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Horse Chestnut Tree and Conkers: Interesting Facts and Uses

Linda Crampton is a writer and experienced science teacher with an honors degree in biology. She enjoys writing about science and nature.

Conkers and a fruit capsule dropped by a horse chestnut tree

Conkers and a fruit capsule dropped by a horse chestnut tree

A Beautiful and Interesting Tree

The horse chestnut is a beautiful ornamental tree with attractive leaves and flowers. It produces prickly fruit capsules that contain a glossy brown and nut-like seed. The seed is known as a conker and has been used in a popular children's game since at least the mid-nineteenth century. The game gets its name from the seed and is known as conkers.

The scientific name of the horse chestnut tree is Aesculus hippocastanum. Despite its common name, horse chestnut isn't closely related to true chestnut trees. It's native to Southeastern Europe but is grown in parks, landscaped areas, and gardens around the world. The conkers ripen in September and October. They aren't edible and are actually toxic in their intact form. They're safe to touch, though. An extract made from horse chestnut seeds or leaves might be beneficial for a specific health disorder, as described below.

Horse chestnut trees grow in my neighbourhood in Canada and are often deliberately planted. They are one of my favourite trees. The flowers are lovely to see in late spring and early summer, and the conkers are fun to collect in autumn.

A lovely horse chestnut tree in a park in Essex, England

A lovely horse chestnut tree in a park in Essex, England

The horse chestnut belongs to the order Sapindales and the family Sapindaceae, or the soapberry family.

Features of Horse Chestnut Trees

A horse chestnut tree may grow to over a hundred feet in height. A mature tree is densely leaved in summer and is an impressive sight. The trees are sometimes planted on either side of a road, forming beautiful avenues. They are valued for their beauty, the nectar that their flowers provide for bees, and their conkers.

The leaves develop from sticky buds and are said to be palmately compound. This term means that a leaf consists of smaller leaflets that radiate from a common base. There are five to seven leaflets in a leaf. Each leaflet has toothed edges and a pointed tip. The wood of horse chestnut is soft, light, and weak. It isn't very good for building things.

Flowers and Fruit

Horse chestnut flowers are mainly white but have attractive pink or yellow blotches at their base. The reproductive structures protrude from the flowers, as can be seen in the photo below. The flowers are born in erect spikes that are sometimes called "candles" because they look as though they are lighting up the tree.

The fruits are large and prickly. They are green at first and turn yellow in the autumn. Each fruit generally contains one conker (or horse chestnut) but may occasionally contain two or even three conkers. In the autumn the fruits fall to the ground, often already open. The seeds, or conkers, are a beautiful, rich brown colour and have a glossy appearance. A white mark is present at one end of the seed.

There are several possible reasons why Aesculus hippocastanum is known as a "horse" chestnut. When a leaf drops, the scar left on the tree is shaped like a horseshoe. The scar also contains seven marks around the edge that look like the nails of a horseshoe. Another possible reason for the name is that it was once thought (mistakenly) that horse chestnuts helped cure horses of chest complaints and made their coats shiny.

The name conker may have come from the sound that's made as two conkers hit each other. Another possibility is that it was derived from the French word "cogner", which means to "hit or knock". In some regions of Britain conkers are given alternate names, including obblyonkers and cheggies. Conkers with flat sides are sometimes called cheesers.

A horizontal view of a horse chestnut flower spike; the spikes are arranged vertically on the tree and look like candles

A horizontal view of a horse chestnut flower spike; the spikes are arranged vertically on the tree and look like candles

The Conkers Game

Conkers is a traditional game in the UK, where I grew up. The goal of the game is for a person to use his or her conker to break one belonging to another person.

The earliest games of conkers were actually performed with hazelnuts or sea shells instead of horse chestnuts. The horse chestnut tree wasn't imported into the United Kingdom until the 1600s. The first recorded game of conkers played with horse chestnut seeds took place in 1848 on the Isle of Wight.

To prepare for a game of conkers, a player has to drill a hole through one of the seeds. A screwdriver or another device is sometimes used instead of a drill. A piece of string or a shoelace is then threaded through the hole and a knot is tied at one end so that the string can't slip out of the hole.

To play the game, one person dangles their conker and the other person swings or flicks theirs at the stationary one. The players take turns swinging their conkers. A conker that breaks another one is the winner.

Competitive conkers are assigned a number. A none-er is a conker that hasn't yet broken another one while a one-er has broken one conker. However, the numbering system gets more complicated than this. A conker not only gains a point for defeating another one but also take over the points of the conker that it destroyed. For example, if a none-er breaks a two-er, the none-er becomes a three-er. It got one point for winning the game plus it gained the two points of the conker that it broke.

The World Conker Championships

In the United Kingdom, even adults play conkers. The World Conker Championships is an annual event that is held in the middle of October. The event takes place in Northamptonshire and was started by the Ashton Conker Club.

The competition organizers provide conkers for the games and don't allow players to use their own. This rule prevents players from entering the games with an unfair advantage. There are several methods of hardening a conker, which aren't allowed in the competition. These methods include soaking the seed in vinegar or salt water and baking it in an oven. Storing the seed for a year will also harden it.

Possible Medicinal Benefits of Horse Chestnut

An extract of horse chestnut seeds or leaves may have medicinal benefits. Research performed by scientists supports the idea that the extract can help chronic venous insufficiency. In this condition, a weakness in the leg veins interferes with the return of blood from the legs to the heart. The condition causes problems such as varicose veins, ankle swelling, and pain.

The NIH, or National Institutes of Health, acknowledges that horse chestnut extract has been shown to be effective for venous insufficiency. They also state that there is no evidence that it can help any other condition, however.

Any extract that's used must be free of aesculin. Aesculin (or esculin) is a toxic substance in horse chestnut. The plant also contains a substance called aescin (or escin), which is thought to produce the beneficial effects noted in experiments. Since the names of the chemicals are very similar, it’s important that they aren’t confused. A medicinal extract must be made by professionals.

Horse chestnut extract may act as a medication, but eating conkers or leaves from a tree is dangerous and should never be done. Extracts intended for medical use must be obtained from Aesculus hippocastanum and not from related plants such as Aesculus californica (California buckeye) or Aesculus glabra (Ohio buckeye). These plants haven't been tested for medicinal benefits or safety.


It's important that anyone who is considering the use of horse chestnut as a medication talks to their doctor. Natural medicines can cause side effects and interfere with the action of pharmaceutical drugs. It’s also important that extracts have a safe and effective concentration of the active chemical and that they contain no harmful substances.

The Anne Frank Tree

A horse chestnut tree was located outside the Dutch building where Anne Frank and her family hid during the second world war. Anne and her family were Jewish. During the war, German troops occupied the Netherlands. Anne often mentioned the horse chestnut tree that she saw from her hiding place in her famous diary (The Diary of a Young Girl), which was published posthumously.

Sadly, as many people may know, Anne’s family was eventually found. The capture led to her death from typhus. Though the cause of death is often said to be typhoid fever, the museum known as the Anne Frank House says that it was typhus, which is caused by a different bacterium. As its name suggests, the museum incorporates the building where the Frank family hid.

The horse chestnut tree outside the hiding place survived for fifty years after Anne’s death. Unfortunately, it was eventually affected by disease and died. Before it was completely dead, new saplings were grown from its conkers by people concerned about the tree's fate. These saplings were sent to different places around the world. They are a poignant reminder of the life and fate of Anne and her family.

The effect (of the leaf miner moth) on the appearance of horse chestnut trees in late summer can be profound.

— Royal Horticultural Society

Effects of the Leaf Miner Moth

The horse chestnut is a much-loved tree in the United Kingdom. Unfortunately, in some parts of the country it's being attacked by the leaf miner moth, or Cameraria ohridella. The moth causes the leaves of horse chestnut to turn brown and fall off the tree in late summer instead of in the fall.

The damage is done by the larvae of the moth. They "mine" their way through the leaves as they feed on leaf tissue. Although infected trees look very unattractive, they aren't killed by the moth. The damage to the leaves develops too late in the growing season to have much effect. The seeds or conkers may be smaller than normal, however.

There has been some concern that horse chestnut trees are being weakened by the moth's presence, which might make them more susceptible to microbe infections. Recent research has dispelled this notion, however. The video below discusses the potential effects of the leaf miner moth.

Bleeding Canker Disease

Scientists say that the threat of a bacterium that causes bleeding canker disease is much more serious than the threat created by the leaf miner moth. The dangerous bacterium is called Pseudomonas syringae. It creates an infection in the tree bark (a canker). The damaged area releases a sticky, reddish brown liquid. The infection may be minor. However, in severe cases the infection travels deeper into the tree trunk and kills the inner bark, the cambium (which produces new plant tissue) and the outer wood. Water and nutrient transport may be disrupted. If the infection spreads all around the tree trunk, the tree will die.

Hopefully, researchers will be able to fight bleeding canker disease and prevent the infection from spreading to new trees. The loss of horse chestnut trees from Britain would be a very sad event. They have been a beautiful part of the landscape for many years. Horse chestnut is also valued in other parts of the world, including mine. The species is always interesting to see.


This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

Questions & Answers

Question: Why are there no flowers on my horse chestnut tree?

Answer: Several factors may explain why a particular horse chestnut tree doesn’t produce flowers. First, the tree needs to be genetically capable of reproduction. Some trees may be naturally sterile. Another important factor is maturity. A tree generally needs to be several years old before it blooms. Also, the soil needs to contain essential nutrients for a tree to bloom. Fertilizer shouldn’t be added to the soil unless there is a known nutrient deficiency, however. An excessive quantity of certain minerals can be harmful.

Question: Are horse chestnuts poisonous to dogs?

Answer: Yes, they are. Dogs shouldn't be allowed to eat horse chestnuts. I've given the ASPCA (American Society for the Prevention of Cruelty to Animals) link about the potential effects below.

© 2013 Linda Crampton


Linda Crampton (author) from British Columbia, Canada on August 24, 2020:

That sounds interesting. I've heard about other people who use conkers to make laundry detergent. I think it's important to keep the conkers and the detergent out of the way of children and pets and to rinse the washed items thoroughly.

Jill on August 21, 2020:

The nuts contain saponins and if ground or chopped and soaked in water make a great laundry detergent. I have been using them all year and think they do just as good a job as purchased laundry detergents.

Linda Crampton (author) from British Columbia, Canada on August 06, 2019:

I don't know the answer with respect to your conkers, but I have noticed in my area that some fruits are ripening much earlier than they used to. This may be because summers are becoming warmer in some parts of the world.

J on August 05, 2019:

Why are the conkers shells on my tree turning brown in August? Tree has already dropped a lot of conkers.

Linda Crampton (author) from British Columbia, Canada on September 04, 2018:

Some plants have roots, leaves, or cells that prevent the entry of salt. Some absorb the salt but have mechanisms that prevent it from damaging the plant. The horse chestnut is moderately tolerant to salt, but I’ve haven’t seen any information about the specific mechanisms that it uses to deal with the substance.

tahira on September 03, 2018:

i just want to ask that how these species can grow in salty water land or sea coasts ?

Linda Crampton (author) from British Columbia, Canada on December 20, 2017:

I love the flowers, too, Peg. You're right about the fruits. I've experienced some painful experiences just trying to pick them up!

Peg Cole from North Dallas, Texas on December 20, 2017:

The flowers on this tree are incredibly beautiful. Those green horse chestnut fruits look like they could be painful if you got hit with them. I love the looks of this majestic tree.

Linda Crampton (author) from British Columbia, Canada on September 20, 2014:

Thank you very much for the comment and the vote, Alun. I think the horse chestnut is a lovely tree. It's fun to observe it and to write about it!

Greensleeves Hubs from Essex, UK on September 20, 2014:

Lovely feature about all aspects of the life of horse chestnuts. The photos are all good and helpful (I never knew that in close up the horse chestnut flowers could be so attractive) including your own, opening picture. The videos all also contribute something different.

The time lapse transformation is particularly attractive, and I love the comical conker playing video! (Personally I never liked conkers - too much risk of an errant, ill-directed conker causing a painful blow on the hand!)

Excellent introduction to a distinctive and attractive tree. Voted up, Alun

Linda Crampton (author) from British Columbia, Canada on March 26, 2014:

Thanks, ologsinquito. I think that Hildegard of Bingen was a very interesting woman. I enjoy learning about her.

ologsinquito from USA on March 26, 2014:

Great article. One of my favorite herbalists, Hildegard of Bingen, believed chestnuts could cure just about anything.

Linda Crampton (author) from British Columbia, Canada on October 24, 2013:

Thanks for the interesting comment, LastRoseofSummer2. I hadn't thought about how often conkers were mentioned in period dramas until now!

LastRoseofSummer2 from Arizona on October 24, 2013:

Thank you! I hear a lot about conkers because of all the period dramas I watch. Glad to know some more info on it all.

Linda Crampton (author) from British Columbia, Canada on October 24, 2013:

Thanks for the visit and the vote, moonlake. It's always sad when a tree is cut down. I can understand that it may need to be done when the tree is diseased or is weak and a danger to the public, but otherwise it seems like such a shame.

moonlake from America on October 24, 2013:

I love this tree but I think the only one we had in our town has been cut down. The city can be blamed for that they love cutting trees down. Voted up.

Linda Crampton (author) from British Columbia, Canada on October 22, 2013:

Thanks for commenting and for sharing your story, Deb. It's sad when a favorite tree has to be cut down.

Deb Hirt from Stillwater, OK on October 22, 2013:

When I was growing up, we had a horse chestnut in the yard, and I regularly played with the conkers, but I didn't know about the game that you played. Mostly I threw them to home in on my aim. The tree had bleeding canker, and my father eventually cut it down. Thoughts of it held many happy memories, as it was a fabulous shade tree.

Linda Crampton (author) from British Columbia, Canada on October 21, 2013:

Hi, Dianna. Yes, playing conkers is fun! Thank you for the visit and the comment.

Dianna Mendez on October 21, 2013:

We had these tress in Indiana and I failed to realize this game of conkers a child it would have been fun! Thanks for the education!

Linda Crampton (author) from British Columbia, Canada on October 17, 2013:

Hi, Nell. Thanks for the comment. I've heard about the idea that conkers repel spiders, but I haven't seen any proof one way or the other. It would be very interesting - and useful - if conkers contained a chemical that kept spiders away from an area!

Nell Rose from England on October 17, 2013:

Hi Alicia, I used to love playing conkers! and its fascinating to read that the reason why they call it the horse chestnut is because of the shape left on the tree, well I never knew that! I know there is a new theory that if you place conkers around your house then it keeps spiders away, so maybe its that chemical that does it! I read that they have made a spray for spiders from it, great read! nell

Linda Crampton (author) from British Columbia, Canada on October 16, 2013:

Hi, drbj. Thank you very much for the visit and the comment - and for the humor!

drbj and sherry from south Florida on October 16, 2013:

Who knew about the horse chestnut tree and conkers and the conkers game, Alicia? Not me. So it was extremely educational and entertaining to read your fascinating treatise on same. Thank you for this exceptional exposition. Now I'm worrying about conkers who may be susceptible to cankers.

Linda Crampton (author) from British Columbia, Canada on October 16, 2013:

Thanks, DDE. I appreciate your comment.

Devika Primić from Dubrovnik, Croatia on October 16, 2013:

The Horse Chestnut Tree and Conkers a beautifully presented hub on this topic, and I so enjoyed learning more about this tree.

Linda Crampton (author) from British Columbia, Canada on October 15, 2013:

Thanks for the visit and the comment, Pamela. Nature is an interesting topic to explore!

Pamela Oglesby from Sunny Florida on October 15, 2013:

All of this information about this tree is new to me and very interesting. I am always interested in reading about nature and you did an excellent job of presenting the information in a very interesting way. Also hub.

Linda Crampton (author) from British Columbia, Canada on October 15, 2013:

Thank you very much, CraftytotheCore! I appreciate your kind comment.

CraftytotheCore on October 15, 2013:

I love to learn about trees. Such fascinating information about one type of tree! Thank you for sharing such wisdom and knowledge.

Linda Crampton (author) from British Columbia, Canada on October 15, 2013:

Thank you for the comment, Eddy. I appreciate the vote and the share, too.

Eiddwen from Wales on October 15, 2013:

A wonderful read thus voted up plus shared.


Linda Crampton (author) from British Columbia, Canada on October 14, 2013:

Hi, Bill. It's interesting to hear about other places where conkers is played. As always, thank you very much for the comment, the vote and the shares!

Bill De Giulio from Massachusetts on October 14, 2013:

Hi Linda. Very interesting. I believe that we have Horse Chestnut Trees here in western Massachusetts. I seem to recall collecting the Conkers up near Amherst College many years ago. I also remember playing the game with the Conkers as a kid. Boy, that's a long time ago. A very interesting hub, great job. Voted up, shared, pinned, etc.

Linda Crampton (author) from British Columbia, Canada on October 14, 2013:

Thank you for the lovely comment, Faith. I appreciate your votes, the share and all your support very much. Blessings to you, too.

Faith Reaper from southern USA on October 14, 2013:

Thank you for this astounding hub here on the horse chestnut trees, for I have never heard of such and learned much from your most interesting and insightful hub here. It certainly is a stunningly beautiful tree. I loved the time-lapsed video of 8 seasons of this gorgeous tree. Thank you for the education here.

Excellent as always. Up and more and sharing.

Blessings to you,

Faith Reaper

Linda Crampton (author) from British Columbia, Canada on October 14, 2013:

Thanks, Mel. I don't think Canadians play conkers, either. It seems to be a British tradition. It's a simple activity, but it's fun. (I've had some strange experiences with the automatic spell check on my iPad, too!)

Linda Crampton (author) from British Columbia, Canada on October 14, 2013:

Thanks, Bill. I love horse chestnut trees, too!

Linda Crampton (author) from British Columbia, Canada on October 14, 2013:

Thanks for the visit and the comment, Martin.

Mel Carriere from Snowbound and down in Northern Colorado on October 14, 2013:

Fascinating story on the game of conkers, which was unknown to me until now. As far as I know us Yanks don't play it, although it sounds like fun. My iPhone doesn't know about it either, because it changed the word conkers into "con jets," which doesn't make any sense. Another drawback of these darn smart phones. Great hub!

Bill Holland from Olympia, WA on October 14, 2013:

Wow! I love the trees but knew next to nothing about them. Great information and quite interesting, Alicia. Thank you!

Martin Kloess from San Francisco on October 14, 2013:

Thank you for this.