As many of you know, the American Chestnut Foundation has an American chestnut breeding orchard located here on our farm. Recently a new sign was put up so that you can see where the orchard is located. The orchard is located on the right side of the lane, up the hill behind where the sign is located. The American Chestnut Foundation is working to develop a blight resistant American chestnut tree by cross breeding the American chestnut with the blight resistant Chinese chestnut. The cross bred chestnut trees are then back crossed with an American chestnut a number of times until a blight resistant chestnut tree is obtained that is 15/16 American chestnut. Currently, there are about 500 trees in our orchard. The oldest trees are four years old and the youngest ones were planted this spring.
The American chestnut was at one point the most important tree in the forests from Maine to Georgia. The chestnuts provided abundant food for many species of wildlife. The wood is beautiful and is great for cabinet making and furniture. In addition, the wood is excellent for outdoor projects as well. It has the rot resistance of redwood, but it is much harder and more wear resistant. In 1904 an imported fungus caused a blight which started killing the American chestnut trees. By 1950, approximately four billion trees on some nine million acres of eastern forests had been destroyed by the blight. Only a very few American chestnut trees remain today. When the American chestnut trees died out, a lot of wildlife went with them because a lack of food. The oak tree replaced the chestnut in many areas. However, the acorn does not compare in food value to the chestnut.
This is the entrance to the chestnut orchard. Note the deer fence to keep out the deer.
When I do volunteer work, I often feel like I receive a greater blessing than the ones that I help. This has been true in our work in caring for the chestnut orchard the last three years. When we moved here, the chestnut orchard was the worst piece of ground on our farm. The Department of Natural Resources had sprayed RoundUp and killed all the vegetation before they planted the chestnut trees. As a result, instead of grass, it was the most awful plot of thistles and other weeds! The trees grew poorly. For the next two years, I would let the thistles grow until they started making a flower bud, and then I would mow the orchard. I know that some of the people from the American Chestnut Foundation thought that I didn’t mow often enough and that my plan for getting rid of the thistles wouldn’t work.
This year I received the blessing from my labor. I discovered that in taking care of the chestnut orchard I had learned an important lesson on how to take a poor plot of ground and turn it into a highly productive soil. In addition the thistles are gone! The thistle plant is at its weakest point when it is starting to produce a flower. Its energy is being put into making seed rather than into growth. By repeatedly cutting it at that stage it is weakened and eventually killed. The chestnut orchard is now the best plot of ground on our farm. It was in the chestnut orchard that we discovered how to increase the brix (sugar and mineral content) of the pasture. This summer the brix of the clover in the orchard was as high as 17%, up from only 7% last year. We are using what we learned in the chestnut orchard to improve the soil on the rest of the farm.
So how did we improve the soil in the chestnut orchard? We did it by letting the grass grow tall and then mowing it short. The roots on grass go as far down in the soil as the grass is in height above the soil. If the grass is four inches tall, then the roots are about four inches deep. If the grass is a foot tall, then the roots go about a foot deep into the soil. When the grass is cut, the roots die back to the same amount that is left above ground. By waiting until the grass was a foot or more tall before we mowed it, it meant that we were adding a lot of organic matter a foot or more deep into the soil in addition to the grass clippings that were added on top of the soil. In other words, we are creating topsoil a foot or more deep. Not only is organic matter added to the soil, but also carbon is being sequestered in the soil as the roots die back. The grass takes the carbon out of the air in the form of carbon dioxide and puts some of it in the roots.
The results in the chestnut orchard this summer were amazing to me. I noticed significant growth in the trees throughout the summer. Last year the tallest trees that were at the end of their second growing season were about 42 inches tall. Last year the American chestnut foundation said that our orchard was one of the best growing orchards in Maryland. This year, with a similar amount of rainfall, the tallest trees at the end of their second growing season were seven to seven and a half feet tall! This was accomplished without any fertilizer.
So why doesn’t this principle of soil building work on your lawn? It is because a lawn is not left to grow a foot or more tall over and over through out the summer. If a lawn is cut when it is six inches tall, it is only adding organic matter into the top six inches of soil. The deeper the top soil, the better the growth of the plants. That is one reason why raised beds tend to be more productive. They add topsoil on top of the topsoil in the soil which increases the total number of inches of topsoil for the plant to grow in.
This two year old chestnut tree is 7 1/2 feet tall. The 2×4 is 8 feet long.
This is one of the chestnut trees that was planted as a seed this spring.
You can see Sugarloaf Mountain in the background.