How To Grow A Chestnut Tree?

Chestnut trees are large, majestic trees that come in many varieties around the world. Depending on the species, the nuts may or may not be edible. They are also easy trees to grow and maintain. In this article, we’ll talk about how to grow your own chestnut tree, and how long it will take. 

How To Grow a Chestnut Tree From a Conker?

A conker is a nut that grows on a horse chestnut tree. Horse chestnuts trees, or Aesculus hippocastanum, are fast-growing trees that are native to southeast Europe and have since been introduced to parts of North America. 

Although conkers are poisonous and should not be consumed, many people collect them to grow the seeds inside. Horse chestnuts are easy to grow from seed and will tolerate many different environments. Here’s how to grow them:

Step 1: Gather Conkers

Gather the conkers that have fallen on the ground beneath horse chestnut trees. Conkers start falling from the trees and are ready to plant in September or October, depending on the climate. 

Many suggest gathering twice the number of chestnut seeds that you want to grow since only about 50% of them will end up germinating. 

Step 2: Extract the Seeds

Pull the green, spiky outer husk of the conker apart with your fingers. The seeds are the brown nuts inside of the shell. 

Step 3: Submerge the Seeds (Optional)

Many people place the seeds in a bucket full of water to determine whether they are viable. When you put them in water, the seeds that are dead and dried out on the inside should float to the surface.

The seeds that sink to the bottom should readily germinate. You can discard the other seeds by composting them or leaving them outside for animals to eat. 

Step 4: Plant the Seeds

Conker nuts need to overwinter before they germinate, meaning that they need a few months of cold weather before they are ready to sprout. The time you plant them will depend on the weather in your area. 

The seeds should be planted after the first frost so that there’s no danger of them germinating too early and dying over the winter. Plant the seeds about an inch below the surface in a pot filled with garden soil and compost. Each seed should be in its own pot.

Step 5: Care For the Seed/Seedling

Put the pot outside in a sunny location and water it when the soil starts to feel dry. You may need to place it in a frame or small enclosure to protect it from harsh weather and deer. 

Step 6: Transplant the Seedling

About one year after you plant it, the seedling should be about a foot tall and ready to transplant. To do this, dig a hole in the ground that is about as deep as the pot that the tree is in, and around 2-3 times wider. 

Remove the tree from its pot, place the root ball upright into the hole, and fill the area around the tree with dirt. Make sure the top of the root ball is level with the top of the soil. 

How To Germinate a Chestnut Tree?

American chestnut trees, although once deemed extinct, are gradually being reintroduced. The once-prolific tree succumbed to blight in the early 1900s, but scientists are working to develop disease-resistant varieties. 

The process for germinating a common American chestnut tree (Castanea dentata) is similar to that of the horse chestnut. Just like conkers, American chestnuts need 2-3 months of cold before they will germinate.

First, gather seeds that have fallen off of chestnut trees in early October and put them in a cold area until the husk splits open on its own. Once that happens, put the seeds into a plastic bag filled with damp peat moss, and poke small holes for airflow. Make sure each seed is surrounded by the moss and not touching the side of the bag or its neighboring seeds. 

Store the chestnuts in a refrigerator for at least 2-3 months, and then plant them indoors in February or March. Plant the seeds into small pots and place the container on a sunny windowsill. 

Once the danger of frost has passed, you can transplant the seedlings to the ground. For best results, harden off the young trees by gradually introducing them to the outdoors before you plant them in the ground. 

To get an idea of what the process looks like before you start, check out this YouTube video:

https://www.youtube.com/watch?v=IhA7QcTeziI

How To Start a Chestnut Tree From a Limb?

Both American chestnut and horse chestnut trees can be grown from branch cuttings. Ideally, the cutting should be taken from a younger tree. Here’s how to root them:

Step 1: Cut the Branch

Choose a healthy 6-inch section of branch and use a sharp knife to remove it from the tree.

Step 2: Scrape the Bark

Use the knife to slice a small sliver of bark from two sides of the base of the branch. This will be where new growth will come from. Dip the bottom (with the cut section) into some rooting hormone powder or gel if you have some on hand to increase your chances of success. 

Step 3: Put the Cutting in Soil

Experts recommend placing chestnut tree cuttings into a small container filled with a mixture of sand and peat moss to help it root. Once you have it in the rooting medium, place the container inside of a loosely sealed zip-top plastic bag to increase humidity. Keep the cutting moist by misting it with water as needed.

Step 4: Transplant the Cutting

Once you see holes coming from the drainage hole of the container, you can repot it into a larger container. Keep the pot in indirect light and water it at least once per week to keep it evenly moist. 

Step 5: Plant Outside

The following fall, your cutting should have strong enough roots to be planted in the ground. Place it in an area with full or partial sun and well-draining, slightly acidic soil. 

How Long Does a Chestnut Tree Take To Grow?

Like most trees that bear fruit, it takes a few years for chestnut trees to produce chestnuts. You can expect to see chestnuts from a young tree within 3-5 years of being planted. Trees that are grown in colder climates may take a little longer – more like 5-7 years, typically.  

Once a chestnut tree is around 10 years old, it can produce up to 20lbs per tree. Trees are fully mature at about 15-20 years old and can produce up to 3000 pounds of fruit per year at that point. 

Fully grown chestnut trees can get quite tall. Before its demise, the average American chestnut tree once grew to heights of 100 feet tall, with trunk diameters of at least 10 feet. Now, disease-resistant varieties that are being reintroduced can reach about 50-75 feet tall. 

Growing chestnut trees is an easy way to create shade, privacy, and a beautiful landscape on your property. As a bonus, if you’re planting American chestnuts, you’ll be helping to repopulate a species that was once very important to our forests.