Dr. J.A. Neilson,
walnut, Juglans sieboldiana (ailantifolia*), and its varietal
form cordiformis, were said to have 'been introduced into America
from Japan about 1870 by a nurseryman at San Jose, California. From
this and other subsequent introductions a considerable number have
been grown and distributed in the United States and Canada.
A recent inquiry
by the writer brought forth some interesting data relative to the
occurrence and distribution of this species in North America. This
inquiry shows that it has been widely distributed. and is reported
in the following states: Arkansas, Arizona, Alabama, Connecticut,
California, Delaware, Illinois, Iowa, Indiana, Kentucky, Massachusetts,
Missouri, Minnesota, Maryland, Maine, Mississippi, Michigan, New
Jersey, New York, New Hampshire, Ohio, Oregon, Pennsylvania, Rhode
Island, Vermont, Virginia, West Virginia, Washington, and Wisconsin.
No reports were received from Carolina, Louisiana, Montana, North
Carolina, North and South Dakota, Idaho, Georgia, Colorado, Kansas,
Texas, and Wyoming, and negative reports were received from Florida,
New Mexico, Nevada, Oklahoma, and Tennessee.
In none of
these states is the Japanese walnut abundant in the same degree
as other kinds of nut trees, but in some states it was reported
more frequently than in others. It occurs more abundantly in Pennsylvania,
New York, Connecticut, New Jersey and Delaware than in other states.
In Canada it
has been reported, from Prince Edward Island, Nova Scotia, New Brunswick,
Quebec, Ontario, Manitoba, Alberta and British Columbia. In Ontario
it is found occasionally from Windsor to the Quebec boundary and
from Lake Erie to North Bay. There are several fine large trees
in southern Ontario, some of which are worthy Of Propagation. Many
of the trees in Ontario and other eastern provinces grew from nuts
distributed by the writer several years ago. For five years in succession
the writer bought the crop from a. large heartnut tree near Jordan
Station, Ontario, and distributed the nuts all over Canada to those
who were interested. More than twelve thousand nuts were thus distributed
and I know from observation and reports that seedling trees are
now growing from the Atlantic to the Pacific. I am going to tax
your credulity to the utmost and tell you that one of my correspondents
reports heartnut trees growing in the Peace River area of northern
Alberta. 1 have no recent report from my friend but 1 know that
the trees came through two winters in that far northland.
the days to come a superior seedling or a hybrid may be found in
these numerous seedlings which will be worth propagating. Some of
these trees have already borne nuts and many have made very good
walnut has also been reported from New Zealand and several states
in Australia, England, France, Germany and other European countries.
From the foregoing
it can be seen that this species of walnut has been widely distributed
and is now growing in countries with a wide temperature range. Reports
are on hand which show that the trees have endured temperatures
of 40 below zero F. to 110 above zero. From this it need not he
assumed that all Japanese walnut trees will stand great extremes
of heat and cold, for experience shows that they will not. It does
show, however, that some individuals at least have marked hardiness
to cold and bent and have endured temperatures much greater than
the English walnut. The best results in growth and fruitfulness
have been obtained in those regions of moderate rainfall where the
apple and sweet cherry grow successfully.
walnut seems to thrive on many soil types ranging from a heavy clay
to a light sand, but does best on what is popularly known as a well
drained fertile sandy loam with a friable clay subsoil. lt will
not do well on strongly acid soils and those who have planted trees
on such soils should apply lime in liberal quantities. Poorly drained
soils or very light soils deficient in humus are also not suitable.
walnut has several characteristics which make it desirable as an
ornamental and as a nut-bearing tree. It grows rapidly, has large
numerous luxuriant leaves which give it a tropical effect, and usually
has a symmetrical outline. It bears early, sometimes in the second
year from the graft, yields heavily and is often reported to yield
tree owned by Mr. Silvester Kratz of Jordan Station, Ontario, produced
nearly seven bushels of husked nuts one season and Mr. J. W. Hershey
reports a yield of ten bushels of heartnuts from a tree near Olney,
Pennsylvania. He also reports a cash return of $50.00 from one tree
grown by Mr. Killen of Felton, Delaware. These were heartnuts and
sold for 50 to 75 cents a pound. Mr. J. U. Gellatly, Westbank, B.
C., obtained a yield of ten bushels of unhusked nuts from a heartnut
tree of medium size. The yields from the common type, J. sieboldiana,
have also been heavy, but since no figures are available no definite
statements can be made.
In the Japanese
walnut as in other species of nuts there is marked variation in
nut characteristics, such as size, thickness of shell, cracking
quality, extraction quality and flavor of kernel. Heartnuts have
been found ranging from ½" to 1 ¾" in length.
The largest heartnut I have ever seen came from Gellatly Brothers
of Westbank, B.C. This nut was 1 3/4 in. long by 1¼ in. wide
and was fully 1 in. thick. 1 also located a fine Sieboldiana type
which is said to be the largest. found up to date.
Some of these
good kinds possess excellent cracking and extraction quality. Mr.
John Hershey of Downingtown, Pa., reports several good easy-cracking
strains not yet introduced and Mr. Gellatly has one called 0. K.
that can easily be cracked with a hand nut cracker. I have also
found one that 1 believe is a hybrid and which has excellent cracking
and extraction quality. These specimens came from a seedling heartnut
grown by Mr. Claude Mitchell, Scotland, Ontario. The nuts are longer
than any heartnut found so far. The kernels in many cases fall out
whole or in halves. This strain received the 0. K. of Prof. Reed
and Dr. Deming and as you know when a nut gets by either of those
gentlemen it has to possess some merit. The good result produced.
by nature without any assistance from man suggests the possibility
of getting even better results from parents of superior characters.
I. believe the Japanese walnut offers interesting possibilities
in breeding with the butternut and possibly the black and English
walnut. Definite plant breeding work should be done with these species
as well as with all other species of nuts.
walnuts generally grow fast but usually do not attain a large size.
In most cases the trees rarely grow more than 35 feet tall with
a spread of 30 to 50 feet, but occasionally specimens attain much
larger size. The writer saw a heartnut tree on Mr. Kratz's farm
near Jordan Station, Ontario, which had a trunk diameter of 2 ft.,
a height of 35 ft., and a spread of 64 ft. Near St. Thomas, Ontario,
there is a large sieboldiana tree which is 75 ft. across the top
and is about 45 ft. tall. Mr. Ricks. reports a huge tree near Olney,
Pennsylvania, that is 80 ft. across the top and 60 ft. tall and
Dr. Deming reports a tree with a spread of 100 ft.
efforts of the Northern Nut Growers Association members several
good varieties have been found and propagated. These varieties have
been widely distributed but have not been extensively planted. The
results are variable is might be expected, but generally the reports
are satisfactory. In the eastern states the following varieties
seem to do reasonably well: Faust, Bates, Ritchie and Stranger.
In British Columbia, Messrs. J. U. and David Gellatly have located
several very good strains such as Gellatly, 0. K., Calendar, Walters
and Rosefield. These newer varieties from the West have several
good characters and are worthy of a wider trial in the East.
and Insect Pests
In common with
most other forms of plant life the trees are susceptible to some
insects and diseases. Reports of injury by the walnut weevil, Conotrachclus
juglandis, and also, by codling moth larvae have been received.
In some cases the foliage is attacked by rust fungi and some injury
is also done by leaf spot. Prof. Reed reports witches broom attacking
some trees in the south and one case of this disease was observed
by the writer in Ontario on a Siebold-butternut hybrid. Notwithstanding
these defects it is believed that the Japanese walnut is less attacked
by disease and insects than most other species of nut trees.
of a group of people on the merits or defects of a tree species
or project is worthy of consideration. In order to get an expression
of opinion as to the merits of the Japanese walnut the following
question was asked: Do you consider the better strains of Japanese
walnut worthy of more extended planting? The answers to this inquiry
were numerous and varied. The great majority were in favor of increased
plantings but a few were somewhat dubious. Nearly every one agreed
that the species possessed marked beauty and was worthy of more
extended planting as an ornamental. Some gave preference to the
nuts over the black and English but the majority thought the quality
was not quite up to the standard of these two species. Some observers
reported favorably on the heartnut for culinary purposes and as
an ingredient of ice cream and candy. With these latter comments
I have had personal experience and can heartily agree.
From the evidence
furnished by correspondents and from personal observation, the good
qualities of the Japanese walnut may he summed up as follows: Rapid
growth, marked beauty of form and foliage, early bearing, productiveness,
and more than average hardiness to winter cold. The nuts from superior
trees are easier to crack than the butternut, hickory and black
walnut, but not so easy as the pecan and Persian walnut.
varieties yield nuts with a mild f1avor which appeals to the taste
of many people, but others think the flavor is not quite pronounced
crosses readily with the butternut and offers interesting possibilities
for the plant breeder.
The trees appear
to be somewhat less susceptible to insects and diseases than other
walnuts, but this may not always hold good.
of the Japanese walnut most frequently mentioned are lack of flavor
and pollination deficiencies. Some trees produce staminate flowers
too early for proper pollination and thus do not yield a crop unless
another good pollinator grows nearby.
to sun-scald and to San Jose scale are some other weaknesses. Many
of the trees commonly grown are undesirable because of small size
of nuts, poor cracking quality and too mild a flavor.
A careful consideration
of the good and bad. characters of Japanese walnuts suggests the
following program before the culture of this species can be placed
on a sound basis.
- A systematic
and thorough search of the United States and Canada for productive
trees yielding nuts of large size, of good cracking and extraction
quality and pleasing flavor.
- The propagation
and wide dissemination of these superior strains to members of
the Northern Nut Growers Association and particularly to experiment
stations where there seems to be a striking lack of information
on this and other species of nuts.
improvement by means of hybridization with the butternut and other
A program such
as this would yield. information of great value and would probably
establish the culture of this species on a sounder basis than it
now is.. Until this has been done the logical course to follow is
to plant the best varieties in limited numbers in areas where the
black walnut thrives and even in areas too cold for the black walnut.
* current nomenclature
the 21st Annual Report (1930) p. 39-45.