it remains moist. You also need to be thoughtful about the tree’s need for sun and give it a mix of full sunlight and partial shade.

If you take care of these requirements, you can rest assured that your seedling will grow throughout the next few months.

Eye level view of Red Horse Chestnut Tree leaves and flowers.

(Image: Hans31)

By speeding through this information, you can get a fair idea about Horse Chestnut Tree identification, growing tips, Bitter Nut (healing facts), and risks of toxicity. From there, it becomes easy for you to make the Horse Chestnut Tree a part of your home.

Do Trees Have Genders?

Do trees have genders? Trees do have genders. The gender of a tree mainly affects the appearance of its flowers and its ability to bear fruit.

However, the flowers of many trees have both male and female parts. You can learn about the different parts of a tree to get more information about this interesting natural process.

The Horse Chestnut Tree Is Not Toxic By Touch, Which Makes It a Safe and Beautiful Addition to Your Garden

If you have been skeptical about planting the Horse Chestnut Tree in your garden due to its infamous toxicity, you are not alone.

But after you learn that the tree is only toxic upon ingestion and not by touch, you can rest assured that it will not harm you or your loved ones just by being a part of your garden.

Enjoying the benefits of the Horse Chestnut tree and it’s bitter nut qualities is easy, as long as you take the right precautions.

Frequently Asked Questions About Horse Chestnut Tree

Horse Chestnut Tree Effect on Climate: How Much Carbon Does Horse Chestnut Tree Sequester?

The Horse Chestnut Tree can sequester approximately 0.53 metric tons of carbon per year.25

What Is a Horse Chestnut?

A Horse Chestnut is a type of tree from the genus Aesculus and family Sapindaceae. But the term “Horse Chestnut” may also refer to a growth in the foreleg of a horse.26

Is Horse Chestnut Tree Leaf Poisonous?

Similar to other parts of the Horse Chestnut Tree, the Horse Chestnut Tree leaf is highly poisonous if ingested by humans. If you want to experience medicinal horse chestnut benefits, you need to obtain specially-crafted extracts that have these toxins removed from them.

Growing Zones for Horse Chestnut Tree (Where To Grow): What Is the Best Growing Zone Where To Grow Aesculus hippocastanum?

You can grow the Horse Chestnut Tree within USDA Hardiness Zones 4-7.


References

1Allen, D. J., & Khela, S. (2017, July 20). Horse Chestnut. RedList. Retrieved June 22, 2023, from <https://www.iucnredlist.org/species/202914/122961065>

2North Carolina State University. (2023). Aesculus hippocastanum (Common Horsechestnut, Common horse chestnut, European Horsechestnut, Horsechestnut) | North Carolina Extension Gardener Plant Toolbox. North Carolina Extension Gardener Plant Toolbox. Retrieved June 22, 2023, from <https://plants.ces.ncsu.edu/plants/aesculus-hippocastanum/>

3Lesser, J., & Elmwood, N. (2021, September 8). Horse Chestnut Tree: Care and Growing Guide. The Spruce. Retrieved June 22, 2023, from <https://www.thespruce.com/horse-chestnut-tree-profile-5072901>

4The American Chestnut Foundation. (2015, April). TACF Fact Sheet – American Chestnut vs. Horse Chestnut. The American Chestnut Foundation. Retrieved June 22, 2023, from <https://www.acf.org/wp-content/uploads/2016/09/American-v-Horse-1.pdf>

5National Institutes of Health. (2020, October). Horse Chestnut | NCCIH. National Center for Complementary and Integrative Health. Retrieved June 22, 2023, from <https://www.nccih.nih.gov/health/horse-chestnut>

6BBC. (2017, August 21). BBC Radio 3 – The Essay, The Meaning of Trees, Horse Chestnut. BBC. Retrieved June 22, 2023, from <https://www.bbc.co.uk/programmes/b05vh43c>

7Woodland Trust. (2023). Horse Chestnut (Aesculus hippocastanum). Woodland Trust. Retrieved June 22, 2023, from <https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/horse-chestnut/>

8Bracewell, R. (2005). Aesculus × carnea red horse-chestnut. Trees of Stanford. Retrieved June 22, 2023, from <https://trees.stanford.edu/ENCYC/AEScar.htm>

9United States Department of Agriculture. (2012). USDA Plant Hardiness Zones. USDA Forest Service. Retrieved June 22, 2023, from <https://www.fs.usda.gov/wildflowers/Native_Plant_Materials/Native_Gardening/hardinesszones.shtml>

10Nature & Garden. (2023). Horse chestnut tree – planting, growing, care, and what to do with conkers. Nature & Garden. Retrieved June 22, 2023, from <https://www.nature-and-garden.com/gardening/horse-chestnut-tree.html>

11Arbor Day Foundation. (2023). Horsechestnut Tree on the Tree Guide at arborday.org. Arbor Day Foundation. Retrieved June 22, 2023, from <https://www.arborday.org/trees/treeguide/TreeDetail.cfm?ItemID=1103>

12Gilman, E. F., & Watson, D. G. (1983, November). Aesculus hippocastanum Horsechestnut. Environmental Horticulture. Retrieved June 22, 2023, from <https://hort.ifas.ufl.edu/database/documents/pdf/tree_fact_sheets/aeshipa.pdf>

13Nardozzi, C. (2023). How to Grow: Horse Chestnut – Growing and Caring for Horse Chestnuts. Charlie Nardozzi. Retrieved June 22, 2023, from <https://www.gardeningwithcharlie.com/grow-care-for-horse-chestnut/>

14University of Massachusetts Amherst. (2023). Landscape: Guignardia Leaf Blotch | Center for Agriculture, Food, and the Environment at UMass Amherst. UMass Extension. Retrieved June 22, 2023, from <https://ag.umass.edu/landscape/fact-sheets/guignardia-leaf-blotch>

15Koetter, R., & Grabowski, M. (2018). Powdery mildew on trees and shrubs | UMN Extension. University of Minnesota Extension. Retrieved June 22, 2023, from <https://extension.umn.edu/plant-diseases/powdery-mildew-trees-and-shrubs>

16Townsend, L., Larson, J., & Dillon, P. (2020, February 20). Common Insect Pests of Horse Chestnut. University of Kentucky. Retrieved June 22, 2023, from <https://www.uky.edu/Ag/Entomology/treepestguide/horsechestnut.html>

17United States Department of Agriculture. (2015, August). Managing the Japanese Beetle: A Homeowner’s Handbook. USDA APHIS. Retrieved June 22, 2023, from <https://www.aphis.usda.gov/plant_health/plant_pest_info/jb/downloads/JBhandbook.pdf>

18Shetlar, D. J. (2011, October 5). Bagworm and Its Control | Ohioline. Ohioline. Retrieved June 22, 2023, from <https://ohioline.osu.edu/factsheet/HYG-2149-10>

19Utah State University Extension Utah Pests. (2023). Cottony Maple Scale | USU. USU Extension. Retrieved June 22, 2023, from <https://extension.usu.edu/pests/ipm/ornamental-pest-guide/arthopods/scales/cottony-maple-scale>

20United States Department of Agriculture. (2011). Oystershell Scale. USDA Forest Service. Retrieved June 22, 2023, from <https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5343821.pdf>

21Morton Hall Gardens. (2023). Creating a Garden under an ancient Horse Chestnut. Morton Hall Gardens. Retrieved June 22, 2023, from <https://mortonhallgardens.co.uk/head-gardeners-journal/creating-a-garden-under-an-ancient-horse-chestnut>

22The Fair Earth Foundation. (2023). How to Plant a Horse Chestnut (Conker) Tree. Fair Earth Foundation. Retrieved June 22, 2023, from <https://www.fairearthfoundation.org/uploads/1/0/1/0/101068910/how_to_plant_a_horse_chestnut__conker__tree.pdf>

23Badgett, B., & Stanescu, A. (2023, January 21). Growing Horse Chestnut Cuttings: How To Take Horse Chestnut Cuttings And Root Them. Gardening Know How. Retrieved June 22, 2023, from <https://www.gardeningknowhow.com/ornamental/trees/horse-chestnut/rooting-horse-chestnut-cuttings.htm>

24University of Wisconsin Green Bay. (2023). Trees of Wisconsin: Aesculus hippocastanum, horse chestnut. UW-Green Bay. Retrieved June 22, 2023, from <https://www.uwgb.edu/biodiversity-old/herbarium/trees/aeship01.htm>

25Watson, J. (2017, February). Exeter University Report DraftV7. Treeconomics. Retrieved June 22, 2023, from <https://www.treeconomics.co.uk/wp-content/uploads/2018/08/Exeter-University-Report-.pdf>

26Wikipedia. (2023, April 6). Chestnut (horse anatomy). Wikipedia. Retrieved June 22, 2023, from <https://en.wikipedia.org/wiki/Chestnut_(horse_anatomy)>

27Horse chestnut, Flowering, Flower chestnut Photo by Alicja (_Alicja_). (2018, May 3) / Pixabay Content License. Cropped and added text, shape, and background elements. Pixabay. Retrieved July 10, 2023, from <https://pixabay.com/photos/horse-chestnut-flowering-3374068/>

2820130921Aesculus hippocastanum2 Photo by AnRo0002. (2014, June 29) / CC0 1.0 DEED | CC0 1.0 Universal. Resized. Wikimedia Commons. Retrieved January 17, 2024, from <https://commons.wikimedia.org/wiki/File:20130921Aesculus_hippocastanum2.jpg>

2920140425Aesculus hippocastanum2 Photo by AnRo0002. (2014, April 25) / CC0 1.0 DEED | CC0 1.0 Universal. Cropped and added image, text, shape, and background elements. Wikimedia Commons. Retrieved July 10, 2023, from <https://commons.wikimedia.org/wiki/File:20140425Aesculus_hippocastanum2.jpg>

3020180917Aesculus hippocastanum2 Photo by AnRo0002. (2018, October 7) / CC0 1.0 DEED | CC0 1.0 Universal. Resized. Wikimedia Commons. Retrieved July 10, 2023, from <https://commons.wikimedia.org/wiki/File:20180917Aesculus_hippocastanum2.jpg>

31Red horse chestnut, Chestnut tree, Tree Photo by Hans. (2013, June 12) / Pixabay Content License. Resized. Pixabay. Retrieved July 10, 2023, from <https://pixabay.com/photos/red-horse-chestnut-chestnut-tree-116746/>