TREE PLANTING METHODS
Since nut trees usually have deep, well-developed root systems of the
taproot type, they are more difficult to transplant than such trees as
plum, apple, elm or maple which have many small fibrous roots. Taproots
have a long, main trunk like a parsnip, from which lateral roots branch.
These roots are heavy and may extend deep into the ground even in trees
only two or three years old. In moving such a tree, the lower part of
the central taproot must, of course, be cut off, but as many of the side
roots as possible are retained. Because such roots have no fibrous or
hair-root system, their handling during transplantation necessarily
differs from that of the ordinary shade or fruit tree.
If trees having a taproot system, such as the English walnut, black
walnut, butternut, hickory or pecan, are received with bare roots, they
should be treated in the following way: Immediately after the trees have
been unpacked, their roots should be submerged in a barrel of water for
several hours. After their thirst has been quenched, the roots should be
dipped into a mixture of clay and water made to the consistency of thick
paint. With a heavy coating of wet clay around them, the roots may then
be wrapped in wet burlap sacks. They are now ready to be transported to
their planting site.
Selecting a favorable location for nut trees is very important. They
should never be planted at the bottom of a gulch or valley because, in
such places, frost pockets may occur which will interfere with both
blossoming in the spring and ripening of nuts in the fall. Nut trees
grow best near the summit of a hill. Although such soils are difficult
to plant in, stony soil or soil overlaid with limestone results in good
growth. Shallow surface soil, underlaid with heavy clay, will usually
slow down the growth of a young tree so that it remains dwarfed for many
years. It is more satisfactory to have at least three feet of soil
before clay is reached. If the soil is light and sandy, it will be
improved by adding black dirt immediately around the roots of each tree.
As most nut trees ultimately grow to be very large, they should be
planted at least forty feet apart. The hole dug to receive each tree
should be wide and deep enough to accommodate the roots without bending
or twisting them. If the excavated soil is of poor quality, it should be
discarded, and good, rich soil brought in for setting the tree. Trees
should not be planted too deeply. The collar of a tree, which is a
discoloration of its trunk resulting from contact with the ground,
indicates how much of the tree was previously underground. Although it
is a good idea to plant so that this collar is a little lower than the
surface to allow access to extra moisture, the actual planting depth
should be about as it was previously in the nursery. All broken or
damaged parts on the roots should be trimmed smoothly with pruning
shears. Such clean cuts will send out new rootlets to replace the lost
ones. After a tree has been set into the hole made for it, the soil,
which should be thoroughly mixed with a quart of bone meal to increase
its fertility, is replaced a little at a time. It must be packed very
solidly about the roots with a rounded tamping stick to avoid leaving
air pockets. I find it advisable to retamp the earth about each tree two
or three times during the first year's growing season, to insure
intimate contact between soil and roots.
Planting should be delayed if the soil is very wet. Trees will stay in
good condition for several days, if the burlap sacks are kept moistened.
Wet, soggy soil is certain to shrink away from the roots and leave air
pockets which will, in time, kill the trees. If trees are transplanted
during a very dry season, they should be thoroughly watered. To do this,
remove several shovelfuls of dirt from the ground about a foot from the
tree, being careful not to cut any roots. Fill this hole with water and
after the water has seeped away, fill it two more times. The tree should
receive about five gallons of water. Sprinkling with a hose does not
suffice. If dry weather continues, each tree should be watered in this
way every week.
Nurserymen in the future will have to deal with this transplanting
problem in a different way than the old time nurserymen who handles
fruit trees. A suggested way to improve the root system and at the same
time make it easy to lift the tree with a ball of dirt, similar to the
way an evergreen is transplanted, is to prepare a pocket of special
transplanting soil previous to the lining out (which is the term used by
nurserymen in setting out seedlings preparatory to grafting them in
nursery rows). A suggested balanced soil for making the method practical
is to use 1/2 by volume of peat moss; the other half should be rich,
black sandy loam with very little clay mixture in it. In other words,
each nut tree should be allowed about a bushel of soil for its
development, 1/2 bushel to be peat moss, the other half bushel to be
represented by rich black loam. This mixture will encourage many
fibrous roots to develop and when the tree is dug, approximately all of
this bushel of soil will be retained around the roots. Having such a
high proportion of peat moss makes it lighter than ordinary ground; such
a ball and the tree will weigh approximately from 100 to 125 pounds
which can be shipped by freight at a low rate and is well worth the
extra price that nurserymen must ask for a specimen of this kind. Such
trees have really never been unplanted and for this reason do not suffer
the shock which is inevitable in the usual transplanting process.
Although pre-planted trees are more expensive to buy and to transport,
their improved chances of living make them worth the price. The above
recommendation is especially applicable to young grafted hickory trees
since they are among the most difficult trees to transplant
satisfactorily. The English walnut (Persian), black walnut, butternut
and especially the hickory are improved by the use of a handful of
ground lime mixed with the soil in preparing these pockets which will
later constitute the ball surrounding the roots of the tree to be
transplanted.
There is a tendency in grafted trees to produce sprouts below the graft.
Unless these are rubbed off, the grafted portion will become discouraged
and the tree will revert to a seedling variety. Filberts should never be
allowed more than two or three stems, or trunks, while one is more
preferable. If they are allowed to have more, they will produce a rank
growth of wood but only a few, if any, nuts. I stress, by repeating,
that trees should not be planted too deeply and that great care must be
taken to eliminate air pockets. Extra effort and nursing of transplanted
trees during the first season will be repaid by their successful
development and growth.
It is a wise precaution to place a protective screen around the trunk of
each tree to prevent rodents from attacking it. Mice gnaw off the bark
near the ground, sometimes girdling a tree and so killing it. Rabbits
chew off branches and they, too, may girdle the upper part of a tree.
Rabbits are very fond of pecan and hickory bark. In some places, it may
be necessary to encircle each pecan and hickory tree with a three or
four-foot rabbit fence until the tree is large enough to lose its appeal
to these nuisances.
Compared with the number of insects which infest fruit trees, very few
attack nut trees. One of those which does is the walnut-leaf
caterpillar. These appear as a closely congregated group of small worms
which feed on the leaves of black walnut and hickory trees during the
latter half of the summer season. Very often they are all to be found
on a single leaf, which should be picked from the tree and crushed
underfoot. A simple spray of lead arsenate of the strength recommended
by companies selling spray material, will effectively rid trees of these
pests. Another insect often found in a nut orchard is the oak tree
girdler, which also is active in the latter part of the summer. It often
causes limbs as large as an inch in diameter to be cut through and to
fall to the ground. By removing such freshly girdled branches and
cutting into the hollow made by the larva, it is possible to find the
live worm and destroy it. A good way to combat this pest is to keep each
tree pruned of all dead branches and to burn all broken and dead wood
each fall. While some nut trees are subject to other insects, the two
described here are the most frequently found. Fortunately, they are
easily controlled if a watch is kept for them.