August 10, 2015
With this document we hope to provide you, a new or potential chestnut orchardist, with some guidelines and insights that might be beneficial to chestnut cultivation in midwestern states. Most of it is general information accumulated from courses, books, the internet, scientific articles, talking to those with experience and in some cases our own trial and error experiences. It should be remembered that very few of the recommendations presented here have been pursued specifically for chestnut using the scientific method, that is, one treatment versus another treatment in comparison to no treatment with several replications through time. For example, when discussing chestnut nutrition, the amount of nitrogen suggested for a five-year-old tree may be listed, but that doesn't mean the amount listed was found to be optimal for chestnut. It simply means that this amount is suggested based on other research for other tree crops and when tried it on chestnut it did not appear to hurt the trees under the circumstances listed. Another amount, slightly more or less might produce better results. It should be remembered that you are reading about a new crop for North America and the research is being conducted as you read this.
It is hoped that future guidelines will come from scientifically controlled experiments where treatments are based on comparisons. Those days might come once a chestnut industry becomes established and the industry enlists the help of scientists in various agricultural disciplines. Until then, substanital impovements in the industry will come slowly and you are left with these guidelines and your own intuition. Throughout this document, we have tried to inform you as to when we have successfully used the methods described and when you should not vary far from the suggestions.
Introduction and brief history
Over the past eight years we have attempted to help chestnut growers establish a commercial chestnut industry in Michigan and other Midwest states. In 1992, we found a fledging chestnut industry in Michigan struggling to establish and maintain young chestnut orchards based mostly on the Chinese chestnut tree. For several reasons, these early attempts were frought with failure and many growers were losing time, money, and ultimately interest. If we had to determine the one main reason why establishing a commercial industry was so difficult in those early years it might be said that the growers’ only level of knowledge was based on a few pre-established plantings located in other environs and maintained by hobbyists or people willing to accept any level of production without regard to cost or payback. This document is written for those interested in establishing commercial orchards where cost and profit are motivating factors
Among other criteria, you can "call" yourself a true commercial nut producer when you become as concerned with revenue flow as with nut production. You may "call" yourself a commercial nut orchardist if you are willing to spend $20,000 establishing an orchard that will provide you with $2,000 of annual revenue, but in reality you are really just an "orchard subsidizer." If you only spend $1,000 establishing a chestnut orchard, then you are a hobbyist. If you are ill-prepared to spend the appropriate amount of money required for good chestnut tree varieties and other important yet expensive facets of orchard establishment, then you aren’t really a commercial orchardist, either. Obviously, as with other business ventures you must be willing to spend money to make it, but you also must be frugal due the agricultural climate in which we find ourselves in today. Applying water, nitrogen, herbicides and pesticides to trees that give less than an optimum return is not only a business loss, but also a detriment to our environment.
One of the objectives of this document, as stated above, is to provide you with help for informed decision making. One of the first questions posed to me in 1992 was a simple question, “How long before the trees start producing nuts?” You didn’t need to know this information if you were a backyard or hobby orchardist, as any nuts in any time frame would be fine. However, it was one of the critical questions that needed to be answered before commercial growers should invest in chestnuts. Now in 2001, this one question still haunts me. That single question required more knowledge and information than any article, book, document, individual expert or nut-growing group could provide. By posing that one question, we knew that we understood very little about the first step in forming a commercial chestnut industry.
To answer that question we need to know the type of chestnut tree, the age of the tree when planted, how the tree was treated after planting, and how fast it would grow and mature. Even armed with that information, we would still be guessing for very few of us in Michigan have produced commercial quantities of chestnuts even though many have been trying for twenty years. My standard answer for that question is still “within 6 years.” That answer is based on my attempts to reconcile the large number of different chestnut types that have been planted and the different conditions to which they were planted. If you read through this document, you will find that I can now state explicitly that chestnut trees can produce within four years, but that is predicated on a set of specific conditions such as the variety, the pollination source, whether deer, irrigation and weed controls were applied, etc. I mention this to ensure you that there are no easy answers but as time goes on and if interest remains high, all of us will find answers together.
Michigan State University has always maintained some interest in chestnut production. Dr. Lee Taylor established a planting of chestnuts on the horticulture farm in the early 1970’s. Our laboratory started working with chestnut blight and the American chestnut tree in the early 1980’s, but, we did not become interested in cultivation and nut production until the early 1990’s. About that time, the Midwest Nut Producers Council and the Michigan Nut Growers Association established the Nut Variety Trial at Michigan State University’s Southwest Michigan Research and Extension Center (SWMREC) in Benton Harbor. While the trees planted at SWMREC were becoming established, I turned to 16, 20-years-old Chinese chestnut trees from Connecticut that Dr. Taylor had planted on the MSU Horticulture farm. We started collecting yield data on these 16 trees and after three years it was evident that each tree produced different amounts of nuts each year and at least two never produced nuts. One year, tree #1 produced the most and the next year tree #4 produced the most and tree #1 barely had a nut. The next year tree #1 and #4 produced average yields of small chestnuts and tree #16 which hadn’t produced much the previous two years, produced the most chestnuts although they were small. It became obvious that in any single year, less than half of the trees were producing any nuts at all, and these trees were over twenty-years old! Then, two of the trees looked like they were going to die as the leaves were sparse and small. We proceeded to prune, water and fertilize the trees (something that hadn’t been done for years) afterwhich they recovered and began producing small nuts again.
I bring up this case of the 16 MSU horticulture trees because I believe what I was seeing was the future of the Michigan chestnut industry if things were not changed. Those trees planted on the MSU horticulture farm in East Lansing were trees planted from nuts dropped by a mother tree called ‘Sleeping Giant’ from the Connecticut Agricultural Experiment Station in New Haven, Connecticut. This tree in Connecticut has been described as a good variety with many fine attributes. But, what we got were nuts carrying only 50 percent of the ‘Sleeping Giant’ tree and 50 percent of other trees in their orchard. Each nut would have different genetics much like the children of a family; none would be exactly like either parent tree and none of the trees in the orchard would be like any of the other trees in the orchard.
When Michigan chestnut hobbyists planted nuts to start their trees, it didn’t matter too much to them what characteristics the trees had, in fact, sometimes the more absurd the characteristics the more interesting the tree. However, a commercial industry cannot become established on seedlings. Uniformity and predictablity are requirements within an orchard. Dealing with the environment and its interactions with biological entities is hard enough without employing as many tools for predicability as possible. In the orchard, this uniformity is achieved with grafted or budded varieties. There are literally thousands of chestnut varieties found around the world but few are available in commercial numbers in this country. The chestnut variety trial at SWMREC, provided the commercial chestnut orchardist their first opportunity to observe and compare chestnut varieties growing side by side at one location in the Midwest.
These, trees established in 1992, went through the coldest Michigan winter in recent history after their second growing season and some were lost. But, those losses were the start of chestnut variety data and by 1995, we were on our way to developing guidelines based on the reactions of different chestnut varieties growing at one location in Michigan. Since then, the Northwest Horticulture Research Station near Traverse City has become the second home for a public chestnut variety trial to help growers in that location compare variety performance.
The Midwest Nut Producers Council has divided up the focus of chestnut research into three overlapping areas. The first deals with germplasm, the second deals with the horticultural aspects of growing good trees for good nut production, and the third deals with harvest, post-harvest treatment and marketing. All of these are interrelated and each feeds back information to the other. For example, if we find consumers are more interested in one type of chestnut than another, then that information would alter the germplasm aspects of chestnut production as well as marketing. If one type of chestnut stores better than another then that will alter marketing as well as germplasm aspects. The nut tree variety trials were established to study the germplasm aspects of chestnuts; experimental plots and growers' farms currently help us learn how to horticulturally manage the trees and we are now beginning to focus on post-harvest and marketing issues. Soon we will have a three-ring circus of experiments, trials and data! But right now those data is sparse.
We suggest that you join a growers’ group so that you can find people with interests similar to your own in terms of growing chestnut trees. You’ll see below that some of these groups are mainly for hobbyists and others are for commercial growers; and many growers are members of both groups. If your goals are to be a commercial grower, you cannot follow some of the recommendations that a hobby organization may suggest. If you have questions, call your county extension agent or contact Dennis Fulbright at firstname.lastname@example.org.