heartnut is a native of Japan that is well suited to the Great Lakes
fruit growing regions (zone 6), a region similar to its native regions
in Japan. The nut is named after the shape of the nut, as the illustration
shows. It is considered a seed sport of the Japanese walnut and
not a different species. The Japanese walnut is an oval nut, unlike
the heart shaped form of the heartnut. The Japanese walnut usually
cracks out very poorly, making it unsuitable for commercial production.
There are no selected common Japanese walnuts in propagation. They
tend to be hardier than the heartnut form of the nut and so efforts
should be made to find improved cracking Japanese walnut selections
for colder regions. When heartnut seeds are planted, a wide variety
of nut shapes and sizes can be produced by the offspring, from good
and poor cracking types to oval, very poor cracking, typical Japanese
nuts. For this reason, commercial orchards are not advised to plant
seedling heartnut trees, but should plant only grafted trees.
Though the heartnut
tree will grow in colder regions than zone 6, it can be affected
by late frosts. Since the tree is terminal bearing, the nut flowers
are housed in the tip buds of the trees. These buds are the first
to open in the spring and are sensitive to cold spells in April
and May. Frost injured flowers will abort and so reduce the crop.
We only recommend commercial orchards for zone 6. Graft survival
is also best in zone 6 to 7.
tree is best suited to well drained fertile sand and clay loam soils
with a pH of 6 to 7. They are suited to soils where black walnut
and butternut grow wild. They are vigorous trees, growing 50 to
100 cm or more in a year reaching a height of 15 m and a spread
of 20 to 30 m. The large lush compound leaves are largely unaffected
by most insect pests. Grafted trees will begin to bear in 1-3 years,
with commercial production expected in 6-8 years. The trees are
long lived with annual production estimated at 1-3 tons per acre.
trees are selected for several important characteristics.
Quality The nut must crack reliably on the suture (the seam
that holds the shell together) and release the kernel (nut meat)
in one or two pieces. The kernel should fall out easily with no
pieces bound in the shell. Normal shaking and dropping should
allow the kernel to fall free as would occur in a cracking machine.
This cracking characteristic must be consistent from year to year.
The tree must be hardy enough to produce full crops in the
region where they will be grown. Nut set should be high with a
low number of aborts during the growing season. The crop weight
after harvest will be the final consideration. Consistency of
cropping from year to year is also important.
The kernel should be plump and pale yellow in colour. Uniform
pale grey and beige tones are also acceptable. Variable tones
and shrivel are undesirable. The flavor should be mildly walnut
in character with no bitterness.
A number of
selections have been made that meet the above criteria and others
are being tested and evaluated on an ongoing basis.
- This selection was made by John Gordon. It is a seedling of Schubert.
It has rated highly for hardiness, cracking quality and other nut
qualities. It often drops out whole kernels. It is a good producer
of large nuts. It is early season ripening, about September 30 in
the Niagara Region.
CW 1 - Doug Campbell planted Etter seedlings (from the Etter
grove in Pennsylvania). It is rated high for hardiness, cracking
quality, production and nut quality. Kernels are a light golden
colour and drop out in halves reliably. Nuts are a medium size and
ripen about September 30.
CW 3 - Doug Campbell planted this Etter seedling. It is very
similar to Campbell CW 1 in nut and tree qualities. Nuts are slightly
larger than CW 1 and ripens the end of the first week of October.
Nuts drop out in halves.
CWW - Doug Campbell planted this Etter seedling. It also is
similar to CW 1 in nut size, production and nut quality. It ripens
about the same time as CW 3. Nuts drop out in halves.
- This is an older heartnut selection from Dover Plains NY.
It is rated high for cracking quality and production. It produces
a large nut of with good quality. Nuts drop out in halves. It ripens
mid October and being a later nut, it is recommended for long frost
free season areas like the Niagara area.
are only partially self pollinating. This means that two or more
seedlings or different grafted selections should be planted. For
commercial plantings a planting plan like the one shown below will
help growers to establish trees with permanent pollinators in place.
It is advisable to consider field drainage tiles between the rows
and irrigation for prolonged dry spells of 6 weeks or more during
the growing season.
Click here to
view the Heartnut planting