Most chestnut trees are relatively easy to grow and maintain. As long as their basic needs are met, they will produce healthy growth. Whether you plan to use your tree for backyard shade, its delicious nuts, or both, it will be a rewarding experience. This article will tell you how to grow and take care of a healthy chestnut tree.
What You'll Learn Today
How Old Can a Chestnut Tree Get?
As long as they are healthy, chestnut trees are large, hardy trees that stick around for a long time. Here’s how old some of the most popular varieties can get:
American Chestnut (Castanea dentata)
The age of the average American chestnut is a loaded question without a simple answer. This tree once dominated the forests of the United States for 40 million years, up until the 1900s.
In the early 1900s, a blight fungus eradicated most of the American chestnut population. While the disease left the roots of trees able to send up sprouts, new growth is doomed to die back to the ground fairly quickly.
Back in its heyday, the American chestnut had a lifespan of about 500 years, and today, a true American chestnut only lives for about five years. Despite this, they are reasonably easy and fun to grow for that short amount of time.
Scientists, particularly those involved with The American Chestnut Foundation, are breeding blight-resistant types with American chestnuts to restore the population. Some of their blight-resistant varieties are expected to have a lifespan of about 50.
To learn more about the American chestnut tree and its revival, watch this powerful Ted Talk:
Horse Chestnut (Aesculus hippocastanum)
The horse chestnut tree is a huge variety found in several parts of Europe and North America. This variety can grow to be as tall as 130 feet and has a lifespan of about 300 years – although there are exceptions.
The oldest and largest living tree in the world, currently, is a horse chestnut tree. This tree, known as the Hundred Horse Chestnut, is located in Italy.
Despite being burnt several times by a neighboring volcano (Mt. Etna), it’s still going strong. Botanists think that the tree may be as old as 4000 years.
Chinese Chestnut (Castanea mollissima)
This is one of the smaller varieties of chestnut that exist today. Chinese chestnut trees grow quickly, but they only live for about 50 years and reach a height of around 60 feet.
How Do You Keep Chestnut Trees Healthy?
Mature chestnut trees are easy to care for and have very few needs. Once they’re established, they will essentially take care of themselves. The key to having a healthy chestnut tree is for them to get a good start in life. Here’s how:
Growing From Seed
You can collect chestnut seeds from the ground under a tree anywhere from mid-September through November. Only pick up seeds that have already fallen from the tree and are splitting open, since the rest are not ripe yet.
Once you collect your seeds in the fall, put them in the fridge until early spring. In about mid-March, you can plant them in the ground.
When you plant your seeds, set them about 3-6 inches deep into the soil. If you live in an area with deer and other critters, it’s a good idea to set up a cage around the young tree to protect it.
Once it’s in the ground, chestnut trees don’t need much except for water. Although they are drought-tolerant adults, they will need regular watering to help them get established.
Pruning
Once they are tall enough, pruning can help to keep your chestnut trees healthy and attain the shape you want. If you plan on growing an orchard and selling nuts, this is a necessary step.
For optimal production, experts recommend trimming stems that are greater than ½ the size of the main stem as it grows. These larger secondary branches can take over the main stem, taking valuable water from the top of the tree.
You can also prune any dead branches off as you notice them. With regular pruning when the tree is young, it will be trained to grow in the shape you desire.
What Causes Brown Spots On Chestnut Tree Leaves?
Brown spots on tree leaves are a common issue with horse chestnut trees, particularly in years with wet springs. The brown spots are an indication of a disease called leaf blotch, a product of a fungus called Guignardia aesculi.
You can tell if your horse chestnut has leaf blotch by the discolored areas that occur on water-soaked areas of the leaves. The brown spots sometimes have yellow borders. The affected leaves will often fall from the tree.
Unfortunately, there is no cure for this disease, but you can prevent it from spreading to other trees. To do this, rake all of the infected leaves and destroy them when they fall. This should prevent the disease from overwintering in the area.
Another tactic is to prune or thin out the branches to ensure that the leaves can dry out more efficiently after it rains. You can also try applying a fungicide in the spring to protect young leaves that are still developing.
How Do You Know When a Chestnut Tree is Dying?
There are several ways to tell if your chestnut tree is not doing well. Leaves, bark, and roots are all examples of how trees convey their health.
It’s important to keep an eye on your chestnut tree since some diseases can be treated, while others are irreparable. Here are some of the main culprits of chestnut disease:
Leaf disease
There are many kinds of fungal diseases that attack the leaves of chestnut trees. Leaf spot and leaf blotch disease are both apparent through spots on the leaves and early leaf drop. Although this likely won’t kill the tree, the fungus can travel to other trees in the area unless preventative measures are taken.
Phytophthora Root Rot
This is a severe chestnut illness that happens as a result of excess moisture. The first signs of disease show up through leaves that dry up and turn dull yellow or green.
You will also notice dark sections of bark around the upper roots of the tree, and sometimes sap that oozes from the area. Younger trees with smaller root systems are most susceptible.
Blight
This is the disease that decimated the American chestnut population a century ago. The first sign of the disease is large cankers on its branches. Next, orange or yellow spores spread amongst the limbs and enter the tree via wounds or creases in the bark.
Once the branches are infected, the leaves begin to die. The disease spreads to other chestnut trees through insects, wind, and rain.
Many people assume that huge trees are self-sufficient and are simply permanent fixtures on a property. But it’s important to protect these sometimes vulnerable giants from diseases that they cannot protect themselves from.
As long as we don’t take their health for granted, they will remain a permanent presence.
It surprises me a lot to know that chestnut trees can grow up to 500 years. Completely mind-blowing!