Northern Tree Crops

Non-Traditional Tree Crops for Northern Climates

This paper was presented at the Agroforestry Working Group Technical Session at the Society of American Foresters National Convention held at Portland, ME, October 28-November 1, 1995.  It highlights some of the information in a draft manual entitled New and Old Northern Tree Crops.  Some chapters of that manual will eventually be added to this section.  Photos were not included in the SAF version of this paper.

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.

 

Figure 1.  Some northern nuts that can be grown in zones 5-7 in North America.  Can you name these nuts?  Answers at the end of this paper.  Photo by Dr Lawrence MacDaniels.

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 (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 for livestock.

There 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.

 

Figure 2.  Hazel bush planting in southern Ontario, Canada.  This is part of a commercial nut growing and nursery operation owned and operated by Ernie Grimo.

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 been demonstrated.

 

Figure 3.  A good year's yield from one black walnut tree growing in Ithaca, NY.  Photo by Dr Lawrence MacDaniels.

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 tension wood.

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 absorb 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.

 

Figure 4.  Small-scale nut harvesting operation at Ernie Grimo's orchard in southern Ontario.

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 custom sawing.

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 identification enterprise.

What's Being Done to Improve Opportunities 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.

 

Figure 5.  Thomas black walnut.  This cultivar is a selection that cracks out whole quarters and halves.  Photo by Dr Lawrence MacDaniels.

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 seedling trees.

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.

 

Figure 6.  Heartnuts at a Northern Nut Growers August tour of an orchard in Michigan.

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?

Identification of nuts in Figure 1 from upper left to lower right: black walnut, shellbark hickory, heartnut, Chinese chestnut, filhazel (filbert/hazel hybrid), buartnut (butternut/heartnut hybrid), shagbark hickory.

Literature Cited

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, Box94, Chapin, IL  62628-094.

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.

Organizations

Northern Nut Growers Association , 9870 South Palmer Road, New Carlisle, OH  45344.

North American Fruit Explorers, Route 1, Box 94, Chapin, IL  62628-094.

 

Appendix A.  Tree Requirements and Nut/Fruit Yields

SPECIES

GROWING DEGREE DAYS (BASE 50o) NEEDED

MINIMUM SOIL DEPTH, OPTIMAL TEXTURE

BEARING AGE GRAFTS/ SEEDLINGS

POUNDS/ACRE AT AGE 10, 200 TREES/ACRE

$/POUND WHOLESALE (PICK YOUR OWN)

Hybrid Chestnut

2,300

24", fine sand

2-3 / 4-6

2,000-3,000

1.20-1.80

Hybrid Hazel

1,900

24", sandy loam

2-3 / 4-6

2,000-3,000

.80-1.20

Persian Walnut

2,300

30", sandy loam

2-3 / 6-8

1,500-2,000

.80-1.20

Heartnut

1,900

24", clay-sand

2-3 / 4-6

1,500-2,000

.80-1.20

Hardy Almond

2,300

30", sandy loam

2-3 / 6-8

1,500-2,000

.80-1.20

Ginkgo

1,900

24", loam

4-6 / 12-16

1,500-2,000

1.80-2.40

Korean Pine

1,900

24", fine sand

4-6 / 12-16

800-1,200

4.00-6.00

American Chestnut

1,900

24", fine sand

2-3 / 4-6

1,500-2,000

.80-1.20

Shagbark Hickory

1,900

36", sandy loam

4-6 / 12-16

800-1,200

1.80-2.40

Black Walnut

1,900

36", sandy loam

4-6 / 12-16

1,500-2,000

.80-1.20

Butternut/Buartnut

1,900

30", sandy loam

4-6 / 8-12

1,500-2,000

.80-1.20

Hardy Pecan

2,700

36", sandy loam

4-6 / 8-12

1,500-2,000

.80-1.20

Sweet Acorn Oaks

1,900

24", sandy loam

4-6 / 8-12

1,500-2,000

.20-.40

Honey Locust

2,700

30", sandy loam

4-6 / 8-12

2,000-3,000

.20-.40

Persimmon 

2,300

24", loam

2-3 / 6-8

3,000-4,000

2.00-3.00

Pawpaw

2,300

24", loam

4-6 / 8-12

2,000-3,000

2.00-3.00

Mulberry

2,300

30", loam

2-3 / 8-12

3,000-4,000

.20-.40

Apple, Pear

1,900

30", sandy loam

2-3 / 6-8

4,000-5,000

.80-1.20

Stone Fruit

1,900

30", sandy loam

2-3 / 6-8

3,000-4,000

.80-1.20

Appendix B.  Boltwood Uses, Values and Timber Yields

SPECIES

MOST COMMON USES

$/BF RETAIL

BF/ACRE/YEAR

Hybrid Chesnut

Restoration, Paneling, Door Frames, Sills

6-8

100-200

Tree Hazel

Fine Woodworking

4-6

100-200

Persian Walnut

Furniture, Gunstocks, Fine Woodworking

4-6

100-200

Heartnut

Furniture, Fine Woodworking

4-6

100-200

Korean Pine

Furniture, Panelling, Window Frames

3-5

300-400

Ginkgo

Fine Woodworking

3-5

200-300

Almond

Fine Woodworking

8-10

0-100

American Chestnut

Restoration, Paneling, Door Frames, Sills

6-8

(300-400)

Black Walnut

Furniture, Fine Woodworking

4-6

200-300

Butternut/ Buartnut

Furniture, Fine Woodworking

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, Barrels

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, Fine Woodworking

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 the owner, 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).