CHESTNUTS
IN A NUTSHELL
Chinese Chestnut
This is not the chestnut tree of “village smithy” fame. As a matter of fact, importation of Chinese chestnut (Castanea mollissima) brought the blight which devastated the North American populations of Castanea. If your experience has been with traditional Missouri nut crops you’ll need to completely reprogram your thinking to embrace the unique nutritional characteristics of the nut as well as its harvesting and post-harvest care: all differ radically from that for other nuts. The spiny hulls make chestnuts decidedly unfriendly to foot traffic during the fall! Be certain to differentiate between planting stock: European and Japanese chestnut are less winter hardy and likely to sucumb the same blight which devastated our native American chestnuts (C. dentata, C. pumila var. pumila and C. pumila var. ozarkensis). Only the Chinese chestnut has been reliably hardy and disease resistant when planted here. The “sweet” chestnuts differ from the horse chestnut (Aescalus hippocastanum) which produces bitter nuts unsafe for human consumption.
Nuts or Wood?
Chinese chestnut is a medium sized tree (about 40’). Its wood has no commercial value at this time. As with all trees grown for nut production, branching is encouraged at whatever height is sufficient to allow access for maintenance and harvest equipment.
General Production Notes:
The best Chinese chestnut production sites have deep, well-drained, fertile soils and, like those for peaches, are on upland sites or the upper parts of slopes which facilitate cold air drainage. Plantings are generally made on 30’X30’ spacing, although additional research is needed to determine the optimal layout. Plantings can be established by direct seeding or transplanting nursery stock. Bare root stock can be used successfully for spring planting while container grown trees can be planted in both spring and fall. Grafted nursery trees are more difficult to establish, require more care for success, and grow much slower than seedling trees. The stratified seed sprouts readily and seedlings can be grafted with scionwood from known improved cultivars. Improved varieties produce large, sweet nuts. It takes less time to bring improved cultivars into production than seedlings but plan on 6-9 years from planting grafted stock to a significant harvest (750 pounds/A with 50 trees/A). Those interested in planting for family use (expect 10-15 pounds of nuts per tree nine years after planting, eventually 50-100 pounds per tree) should put out at least three different trees (use different cultivars if planting grafted stock) to assure pollination.
Once established, Chinese chestnut is relatively drought resistant but late summer dry spells can reduce nut size and/or prevent the burrs from opening properly. While yellow neck caterpillar and potato leaf hopper infestations can be problematic, the greatest pests are the small and large chestnut weevils. These can be minimized by good sanitation practices: all nuts should be gathered from the orchard floor frequently through the harvest season. Those unsuitable for sale should be burned. A hot water treatment immediately following harvest with quick cooling will kill weevil eggs before they hatch. Young trees left unprotected may be damaged when they are browsed or rubbed by deer; rabbits gnaw on the thin bark of young trees and voles will chew both tender bark and roots.
Harvest Equipment Needs:
Leather gloves are a must when handling chestnut burrs. You can roll the burrs under foot and pick up the chestnuts that pop free. Hand labor and the use of nut wizards are most economical for orchards smaller than 10 acres. Mechanical pecan harvesters can be used if available but their cost isn’t offset by the increased production until the operation reaches 50 acres. Vacuum systems offer some potential for future mechanization. Unlike pecans and black walnuts, chestnuts are high in carbohydrates and water which makes them vulnerable to molds and decay. Refrigeration immediately following harvest is required to maintain quality which deteriorates significantly after 3-4 months. Fully dried chestnuts are too hard to be consumed out of hand but can be ground into flour. Dried nuts can be reconstituted in boiling water. All dried products must be stored in sealed containers to prevent attack by stored grain pests such and the Indian meal moth.
Markets:
The University of Missouri’s Horticultural and Agroforestry Research Center (HARC) is actively exploring markets and marketing techniques for locally produced Chinese chestnuts in addition to their production studies. Their research indicates that the demand for quality chestnuts exceeds the current supply. Most chestnuts in large commercial outlets are European chestnuts, exported from Italy. Local producers generally market at on-farm operations, local farmers’ markets, and special festivals.
Fair Warning:
Chestnuts are still a novelty item in much of Missouri and the greatest challenge to producers remains marketing the crop. There are some problems with delayed graft failure and this can be particularly problematic on transplanted nursery stock. Careful attention to promoting consistent, healthy growth may minimize graft problems. Refrigerated chestnuts will eventually sprout: a raw bumper crop does not have carryover potential from year to year. There is some concern about the potential for future problems from the chestnut gall wasp, now found in several states east of the Mississippi River.
Chestnuts roasting over an open fire!!!
American Chestnuts were wiped out by the chestnut blight in the early 20th century
The Ozark Chinqapin is native to southern Missouri and it's nut is small and typically has one nut in a bur Chestnuts and Chinquapins of the Castanea genus can hybridize with each other fairly easily and create many different and interesting offspring.
Resources:
The following resources are available on line. MNGA spring and fall meetings are held at nut orchards and provide an opportunity to see various practices in action.
July 2020 Chestnut Bur