BLACK WALNUTS
I have spent more of my time cultivating black walnuts than any other
kind of nut tree and given more of my ground area over to them. Yet it
was with no great amount of enthusiasm that I started working with these
trees. Obviously there could be nothing new or extraordinary resulting
from my planting trees of this species either on my farm or at my St.
Paul home, since there already were mature, bearing black walnut trees
at both places. It was only with the idea that they would be an
attractive addition to the native butternut groves that I decided to
plant some black walnut seedlings.
This did not prove feasible as I first attempted it. I had engaged a Mr.
Miller at St. Peter to procure wild black walnut trees for me since they
grew near that town. He was to dig these trees with as much of the root
system included as possible and ship them to my farm. But the winter
season came before this had been accomplished and both Mr. Miller and I,
deciding the idea was not as practical as we had hoped it would be,
abandoned it. Later that same autumn I found that a nursery just outside
of St. Paul had several rows of overgrown black walnut trees which they
would sell me quite reasonably. I bought them and sent instructions to
the tenant at my farm to dig twenty-eight large holes in which to plant
them. Packed in straw and burlap, the trees weighed about 500 pounds, I
found. This was much too heavy and cumbersome to pack in my old touring
car, so I hunted around for some sort of vehicle I could attach to my
car as a trailer. In an old blacksmith shop, I came upon an antiquated
pair of buggy wheels. They looked as though they were ready to fall
apart but I decided that with repairs and by cautious driving, they
might last out the trip of thirty-five miles. So I paid the blacksmith
his asking price--twenty-five cents. The spokes rattled and the steel
tires were ready to roll off their wooden rims but the axles were
strong. My father-in-law and I puttered and pounded, strengthened and
tightened, until we felt our semi-trailer was in good-enough order. It
might have been, too, if the roads in the country hadn't been rough and
frozen so hard that they hammered on the solid, unresisting tires and
spokes until, almost within sight of the farm, one wheel dismally
collapsed. As the wheel broke, the trailer slid off the road into a
ditch, so that it was necessary to send on to the farm for the plow
horses to haul out the car, the trailer and the trees. The horses
finished hauling the trees to that part of the farm where holes had been
dug for them. I had told my tenant to dig large holes and large holes he
had certainly dug! Most of them were big enough to bury one of the
horses in. Such was my amateurish first endeavor.
It was not until December of that year, 1919, that the twenty-eight
trees were finally planted. Although the ground was already somewhat
frozen and the trees poorly planted as a result, most of them started to
grow in the spring. They would probably be living now if I had not been
too ambitious to convert them from seedlings into grafted varieties such
as the Ohio, Thomas and Stabler, which I had learned of during a
winter's study of available nut-culture lore. I obtained scionwood from
J. F. Jones, part of which I put on these abused trees and the remainder
of which I grafted on butternut trees. At that time, I must admit, I was
much more interested in trying the actual work of grafting than I was in
developing or even conceiving a methodical plan to be worked out over a
period of years.
In order to facilitate my grafting work that spring, I pitched a tent in
the woods and lived there for a week at a time, doing my own cooking and
roughing it generally. Cows were being pastured in this part of the
woods and they were very interested in my activities. If I were absent
for a long time during the day, on my return I would find that
noticeable damage had been done to my tent and food supplies by these
curious cows. While preparing some scionwood inside the tent one day, I
heard a cow approaching and picked up a heavy hickory club which I had
for protection at night, intending to rush out and give the animal a
proper lesson in minding its own business. The cow approached the tent
from the side opposite the door and pushed solidly against the canvas
with its nose and head. This so aggravated me that I jumped over to that
part of the tent and gave the cow a hard whack over the nose with my
hickory stick. It jumped away fast for such a big animal. This seemed to
end all curiosity on the part of these cows and I was allowed to carry
on my work in peace.
With beginner's luck, I succeeded with many of the butternut grafts, as
well as with some of the grafts on the twenty-eight planted black
walnuts. However, all of the grafted black walnut trees ultimately died
with the exception of one grafted Stabler. This large tree was a
monument of success for twenty years, bearing some nuts every year and
maturing them, and in a good season, producing bushels of them. One
other of these seedlings survived but as it would not accept any grafts,
I finally let it live as nature intended.
In 1921, I began ordering grafted black walnut trees, as well as grafted
hickory trees from J. F. Jones, who had the largest and best known of
the nurseries handling northern nut trees. Some of these grafted trees
were also planted at my home in St. Paul, using the two locations as
checks against each other. The site in St. Paul eventually proved
unsatisfactory because of the gravelly soil and because the trees were
too crowded. The varieties of black walnuts I first experimented with
were the Thomas, Ohio, Stabler and Ten Eyck, which were planted by
hundreds year after year. If I had not worked on this large scale there
would be no reason for me to write about it today as the mortality of
these black walnuts was so high that probably none would have lived to
induce in me the ambition necessary to support a plan involving lengthy,
systematic experimentation. Some of these early trees survive today,
however, and although few in number, they have shown me that the
experiment was a worthy one since it laid the foundation for results
which came later. In fact, I feel that both the time and money I spent
during that initial era of learning were investments in which valuable
dividends of knowledge and development are still being paid.
In grafting black walnuts on butternut trees, I very foolishly attempted
to work over a tree more than a foot in diameter and I did not succeed
in getting a single graft to grow on it. Other younger trees, from three
to six inches in diameter, I successfully grafted. Some of these are
still living but clearly show the incompatibility of the two species
when black walnut is grafted on butternut. The opposite combination of
butternut on black walnut is very successful and produces nuts earlier
and in greater abundance than butternut does when grafted on its own
species.
The expense of buying trees by hundreds was so great that after a year I
decided that I could very easily plant black walnuts to obtain the young
trees needed as understocks. When they had grown large enough, I would
graft them over myself. I wrote to my friend in St. Peter, Mr. E. E.
Miller, and he told me where I could obtain walnuts by the bushel. Soon
I was making trips to the countryside around St. Peter buying walnuts
from the farmers there. I planted about five bushels of these at the
River Falls farm and the rest, another two bushels, at St. Paul. Soon I
had several thousand young walnut trees which all proved hardy to the
winters.
When pruning the black walnut trees purchased from Mr. Jones for
transplanting, I saved the tops and grafted them to the young trees with
a fair degree of success. In a few years, I was using my own trees to
fill up spaces left vacant by the mortality of the Pennsylvania-grown
trees. I did not neglect seeding to provide stocks of the Eastern black
walnut also, which is almost a different species from the local black
walnut, but these seedling trees proved to be tender toward our winters
and only a few survived. After they had grown into large trees, these
few were grafted to English walnuts. The difference between the Eastern
black walnut and the local native black walnut is quite apparent when
the two trees are examined side by side. Even the type of fruit is
different, although I do not know of any botanical authority who will
confirm my theory that they are different species. They are probably to
be considered as geographically distinct rather than as botanically
different species.
For several years I continued to graft black walnuts on butternut trees
with the intention of converting hundreds, perhaps thousands, of these
wild trees over to prolific, cultured black walnuts. I did not realize
my mistake in doing this until ten years had elapsed. I believed that
since the tops were growing, the trees would shortly produce nuts. Today
they are still growing, bigger and better, yet most of these grafted
trees bear no nuts, having only a crop of leaves. A few nuts result from
these grafts, however, and some of the trees bear a handful of nuts from
tops of such size that one would expect the crops to be measured in
bushels. The kind which bore the best was the Ohio variety. In another
chapter, I shall relate parallel experience in hickory grafting which I
carried on simultaneously with grafting of black walnut on butternut.
My first big disappointment in my black walnut orchard was when, in
about 1930, having a fairly good crop of nuts, I unsuccessfully
attempted to sell them to local stores. They were not interested in
anything except walnut kernels and to them, a wild walnut kernel was the
same as a cultivated one as long as it was highly-flavored. This so
cooled my enthusiasm and hopes for a black walnut orchard that I ceased
experimenting with them except to try out new varieties being discovered
through nut contests carried on by the Northern Nut Growers'
Association. The 1926 contest produced a number of black walnut
possibilities, among them being such named varieties as the Rohwer,
Paterson, Throp, Vandersloot, Pearl and Adams.
The neglected and over-grown walnut seedlings now began to serve a
useful purpose in grafting the new varieties which I obtained for
testing in this locality. These were propagated by obtaining scionwood
from the originators of the variety and grafting it on these seedling
trees. My technical knowledge had increased by this time to such an
extent that I was usually certain of one-half of the grafts growing. The
behavior of the Rohwer and Paterson in 1937 invited nursery propagation
on a greater scale than did other better-known types, because of their
qualities of hardiness and earlier-ripening.
In the spring of 1937, these native seedlings were again offered to the
spirit of propagation, when a large part of the scionwood of English
walnuts I had imported from the Carpathian mountains of Poland was
grafted on them. The success of my grafting in this instance was only
about 1-1/2%, showing that something was decidedly wrong. Two
conclusions were possible: Either the scionwood had been injured by
transportation and the severe winter temperatures during January and
February of 1937 during which they were stored, or incompatibility
existed between the imported walnuts and our local ones. My conclusion
now is that when these stocks are fifteen years old or more and are
thrifty, they will support grafting of the Carpathian English walnuts
much more successfully than they will in their first decade of growth.
Results have shown that these local stocks will accept such grafts,
however, and that crops of English walnuts will be produced. The
fertility of the soil must be maintained carefully, since the English
walnut top tends to overgrow its black walnut root-stock, and unless
nutritional substance for the support of these tops is fed to the
root-system, meager crops, if any, will result.
I might note in comparison to the 1-1/2% success I had in this grafting,
that during the same season I put several hundred scions of these same
English walnuts on the Eastern black walnut stocks without a single
successful graft occurring.
In 1933 and 1934, many of these experimentally grafted walnuts, such as
Vandersloot, Paterson, and Rohwer as well as others, were planted in
orchard formation. In digging these trees, we took care to get all of
the root possible and to take a ball of dirt with the root. In spite of
these precautions, some of the trees died, not having sufficient
vitality and root development to withstand transplantation. This was a
result not only of the crowded condition under which the stocks had
grown but also of the poor soil which had nourished them. The soil was
heavy blue clay underlaid with limestone within two feet of the top of
the ground. Enough trees were set out in orchard formation which are
growing well and bearing annual crops, to give us the proof we need in
drawing conclusions of superiority among these varieties.
Black walnuts will keep for several years if they are properly dried and
then stored in a cool, but not too damp, place. Storing nuts in attics
which are likely to become excessively hot in the summer time, causes
rancidity sooner than any other method. Nuts keep very well in attics
during the winter but they should be transferred to a basement during
hot weather. If the basement is very damp, though, nuts will mould
there. For general storage, without having to move them from one place
to another for different seasons, nuts can be kept most practically in a
barn or outside shed. The only precaution necessary under such
circumstances is that they should be in a box or steel barrel to prevent
squirrels and mice from feeding on them, since barns and sheds are
easily accessible to these animals.
The kernels of black walnuts need not be discolored if the hulls of the
fresh nuts are removed as soon as the nuts are ripe. At my farm, we have
done this with an ordinary corn-sheller. The nuts, having been hulled
this way, are then soaked in water for a few hours to remove any excess
coloring matter left on their shells, after which they are dried for
several days out-of-doors, although not exposed to the sun since this
might cause them to crack open. Thorough drying is necessary before
sacking to prevent moulding. Kernels extracted from nuts treated this
way are very light in color like English walnuts. This enhances their
market value and they command a higher price when they are to be used
for culinary purposes such as cake frosting and candies where there is
exposure of large pieces or halves of the nut kernel. I find black
walnuts are exceptionally delicious when used in a candy called divinity
fudge. The strong flavor of the black walnut kernel although appreciated
by many people, is not as popular as that of the butternut, of which
more is said in another chapter.
The food value of black walnut kernels is high since they are composed
of concentrated fat and protein, similar to the English walnut, the
hickory nut and the pecan. There is also the advantage, which John
Harvey Kellogg of Battle Creek, Michigan, has pointed out, that nuts are
a food of high purity being entirely free from disease bacteria. One
could safely say of unshelled nuts that there is not a disease germ in a
carload.
There was a time when black walnut hulls were purchased by producers of
insecticides. The black walnut hull, when dried and pulverized, produces
a substance which gives body to the concentrated pyrethrum extract which
is the essential ingredient of many insecticides.
One cannot leave a discussion of black walnuts without reflecting on the
furniture which has been possible only through the use of vast forests
of black walnut timber. Beautiful veneers have come from the burl
walnut, being formed by protuberances on the trunks of the trees near
the surface of the ground. There is a variety of black walnut which we
have been experimenting with for quite a few years, called the Lamb,
which has a beautifully figured grain. As this appears only in mature
timber, ours is not yet old enough to show it.
I have found that the Ohio black walnut is prone to hybridize with
butternut trees in its vicinity and others have told me of its
hybridizing with English walnut trees near it, which shows it to be
almost as vacillating in character as our Japanese walnuts or heartnuts.
Ohio black walnuts, when planted, usually produce vigorous stocks, many
of which show hybridity of some sort. If one examines the nuts of the
Ohio and finds them dwarfed or deformed, he may be sure that they have
been pollinized by something other than a black walnut. Planting such
nuts, then, will grow hybrid trees. Most of us have enough curiosity to
want to try this as an experiment.
Thomas walnut seedlings have produced more thrifty trees than Ohio nuts
have. However, the best understocks are those produced from seeds of
native grown trees. It is well understood that rarely does a specific
type such as the Ohio, Thomas or Stabler reproduce itself exactly from
seeds. In raising black walnut seedlings, my experience has taught me
that the nuts should be planted in the fall and not too deep, one to two
inches below the surface being all the depth necessary. They may never
sprout if they are four to six inches under ground. The black walnut
tree is a glutton for food seemingly, it will use all the fertilizer
that it is given although, no doubt, there is a practical limit. It must
have plenty of food to produce successive crops of nuts, and barnyard
manure is the safest and most practical kind to use. This can be put on
as a heavy mulch around the trees but some of it should also be spaded
into the ground. One must always remember that the feeding roots of a
tree are at about the same circumference as the tips of the branches so
that fertilizer put close to the trunk will do little good except in
very young trees. Since 1936 we have been watching a small native
walnut which came into bearing while in a nursery row. This tree bore
such fine thin-shelled easy-to-crack nuts and lent itself so readily to
being propagated by graftage and had so many other good characteristics
that we have selected it as representative of the black walnut varieties
for the north and have named it the Weschcke walnut and patented the
variety. A list is here appended to show the order of hardiness and
value based on our experience:
1--Weschcke--very hardy--excellent cracking and flavor
2--Paterson--very hardy--excellent cracking and flavor (originating
in Iowa)
3--Rohwer--very hardy--good cracker (originating in Iowa)
4--Bayfield--very hardy--good cracker (originating in Northern
Wisconsin)
5--Adams (Iowa)--fairly hardy--good cracker
6--Ohio--semi-hardy, excellent cracking and flavor (parent tree in
Ohio)
7--Northwestern--a new, good hardy nut
8--Pearl--semi-hardy--good (from Iowa)
9--Vandersloot--semi-hardy--very large
10--Thomas--tender to our winters--otherwise very good (from
Pennsylvania)
11--Stabler--tender--many nuts single-lobed
12--Throp--tender, many nuts single-lobed
A friend of mine, who lives in Mason, Wisconsin, discovered a black
walnut tree growing in that vicinity. Since Mason is in the northern
part of the state, about 47 deg. parallel north, this tree grows the
farthest north of any large black walnut I know of. I would estimate its
height at about sixty-five feet and its trunk diameter at about sixteen
inches at breast-height. Because of the short growing season there, the
nuts do not mature, being barely edible, due to their shrinkage while
drying. Some seasons this failure to mature nuts also occurs in such
varieties as the Thomas, the Ohio and even the Stabler at my River Falls
farm, which is nearly 150 miles south of Mason. Such nuts will sprout,
however, and seedlings were raised from the immature nuts of this
northern tree. Incidentally these seedlings appear to be just as hardy
in wood growth as their parent tree. I have also grafted scionwood from
the original tree on black walnut stocks at my farm in order to
determine more completely the quality of this variety. Since grafted,
these trees have borne large, easy to crack mature nuts and are
propagated under the varietal name (Bayfield) since the parent tree is
in sight of Lake Superior at Bayfield, Wisconsin.
Many of our best nut trees, from man's point of view, have inherent
faults such as the inability of the staminate bloom of the Weschcke
hickory to produce any pollen whatsoever, as has been scientifically
outlined in the treatise by Dr. McKay under the chapter on hickories. In
the Weschcke walnut we have a peculiarity of a similar nature as it
affects fruiting when the tree is not provided with other varieties to
act as pollinators. It has been quite definitely established, by
observation over a period of ten or more years, that the pollen of the
Weschcke variety black walnut does not cause fruiting in its own
pistillate blooms. Although this is not uncommon among some plants, such
as the chestnut and the filbert where it is generally the rule instead
of the exception, yet in the black walnuts species the pollen from its
own male (or staminate) flowers is generally capable of exciting the
ovule of the female (pistillate) flower into growth. Such species are
known as self-fertile. As in the case of ordinary chestnuts which
receive no cross pollination, and the pistillate flowers develop into
perfect burrs with shrunken meatless, imperfect nuts, the Weschcke black
walnut, when standing alone or when the prevailing winds prevent other
nearby pollen from reaching any or but few of its pistillate bloom, goes
on to produce fine looking average-sized nuts practically all of which
are without seed or kernels. Such therefore is the importance of knowing
the correct pollinators for each variety of nut tree. In the
self-sterility of filberts the failure of self-pollination results in an
absence of nuts or in very few rather than a full crop of seedless
fruits such as the common chestnut and the Weschcke black walnuts
produces. This is the only black walnut that has come to the author's
attention where its pollen acting on its pistillate bloom has affected
the production of nuts in just this way but the variety of black walnut
known as the Ohio, one of the best sorts for this northern climate
except for hardiness, has often demonstrated that it has a peculiarity
which might be caused by lack of outside pollen or because of the action
of its own pollen on its pistillate bloom. This peculiarity is the often
found one-sided development of the Ohio walnut kernel when the tree is
isolated from other pollen bearing black walnuts. One lobe of the kernel
is therefore full-meated while the other half or lobe is very
undernourished or it may be a thin wisp of a kernel as is the appearance
of the Weschcke variety in similar circumstances.
[Illustration: _Stabler variety of Black Walnut grafted on a Minnesota
seedling stock bore many years but was winter killed. Photo by C.
Weschcke_]
Cutting scionwood early one spring, I noticed that the sap was running
very fast in the grafted Stabler tree previously referred to. Later when
I came back to inspect this tree, I noticed that the sap had congealed
to syrupy blobs at the ends of the cut branches. My curiosity led me to
taste this and I found it very sweet and heavy. I mean to experiment
some time in making syrup from the sap of this tree as I believe its
sugar content to be much higher than that of the local sugar maple. This
makes the Stabler a 3-purpose tree, the first being its nuts, the second
being the syrup, and the third being, at the end of its potentially long
life, a good-sized piece of timber of exceptionally high value. The tree
is one of beauty, having drooping foliage similar to that of the weeping
willow. This is another point in its favor, its being an ornamental tree
worthy of any lawn. However, the Stabler is now considered as a tender
variety and is not recommended for northern planting.
[Illustration: _Stabler graft on old seedling grafted in May, 1938
bearing in August of the same year. Photo by C. Weschcke_]
[Illustration: _Cut Leaf Black Walnut. Scions furnished by Harry Weber
of Cincinnati, Ohio. Variety was hardy on Minnesota seedling for about 5
years. Photo by C. Weschcke_]
The aesthetic value of the black walnut does not cease here since there
are some varieties which are exceptionally attractive. One of these is
the cut-leaf black walnut which has the ordinary compound leaf but whose
individual leaflets are so scalloped and serrated that they resemble a
male fern. Everyone who has seen one of these has evinced pleasurable
surprise at this new form of leaf and it may become very popular with
horticulturists in the future. Another interestingly different variety
is the Deming Purple walnut which, although orthodox in leaf form, has a
purplish tint, bordering on red in some cases, coloring leaf, wood and
nuts, resulting in a distinctly decorative tree. This tree was named
for Dr. W. C. Deming who was the founder of the Northern Nut Growers'
Association. Neither the Laceleaf nor Deming Purple are hardy for this
climate but survived several years nevertheless before succumbing to one
of our periodical test winters.