Building the Chinese Chestnut Industry: Market Research, Cultivar Studies and Consumer Outreach at the University of Missouri Center for Agroforestry

Many people are familiar with the American Chestnut tree, once an abundant source of lumber and nut production across the southeast and eastern regions of the U.S. According to the American Chestnut Foundation, many of the dry ridgetops of the central Appalachians were so saturated with chestnut trees that in early summer, when their canopies were filled with white flowers, the mountains appeared snow-capped. In addition to harvesting the tree for lumber, rural communities stored hundreds of pounds of chestnuts for livestock feed and selling to consumers, making the nut a substantial source of economic viability. Unfortunately, in 1904, the chestnut blight (introduced from Asia) was discovered in the American Chestnut tree, and the species was eliminated from the American forest by 1950. All that remains are root sprouts and small trees that succumb to blight before they ever reach commercial size.

However, Missouri soils and climate are excellent for production of the sweet, starchy and versatile Chinese varieties of the chestnut, which can be planted in an orchard or alley cropping practice. The Chinese chestnut trees are blight-resistant, much smaller in structure than the American Chestnut and spread outward like a large fruit tree while producing a significant quantity of nuts. In addition, chestnuts provide excellent food for wildlife and can be utilized as savory feed for gourmet pork production. The nuts are low in fat and high in vitamins, and items like baking flour made from chestnuts are emerging to meet demand in the gluten-free and restricted diets market.

Establishing the Industry
The University of Missouri Center for Agroforestry (UMCA), Columbia, Mo., is working to establish a viable chestnut industry, focusing its efforts on three key areas: national market research, production techniques/ orchard management and increasing consumer demand and awareness. The long term objective is to change the image of chestnuts from that of a holiday tradition to a healthy year round food. The outcome of this effort will be an active program that reaches out to potential producers and establishes a multi-million dollar chestnut industry within the state of Missouri and surrounding states.

The Missouri Chestnut Roast, held annually in October, is part of the Center for Agroforestry’s research and outreach program to launch the chestnut industry in Missouri as a profitable crop for landowners. Fresh roasted chestnuts, grown on the Horticulture and Agroforestry Research Center farm, are a highlight of the event. This year’s Roast is Oct. 29th.

Through detailed market research and by organizing events that increase consumer awareness towards chestnuts, UMCA’s goal is to broaden market opportunities for all individuals and businesses in the chestnut marketplace. In 2004, UMCA conducted a nationwide survey of individuals and businesses active in the U.S. chestnut market (nurseries, producers and sellers). The focus of this report is to describe the market from the producers’ perspective. A Market Directory has also been published, offering contact and business information identifying more than 75 producers, sellers, nursery managers and additional entities in the chestnut industry.

At the research level, the Center’s tree improvement program focuses on identifying and testing selections of black walnut (Juglans nigra), pecan (Carya illinoensis) and chestnut (Castanea mollissima) for incorporation into agroforestry plantings. Major components of this research include (1) testing cultivars on various sites; (2) identifying superior rootstocks for grafting; (3) developing improved vegetative propagation techniques; and (4) creating a breeding program to develop improved selections. A significant component of the tree improvement research program at HARC is nut tree repositories, which serve as germplasm collections to study the adaptation and commercial potential of various cultivars of nut bearing trees to Missouri. Repositories at HARC include walnut (Juglans nigra), pecan (Carya illinoensis), Chestnut (Castanea mollissima and Castanea hybrids), and Hazelnut (Corylus hybrids).

At the consumer level, the Center hosts the annual Missouri Chestnut Roast every October at the Horticulture and Agroforestry Research Center (HARC) in New Franklin, Mo. The event is an outstanding opportunity to introduce families and landowners to the broad range of possibilities and benefits agroforestry practices can provide. Hundreds of visitors each year enjoy their first sample of sweet, Missouri-grown roasted chestnuts, along with a variety of products featuring locally-grown black walnuts and pecans, recipes and nutritional information to peak their interest in purchasing nut products. The 2005 Missouri Chestnut Roast is Oct. 29 from 10 a.m. to 4 p.m.

Center for Agroforestry post-doctoral fellow Ken Hunt explains the growing cycle of the Chinese chestnut to guests to the HARC farm. For the past nine years, the Center has conducted research to determine the best-suited cultivars for chestnut production in Missouri.

In addition to the annual Chestnut Roast, through attendance at conferences, farm tours, and chestnut roasting events throughout the year, the Center works to promote the growth potential and nutritional benefits of chestnuts to landowners and consumers at all levels. Information from the Center’s "Growing Chinese Chestnuts in Missouri" guide and "Why Chestnuts?" guide are featured in this article. For more information about the 2005 Missouri Chestnut Roast and the Center’s research initiatives on Chinese Chestnut, visit www.centerforagroforestry.org.

Growing Chinese Chestnuts in Missouri
(Excerpts from Agroforestry in Action guide. Copies may be downloaded or ordered from www.centerforagroforestry.org or the University of Missouri Extension at http://muextension.missouri.edu/explore/agguides/agroforestry/index.htm).

Chinese chestnut is an emerging new tree crop for Missouri and the Midwest. The Chinese chestnut tree is a spreading, medium-sized tree with glossy dark leaves bearing large crops of nutritious nuts. Nuts are borne inside spiny burs that split open when nuts are ripe. Each bur contains one to three shiny, dark brown nuts. Nuts are baked or boiled to help remove the leathery shell and papery seed coat to reveal a creamy colored meat. Chestnuts are a healthy, low-fat food ingredient that can be incorporated into a wide range of dishes— from soups, to poultry stuffing, to pancakes, muffins and pastries (using chestnut flour). Historically, demand for chestnuts in the United States has been highest in ethnic markets (Italian and Asian) but as Americans search for novel and healthy food products, chestnut should find wider acceptance.

Three species of chestnut provide the basis for world-wide chestnut production— Chinese chestnut (Castanea mollissima), European chestnut (C. sativa) and Japanese chestnut (C. crenata). Chinese chestnuts are a mediumsized (40 ft.) tree often multi-branched and wide spreading. With both good cold hardiness (-20 0F) and adequate tolerance to chestnut blight, Chinese chestnut is the best adapted chestnut for Missouri and surrounding states.

Site and Water Requirements
Chinese chestnut trees perform best in well-drained, loamy to sandy loam soils. Heavy poorly-drained soils or soils that perch a water table during wet seasons promote Phytophtora root rot, a devastating disease of chestnuts. Soils should be slightly acid (pH 5.5-6.5). Most Chinese chestnuts can tolerate –20 0F temperatures when fully dormant, but it is strongly recommended that frost pockets be avoided as planting sites, to avoid injury to swelling buds in the spring. Site selection similar to the requirements for peaches, where summit and shoulder slopes are chosen to allow for good air drainage, would be the safest choice to safeguard from winter and late spring frost injury.

Chinese chestnut trees are rather drought tolerant once established, but ample water throughout the growing season promotes good tree growth and regular nut production. Maximum chestnut yields and nut size are obtained only under optimum soil water conditions, therefore irrigation is recommended. A lack of water during mid-August will result in small nut size, while a lack of water in September can prevent burrs from opening normally. Micro-irrigation techniques (drip and/or micro-sprinklers) are best suited for chestnut orchards.

Selecting Cultivars
Chinese chestnut seedlings are widely available in nurseries across the Midwest. Although these trees provide adequate nut production for home use, seedlings often produce small nuts of mediocre quality. Establishing an orchard of chestnuts with seedling trees will make nut harvest overly complicated. Each tree in the orchard will ripen at a different time making quick and efficient harvest difficult. Grafted trees of proven cultivars provide more uniform ripening, higher nut quality, larger nut size, and more consistent yields. Methods for Establishing Chinese Chestnut Trees

Chinese chestnuts can be established by planting grafted trees, by planting seedling trees then field grafting one to two years later, or by planting nuts then field grafting two to three years later. Each of these methods has advantages and disadvantages. Prospective growers should choose the method most suited to their skills and economic situation.

Transplanting grafted trees of desired cultivars is the simplest way to establish an orchard. Grafted trees come into bearing two or three years following establishment depending on tree growth rate. By providing optimum weed control and ample water, you will ensure vigorous tree growth and early fruiting. Grafted trees can be purchased as bareroot or container grown trees. Bareroot trees are more widely available but suffer a greater degree of transplant shock.

Transplant shock is a major contributing factor in graft failure following establishment. Fall planting of containerized grafted trees significantly reduces transplant shock but the availability of container grown trees is severely limited. Currently, trees of all recommended cultivars are not widely available from commercial nurseries making it difficult to obtain grafted trees.

Seedling Chinese chestnut trees are widely available and are relatively inexpensive compared to grafted trees. Bare root seedling trees survive well but may grow slowly the first season. Growth is better the second growing season and in subsequent years. Desired cultivars should be grafted to seedling trees one to two years after establishment. Nut production should begin one to three years after field grafting. Starting a chestnut planting with seedlings offers the advantages of low initial costs and the opportunity to establish cultivars not readily available from commercial nurseries. Disadvantages of establishing a chestnut orchard with seedlings include delaying the onset of profits from nut production and adding the expense of grafting your own trees.

Young trees should be trained to the central leader system in order to develop a strong framework of lateral branches along the main trunk. After the trees come into bearing, begin pruning off lower limbs—one or two each year until there is enough clearance for mowing and harvesting. Once the trunk is developed, allow the tree to develop its natural spreading form. If branches with "narrow crotches" arise, prune them out. Branches with narrow crotch angles tend to form bark inclusions, which can lead to limb breakage under the weight of a heavy crop or ice storm. Mature trees require minimal pruning.

Low-Input Orchard
Chestnut plantings of 50 to 500 trees are large enough to provide landowners with a reliable source of supplemental income but are small enough to manage with hand labor. For these growers minimizing capital expenditures for machinery is the key to profitability. To maximize nut yield, initial tree spacing for the small-scale orchard should be 25 by 25 feet or roughly 70 trees per acre. As trees grow and limbs of adjacent trees start to touch, remove every other tree on the diagonal to leave trees on a 35 by 35-foot spacing. A second thinning would be necessary before chestnuts attain their final spacing of 50 by 50 feet (17 trees/ac). Thinning the orchard is crucial to providing optimal sunlight to the trees and ensure maximum nut production. Crowded trees create excessive shade on lower branches allowing flower and nut production only in the tops of the trees. Severe shading causes lower branches to die out and compromises general tree vigor

Intensively-Managed Orchard
Large nut size is the key to profitable chestnut farming. Only the largest chestnuts command premium prices. To maximize the production of premium quality nuts, chestnut trees can be grown as a high-density, intensively managed orchard crop. This level of management requires a skilled grower that is willing to plant sufficient acres of chestnuts to justify investments in trees and the mechanization of orchard operations. For additional information about management strategies, fertilization and pest control, consult the Growing Chinese Chestnuts in Missouri guide from the Center for Agroforestry.

Harvest, handling and processing
Harvest in the Midwest occurs during September and October, depending on cultivar and season. Prompt harvest of fallen nuts is necessary to prevent excessive predation by deer, possums, turkey, mice, and other wildlife. Individual trees generally drop nuts for two to four weeks. Use heavy leather gloves when handling chestnuts in the burr. The prick of a chestnut burr can be very painful. In home plantings, roll the burr under your foot until the nuts pop free before picking up chestnuts. In large plantings, mechanical pecan harvesters have worked well for harvesting chestnuts.

Chestnuts: A nutritious choice (Excerpts from the "Why Chestnuts?" nutritional guide)
Chestnuts are called the "UnNut" because nutritionally, they hardly resemble their tree-nut cousins. Unlike pecans and walnuts, chestnuts contain just a trace of fat. They are also the only nut that contains a significant amount of vitamin C. Like all plant foods, chestnuts contain no cholesterol. For weight watchers, chestnuts are a low-calorie feast. Not only are chestnuts delicious with a sweet, mild flavor, they are rich in nutritional benefits. Just a handful of other foods can match the nutritional value of a chestnut!

Chestnuts: Chock Full of Nutrition!

• High water content and very little oil makes chestnuts virtually fat free
• High fiber content makes chestnuts a filling snack
• One-third the calorie content of peanuts and cashews!
• High in complex carbohydrates for energy
• Cholesterol free
• Contain as much ascorbic acid (vitamin C) as an equal weight of lemons
• Nutritionally similar to brown rice — described as "a grain that grows on a tree"

Chestnuts Add the Gourmet Flair
There’s much more to chestnuts than roasting on an open fire! You’ll discover a whole new flair in gourmet food when you start preparing the many exciting recipes that feature the chestnut. Chestnuts can be incorporated into a wide range of dishes, from soups and poultry to appetizers, casseroles and pastries.

A puree made from cooked chestnuts is used as a filling for dessert crepes, and candied chestnuts or "marrons glace" are used in a variety of sweet desserts. Roasted chestnuts or cooked nutmeats can be easily incorporated into main dishes or salads, breads and casseroles for a unique flavor and texture.

Preparing and storing chestnuts:
Choose chestnuts in shell that are plump, shiny and a dark, rich color. Check for any sign of mold and do not purchase if present. A solid, weighty feeling with no give when pressed with your thumb means a fresh nut that hasn’t dried out. Interestingly, chestnuts are perishable and must be handled as though they were a fruit or vegetable. They must be refrigerated and will dry out if left out in a bowl with other nuts.

To prepare fresh chestnuts for using in recipes calling for chopped chestnuts, you may cut them in half with a hand pruner or culinary shears. Heat chestnuts for 5 minutes in boiling water; a hot oven (425 degrees F); or heat in a microwave for 1-2 minutes. Remove the shells while the chestnuts are still warm. The inner skin, called the pellicle, tastes bitter and should be removed. Chestnuts require 30-40 minutes cooking time, depending on desired softness. Cooked chestnuts can be pureed in a food processor.

The Center for Agroforestry has compiled an excellent collection of chestnut recipes, including methods for basic roasting and to prepare cooked nutmeats for recipes. Recipes and the "Why Chestnuts?" nutritional guide are available from the Publications link at www.centerforagroforestry.org.

Rachel McCoy
Center for Agroforestry