Chapter 3: Orchard Design and Layout

Since chestnut production is still a pioneering endever, there is not tried and true methods of chestnut tree variety/cultivar selection and orchard layout/design. When designing an orchard layout there are some "does and don'ts". Lets start with the don'ts because they are the most important before any tree is planted.

1. Don't plant chestnut trees in clay soil
2. Don't plant chestnut trees in wet spots
3. Don't plant all the same cultivars
4. Don't plant chestnut trees to close together
5. Don't plan on cultivating the soil near the chestnut trees
6. Don't plant European chestnut trees east of the Rocky Mountains
7. Don't plan on planting grass with 3 feet of any tree

Here is a short list of the does:
1. Use at least 3 different cultivars with at least 2 pollen producers
2. Plan on planting each tree on a 6-10 inch mound of sandy loam soil
3. Leave an area in the orchard for tree rehab and seedling development
4. Plan on using rows of trees
5. Purchase trees from a reliable nursery
6. Putting up fences to keep deer out
7. Protecting trees at the base from rodents
8. Plan on eating some chestnuts

The first step in orchard design is to select the chestnut variety/cultivars for the orchard. For a list of chestnut tree cultivars for the Eastern, Western and Pacific USA regions go to Sweet Chestnut Cultivars for the USA. If possible, check with nearby growers to find out which cultivars perform the best in your area. Once you have chosen the trees for your orchard, you will need to decide how tall you plan on letting the trees grow.

The height the chestnut trees are allowed to grow is dependent on the chestnut cultivar. American chestnut trees are a timber form tree and should not be pruned. Research has demonstrated that a chestnut tree will not produce chestnuts on shaded branches. A second generation grower in Ohio has determined that chestnut trees produce almost all of their chestnuts in a 15' vertical section of the tree. It does not matter if the 15 feet starts at 3 feet from the ground or 20 feet from the ground. The closer to the ground the first limbs are (6' for mature trees), the less maintenance the trees will require.

Continuing with the task of deciding what the trees in your orchard will look like, deciding what form you will maintain the trees is critical to a productive orchard. Some chestnut cultivars have a tendency to grow straight up and others like to sprawl. Chestnut trees that have the sprawling form are more prone to branches breaking under heavy nut loads. Chestnut trees like the American chestnut that are timber form will not effectively utilize the area allocated for each tree because the tree just wants to grow straight up to the sky.

Let's get to the math portion of the tree height determination. Since sunlight penetration is a direct relation to chestnut production, the goal must be to deliver as much sunlight as possible to every branch. From year to year the amount of sunlight falling onto the trees remains fairly constant with the exceptions of the weather and tree shading each other. During the growing season the days get longer until late June and then the days start to get shorter. As the days get linger the higher in the sky the sun is (solar elevation). As the days get shorter the sun will be lower in the sky. The farther north or south of the equator the lower the solar elevation will be. The two important variables here is the solar elevation and the tree spacing when trying to optimize chestnut production in your orchard design.

Half way between the equator and the North Pole you find the 45th parallel. The solar angle at 1:00 PM on the first day of each month April through October is: 4/1 = 49.74; 5/1 = 60.28; 6/1 = 67.11; 7/1 = 67.89; 8/1 = 62.63; 9/1 = 52.96; 10/1 = 41.53. By using these angles in some geometry calculations we find the closest the chestnut trees should be spaced is 21 feet based on the 15 foot nut production section of the chestnut tree. Good orchard practice is to allow 20% margin above the minimum spacing. This would add 4 feet to the minimum of 21 feet for a total spacing of 25 feet between trees. Many chestnut growers feel the minimum spacing between chestnut trees should be 30 feet. If the trees are allowed to grow without pruning, chestnut trees can require as much as 60 feet spacing between trees.

When selecting a plot of land for your chestnut orchard you will need to consider how big a plot of land you will need. Financial considerations are usually the limiting factor. If a specific production is the target converting production targets to plot size requirements can be mostly guessing. Top producing European cultivar chestnut orchards in California produce over 4000 pounds per acre. Top producing Chinese cultivar orchards produce about 1200 pounds per acre.

The next step in chestnut orchard design is to select specific cultivars. This is very important because some cultivars produce very little pollen. In many areas cultivars have to match each other so the bloom time matches the active pollen times. Precoce Migoule ripens its nuts in mid September, one of the earliest, but that does not mean it is first to bloom. The Colossal and the Maraval are matching for the bloom but nut fall is about 3 weeks apart. Chestnut cultivars that produce minimal pollen are called pollen sterile. Some cultivars that are pollen sterile are Colossal and Marrisard. One other important consideration is the quality of chestnuts produced in the orchard. The quality of a chestnut is composed of many criteria. Some of the physical characteristics are size, color, ease of pellicle removal, shape and overall look. For the palate, some of the characteristics are texture, sweetness, moisture content and overall taste. What makes this part of the selection process more difficult is that people do not agree with each other about what looks and tastes good. If nut quality is very important to you, then check with growers close to you to find out what cultivars they are growing. Then in the fall purchase a few pounds of chestnuts from them to eat for yourself and friends. This should help you find a good cultivar for your orchard. This article discusses selecting a cultivar: Chestnut Tree Perfection: The Selection of a Cultivar should be very helpfull.

It is time to finalize the tree spacing and the orchard layout so plans and budgets can be formalized. To find out hour many trees you will need to purchase us the following equation:

Square feet per acre (43560)/ tree spacing squared = trees needed at the selected spacing. This equation assumes the trees will be planted in squares. Let's put an example into action - assume your orchard will be placed near the 45th parallel and the chestnut trees will be planted on 30 foot centers:

43560/(30 x 30) = 48.4 trees per acre - rounding a little will make it a simple 50 for planning purposes

In addition to purchasing chestnut trees you will also need grass seed, fertilizer and ground preparation. Plan on fertilizing the chestnut trees in the first year. Fertilizing is being suggested because most soils have some deficiencies. The fertilizer helps correct these deficiencies and chestnut trees will do much better if the soil is in good shape before the trees are planted. Before much can happen you should get a soil test performed. The soil test should include PNK and micro nutrients. Once you have the results contact your local extension agent to review the results and to guide you with the fertilizer requirements you will need for the soil. You may want to use the term "soil amendments" when talking with an extension agent because the soil may need addition components other than just fertilizer. Here is an example of the costs for preparing a (no trees or brush) 5 acre partial for chestnut trees (2009 costs):

Soil test $50.00
Ground work - contracted tractor work $300.00/acre * 5 acres = $1500.00
Soil amendments $110.00/acre * 5 acres = $550.00
Grass Seed (Orchard grass) $3.00/pound applying 7 lbs per acre on 5 acres = $175.00
Chestnut trees - grafted (from regional nursery) $23.00 per tree at 50 trees per acre on 5 acres = $5750.00
Labor - Planting trees 10 trees per hour - 5 hrs per acre - 25 hrs for 5 acres at $15.00/hr = $375.00
Total cost of this list for 5 acres = $8775.00

If your orchard will be located in an area where the orchard will need irrigation then you will need to work out a plan to deliver the proper amount of water to the chestnut trees. Irrigation systems can be very complicated and costly, possibly costing more than getting the trees in the ground. There are many variables with the cost of putting in a watering system in an orchard. Soil type and location of the water source are two of the most important when engineering a water system. Other variable that are part of designing a water system:

1. Given the water source, what is the maximum flow rate allowed by the water permit?
2. How many trees are going to be watered at one time?
3. What is the flow rate of the sprinklers/emitters?
4. How many sprinklers/emitters will be run at one time?
5. How will you make sure the ground does not get too wet, possibly killing the chestnut trees?
6. Does the water need to be filtered or chemically modified before being applied to the orchard?




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