Northern Tree Crops
kdavies at igc.apc.org
Sat Jan 17 20:46:16 EST 1998
NON-TRADITIONAL TREE CROPS FOR NORTHERN CLIMATES
K.M. Davies, Jr.
ABSTRACT: Many tree species can produce valuable crops of food
as well as fiber. Several exotic species have been adapted to
northern climates and soils. Several domestic species hold
potential for further improvement. They are all amenable to a
wide range of management systems. Members of the Northern Nut
Growers Association and North American Fruit Explorers have over
the past 90 years substantially reduced the risks and increased
the opportunities for tree crops investments.
WHAT ARE NORTHERN TREE CROPS?
Broadly defined, tree crops are any edible fruit, nut or legume
that can serve as food for humans, livestock, or wildlife. In
the context of northern temperate climates, this means the crops
of hardy cultivars of commercial orchard tree species from
further south and west in this country and from similar climates
in other parts of the world. It also means the crops of improved
varieties of native tree species that have not yet been developed
for commercial use.
Non-traditional examples of the first category would be Chinese
chestnut, Persian walnut, European filbert/hazel, Japanese walnut
(heartnut), pecan and almond. Examples of the second category
would be black walnut, butternut, hickory, persimmon and pawpaw.
There are also hybrid trees such as Chinese/ European chestnut,
European/American hazels and butter/heartnuts.
WHAT ARE THE POTENTIAL BENEFITS OF NORTHERN TREE CROPS?
These trees will produce high quality food on marginal as well as
prime agricultural land. They can produce crops on land that is
too steep or rough for field crops 1(Smith 1950). Soils are not
exposed to erosive forces because there is no plowing or
cultivating. There is potential for integration with livestock
and row crop production systems. See Appendix A for more
information on tree crop yields and values.
Some of these trees can also produce high quality sawlogs and
turning blanks--and sequester carbon in the process. See
Appendix B for more information on boltwood values and yields.
Tree crop systems do not require the same levels of fossil fuel
inputs needed by other crop systems for plowing, cultivating and
spraying. Nut trees produce high protein foods with low levels
of saturated fat that can substitute for meat and other animal
products, thereby reducing the demand on land production systems
here is potential for high rates of return on investments,
particularly with intensive management for small scale food crop
production for direct marketing (Davies 1996). There can be a
range of management practices from intensive orchard production
to extensive wildlife and livestock systems and to extensive
systems for sawlog production. Backyard plantings can produce
delicious crops for family and friends.
WHAT ARE THE OBSTACLES TO THE DEVELOPMENT OF THESE BENEFITS?
This question may be asked in another way: Why aren't people
doing it already? The answer is that they are doing it, but on a
small scale. In the Lower Great Lakes region and in the Pacific
Northwest hundreds of acres have been planted to northern nut
trees and some new fruit trees over the past decade. In other
parts of the Midwest and Middle Atlantic regions smaller acreages
are being planted. Significant research and experimental
plantings have been made in Nebraska and Kansas. Homeowners
plant tens of thousands of non-traditional northern nut and fruit
trees every year.
These plantings are in part the result of increased availability
of high quality, low cost planting stock. The commercial
potential of grafted trees and seedlings of known cultivars has
been demonstrated by the size and quality of their nuts and
fruit. Their hardiness, precocity, and productivity have also
Thus a turning point has been reached after over 90 years of
exploring, identifying, breeding and evaluating by members of the
Northern Nut Growers Association and the North American Fruit
Explorers (Fishman 1986, Reid 1996). Other factors contributing
to this change are more sophisticated and demanding consumers who
want unusual products and are willing to pay for them, especially
if they are locally and naturally grown.
Furthermore, woodworking has grown tremendously as a hobby and
craft. Woodworkers will pay premium prices for short lengths of
nut and fruit wood. The advent of plastic tree shelters has
enhanced the survival rates and growth of young trees; tree
shelters also facilitate the production of straight butt logs.
Straight bolts of nut and fruit wood don't have the unstable
characteristics of wood from orchard trees which which have much
Nevertheless, problems remain. There is always the risk of crop
failure due to late spring frosts that kill reproductive tissues,
summer droughts that reduce the size of nuts and fruit, or
extremely cold winter temperatures that kill trees outright.
Insects and diseases are always threats. Damage by deer and mice
can be a problem, particularly in the early years of a planting
although tree shelters can minimize the risk. Squirrels are
always a problem with nut trees.
Marketing non-traditional foods can be a problem since local
markets can only absord so much production. Pick-your-own and
direct markets are limited. Competition with low cost nuts and
fruit from all over the world are a problem although northern
nuts have the advantage of better taste due to the higher oil
content. There is a paucity of good yield information for
particular cultivars under a range of growing conditions.
It takes many years to produce even a short sawlog and little is
known about growing nut and fruitwoods primarily for this
purpose. Radial saws maximize utilization of small logs, but
there are very few in commercial operation, even for small-scale
WHAT ARE THE OPPORTUNITIES AND RISKS?
For the moment there is great opportunity and great risk for
small scale plantings for food production. Opportunities for
high quality sawlog and turning blank production are perhaps less
profitable and definitely longer term than opportunities for food
production, but the returns on investment can be quite good,
especially in comparison with other small-scale tree planting
ventures (Davies 1996). If nut and fruit tree crops are planted
for aesthetic and habitat diversity, the financial opportunities
are quite low but so are the risks.
There's also some opportunity for identifying superior trees
among large numbers of seedlings of known parentage. If large
numbers of seedling trees are planted primarily for
sawlog/turning blank or wildlife food production, this part of
the enterprise can carry the much more speculative seedling
WHAT'S BEING DONE TO IMPROVE OPORTUNITIES AND REDUCE RISKS?
It's important to keep in mind that the California (Persian)
walnut that we're so familiar with is the product of thousands of
years of breeding and selection. Our native hickories and
walnuts are similar to the thick-shelled Persian walnuts of 5,000
years ago. Our persimmons and pawpaws have great potential for
improvement through breeding and selection.
Our native pecan is the only North American tree crop species
that has attained widespread commercial use. Superior wild trees
were identified and improved to develop an important industry in
many parts of the South. Our commercial cultivars of apple,
peach, pear, Persian walnut, filbert/hazel and almond were all
developed from European stock.
Although superior cultivars of native nut trees have been
identified that crack out large, whole kernels, the Northern Nut
Growers Association has only been at this work for 90 years.
Improving the quality of nut and fruit trees takes much longer
than improving the quality of annual plants because it takes much
longer for them to reach sexual maturity (Reid 1996). This
causes their breeding cycles to be much longer.
University and agri-business researchers have stayed away from
non-traditional tree crops because of the high risks and long
breeding cycles. Small private growers who don't have the
short-term time constraints of universities and corporations can
make valuable contributions.
WHAT CAN YOU DO?
You can help to fill this research gap and have fun doing it by
planting trees, keeping records on them, and reporting the
results to the Northern Nut Growers Association. The association
will take your data along with data from across North America and
other parts of the world and eventually come up with some very
solid information. You can also enjoy the fruits of your labor
in 2-3 years from grafted trees and in 4-6 years from precocious
You can learn about tree crops by attending meetings of state nut
and fruit growers associations and by attending the annual
meetings of the Northern Nut Growers Association and/or the North
American Fruit Explorers (addresses below). You can meet
experienced growers and researchers at these meetings and learn
about grafting trees, planting and maintaining them. You can
also obtain the newest and best tree stocks that are seldom
available from big commercial nurseries.
If some futurists are correct in their projections of oil
shortages in the first part of the next century, the work of tree
crop breeding will be essential to the development of
post-industrial agriculture. As oil becomes more costly, tree
crop agriculture systems will evolve to supplement and replace
annual crop systems that require greater amounts of fossil fuel
for their production. Chestnut flour may substitute for wheat
other grain flowers. Nut meals may substitute for meat.
Nut and other tree crops can produce a wide range of benefits to
people directly through food production and indirectly through
environmental conservation, carbon sequestration and fossil fuel
economies. They also offer aesthetic diversity and beauty, plus
wildlife habitat enhancement. If you're going to plant a tree,
why not plant a nut or fruit tree?
DAVIES, K. 1996 in progress. New and Old Northern Tree Crops.
To be self-published. P.O. Box 601, Northampton, MA 01061-0601.
FISHMAN, R. 1986. The Handbook for Fruit Explorers. North
American Fruit Explorers. Route 1, Box 94, Chapin, IL
REID, W., ed. 1996 in progress. Nut Tree Culture in North
America (Third Edition). Northern Nut Growers Association.
SMITH, J.R. 1950. Tree Crops: A Permanent Agriculture.
Devin-Adair. Old Greenwich, CT.
Northern Nut Growers Association, 9870 South Palmer Road, New
Carlisle, OH 45344.
North American Fruit Explorers, Route 1, Box 94, Chapin, IL
APPENDIX A. TREE REQUIREMENTS AND YIELDS
SPECIES GROWING MINIMUM BEARING AGE POUNDS/ACRE
DEGREE SOIL DEPTH, GRAFTS / AT AGE 10,
DAYS (BASE OPTIMAL SEEDLINGS 200
50o) TEXTURE TREES/ACRE OWN
Hybrid 2,300 24", fine 2-3 / 4-6 2,000-3,000
Hybrid Hazel 1,900 24", sandy 2-3 / 4-6 2,000-3,000
Persian 2,300 30", sandy 2-3 / 6-8 1,500-2,000
Heartnut 1,900 24", 2-3 / 4-6 1,500-2,000
Hardy Almond 2,300 30", sandy 2-3 / 6-8 1,500-2,000
Ginkgo 1,900 24", loam 4-6 / 12-16 1,500-2,000
Korean Pine 1,900 24", fine 4-6 / 12-16 800-1,200
American 1,900 24", fine 2-3 / 4-6 1,500-2,000
Shagbark 1,900 36", sandy 4-6 / 12-16 800-1,200
Black Walnut 1,900 36", sandy 4-6 / 12-16 1,500-2,000
Butternut/Bu 1,900 30", sandy 4-6 / 8-12 1,500-2,000
Hardy Pecan 2,700 36", sandy 4-6 / 8-12 1,500-2,000
Sweet Acorn 1,900 24", sandy 4-6 / 8-12 1,500-2,000
Honey Locust 2,700 30", sandy 4-6 / 8-12 2,000-3,000
Persimmon 2,300 24", loam 2-3 / 6-8 3,000-4,000
Pawpaw 2,300 24", loam 4-6 / 8-12 2,000-3,000
Mulberry 2,300 30", loam 2-3 / 8-12 3,000-4,000
Apple, Pear 1,900 30", sandy 2-3 / 6-8 4,000-5,000
Stone Fruit 1,900 30", sandy 2-3 / 6-8 3,000-4,000
APPENDIX B. BOLTWOOD USES, VALUES AND YIELDS
MOST COMMON USES $/BF RETAIL
Hybrid Chesnut Furniture Restoration, 6-8 100-200
Panelling, Door Frames,
Tree Hazel Fine Woodworking 4-6 100-200
Persian Walnut Furniture, Gunstocks, 4-6 100-200
Heartnut Furniture, Fine 4-6 100-200
Korean Pine Furniture, Panelling, 3-5 300-400
Ginkgo Fine Woodworking 3-5 200-300
Almond Fine Woodworking 8-10 0-100
American Chestnut Furniture Restoration, 6-8
Panelling, Door Frames,
Black Walnut Furniture, Fine 4-6 200-300
Butternut/ Furniture, Fine 3-5 200-300
Shagbark Hickory Tool Handles, Pilings 2-4 200-300
Hardy Pecan Panelling 3-5 200-300
Sweet Acorn Oak Furniture, Flooring, 3-5 200-300
Honey Locust Pallet Stock 0-1 200-300
Persimmon Golf Club Heads 8-10 200-300
Mulberry Primitive Bows 5-7 100-200
Apple Fine Woodworking 10-12 100-200
Pear Musical Instruments, 12-16 100-200
Stone Fruit Fine Woodworking 10-12 0-100
NOTES: The values shown above are for rough sawn, kiln dried
lumber. The cost of marketing is about 40% of retail. The costs
of tree felling, skidding, log bucking, trucking to mill, sawing,
drying, and sorting should be about $.30 per board foot (bf).
Therefore, to get the net (stumpage) value to theowner, use the
following formula: Stumpage value = (.6 x retail value) - $.30
per board foot. Yields are estimated averages over 50 years on
red oak site index 70 land.
SOURCE: Davies (1996).
1 A paper presented at the Agroforestry Working Group
Technical Session at the SAF National Convention held at
Portland, ME, October 28-November 1, 1995.
2 Karl M. Davies, Jr., Consulting Forester, P.O. Box 601,
Northampton, MA 01061-0601.
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