SONG News Spring 1996 no. 48

The Grimo Nut Nursery Production Summary

The Sweet Chestnut
The American chestnut, native to Eastern North America, was the dominate species in the Appellations. In Ontario, this includes much of South-western Ontario and the Niagara Peninsula. The tree which often grew to one hundred feet or more in height was highly valued for its timber. The rot resistant wood was used for everything from posts to barn siding and house trim.

In the early part of this century, the chestnut blight fungus was introduced from the Orient. The American chestnut which was highly susceptible to the blight was literally wiped out as a forest tree by the late 30's. Efforts in breeding and genetic engineering are in progress that would reintroduce this fine species to its native regions within the next decade. Woodlot owners will again be able to grow this fine timber tree.

Chestnut orcharding suffered the same fate as forestry. Chestnut production dropped to near zero. Introduced species from China and Japan, with blight resistance, often were poor growers or lacked hardiness. Slowly through breeding, complex hybrids began to emerge that showed some promise. Layeroka, a selection from the Okanogan Valley appeared to have many desirable characteristics. Robert Fleming at HRIO Vineland first recognized its potential. This encouraged me to use it as a breeding parent in my crosses over the last twenty or more years. I now have more than a dozen selections on trial that compete favorably with the best of the imports.

The major criteria used for making selections includes; large nut size (including size consistency from year to year), reliable productiveness, flavour, earliness of ripening, ease of harvest, blight resistance, etc. Over the years I have kept crop records on all of my orchard trees. The trees that do not measure up are removed and replaced by new crosses and selections. Some good selections are represented in the following histogram. Production is based on the crop weight divided by the tree canopy area.

Production of Selected Chestnut Trees x100 lb/acre

48|                                                Q
45|                                                Q
42| Q                         T                    Q
39| Q                         T        Q     Q     Q X
36| Q                      Q  T   L    Q X   Q     Q X
33| QL                     Q  T  QL T  Q X   Q     Q X
30| QL                     QL T  QL T  Q X   Q     Q X  
27| QL                     QL T  QL T  Q X   QL    QLXT  Q  
24| QL               QL    QLXT  QL T  Q X   QL    QLXTV Q  
21| QLX        QLX   QL    QLXT  QL T  Q X   QL T  QLXTV Q X     
18| QLX        QLX   QL    QLXT  QL T  Q X   QL T  QLXTV Q X V   
15| QLX  Q     QLX   QL    QLXT  QL T  Q X   QLXT  QLXTV Q XTV    
   1986  1987  1988  1989  1990  1991  1992  1993  1994  1995
Q = Grimo 142Q, L = Layeroka, X = Grimo 112X, T = Grimo 116T, V = 128V
Production of Selected Chestnut Cultivars
10 Year
% Large Nuts
142QLayeroka x open1978329285
Layeroka (graft)1980230965
128VLayeroka x open197981490

Though all the trees tend towards alternate bearing, trees like Grimo 142Q have annual crops of commercial quantity and quality. Grimo 142Q and Layeroka are consistently high bearing, but are pollen sterile and so at least two pollinator selections are needed to produce adequate pollination in the orchard. Grimo 112X, 116T, and 128V are maintained for this purpose. Nut size is also important. Nuts larger than 22mm (7/8") across demand a 50% higher return in the marketplace.

The Heartnut
The Heartnut, a selection of the Japanese walnut and a close relative of the native butternut, is well suited to Southern Ontario. In good conditions, it is a fast growing tree that begins to bear at an early age. The nuts form in clusters of ten to twenty nuts on the terminals of the branches and fall as they ripen in late September. The best heartnuts have a flattened heart shape that easily split at the seam releasing the kernel in halves. Since not all heartnuts come true from seed, it is important to plant grafted trees of cultivars that have the desirable characteristics.

Though grafted heartnuts begin to bear in a year or two, like most tree crops, it takes a few years before there are enough scaffold limbs to support a commercial crop. In my orchard, twenty-four, eight year olds produced a total crop of 133.9 kg or 295 lb. This was almost double the crop of the previous year. A 15 year old Bates heartnut on the back lawn yielded 48 kg or 105 lb. before drying, after drying the crop weighed 40 kg or 88.2 lb. Table 2 shows the production record of the Bates tree for the past five years.

Five Year Production Record of a Bates Heartnut Tree (fresh weight)
YearAgeCrop (lb)Canopy (sq.ft.)lb/acre
1995 15 105 1500 3049
* Crop record was lost and so estimate was used for 1994.

Bates demonstrates the kind of production that can be attained from a good cultivar. Bates is an older selection that lacks the quality of some of our newer ones. Our best current selections include Campbell CW3, Campbell CW1, Imshu, Pyke, Campbell CWW, Schubert and Fodermaier (for protected long season areas).

Persian Walnut
The Persian walnut originated in the area now known as Iran and Iraq. Over the centuries, it was moved throughout Asia and Europe where it adapted to much colder climates. It is from the colder regions that our Ontario selections have been derived. California selections on the other hand, originated in warm climate countries and so do poorly here. Though our trees are hardy for zone 5, late spring frosts can damage terminal buds that contain the nutlets, and so reduce the crop. They do best in protected regions near the Great Lakes in Ontario.

A number of fine selections exist that equal or exceed the best tasting California cultivars, though it is not likely that we can attain the very high production levels that they get with their Paradox hybrid rootstock. I believe we can offset this by getting a higher price for our fresher tasting, in season product. Good bearing cultivars can easily average one ton or more to the acre. I have often had production levels that reached two or more tons per acre on specific cultivars.

Besides late frosts, production can be limited by walnut blight, a bacterial disease that spoils the nuts. Wet spring weather spreads the disease, so it is important to spray the trees with a copper compound to prevent the spread of this disease. Weekly sprays from bloom in May until mid July are needed to effect control.

We have about 150 Persian walnut cultivars and selections on test in our five acre planting. These trees are evaluated on an annual basis. The table below summarizes the best selections rated over the last five years. The percentage of fill indicates the relative amount of kernel produced in an average year. Smaller, thinner shelled nuts have an advantage in this calculation. All of the nuts in this table have a reasonable percentage for commercial production. Though Cobles 2 has a low fill ratio, its very large size, reliable production and excellent flavour gives it standing in this group as a novelty nut.
Top Orchard Cultivars
SelectionNut Size% FillProduction
Himalaya 3Medium-large53Moderate
Cobles 2Very Large36Moderate

We have a number of other promising selections which include Bedco 1, Harrison, Milotai-10, Grimo 158AA, DiPaulo, and Young's Bl.

The Hazelnut (Filbert)
The European filbert never became a success when it was introduced to Ontario earlier in this century. The Barcelona cultivar was hardy but relatively unproductive and very filbert blight susceptible. The native hazels, on the other hand, were very hardy and often blight resistant but lacked adequate nut size. It was in the marriage of the two that the promise of an adaptable hazel selection could be realized. A number of breeders took up the challenge, producing a variety of interesting selections. We have concentrated our efforts on the Gellatly strain of hybrids as well as the Geneva University (NY) strain. Both strains have developed outstanding selections for nut size, quality, productiveness and hardiness, with variable blight resistance. We are continuing in our efforts to develop selections with all of the above characteristics. In the meantime, it will be necessary to control the blight by pruning out infected limbs and spraying.

Our most productive selections have proven to be Gellatly 502, Laroka, a tree hazel hybrid, arid Grimo 188P (Myoka x Petoka). Though hazelnuts tend to be alternate bearing, Gellatly 502 is the most regular. Table 4 summarizes production over the last five years.

Potential Production of Selected Hazelnuts (fresh weight) lb/acre
Gellatly 502medium2403744917306013781700
Laroka Tree Hazelmedium14546740379016052042
Grimo 188Plarge9729921190178621591420

Some more recent selections that look promising include Grand Traverse, Casina, Willamette, and Skinner. With other newer disease resistant selections on the way, the future looks bright for the commercial production of hazelnuts for Ontario.

Marketing Home Grown Nuts

Europeans and Orientals are a very important target group for hazelnuts, chestnuts, arid walnuts, both fresh and dried. Fresh picked moist walnuts and hazelnuts have a special appeal and command a premium price. Much of the crop can be sold at the farm gate. We easily sell two to three tons of nuts between mid September to Christmas at a price ranging from $2 to $3.50 a pound. Nuts can be sold at city markets or sold wholesale to market gardeners, health food stores or specialty food stores. Ultimately, when the production base is large enough, the nuts can be taken to the Ontario Food Terminal and sold. If this is done early enough, the grower can sell his whole crop and get a premium price, a month or more before the fresh imports arrive. Sampling is a very important part of selling the fresh quality and fine taste of the home grown product. Microwave some chestnuts for them to show how easily they can be prepared or let them crack and sample heartnuts to savour the delicate taste. Give them recipes for utilizing nuts in their diets. Give them research data on the benefits of nuts in the diet for health and nutrition.

Once the fresh market is served, secondary markets can be approached. Shelling plants would need to be established to provide kernels for bakeries, candy makers and retail stores. It would take decades to fill local Canadian needs for both shelled and in-shell nuts.

Provided by SONG. Feel free to copy with a credit.