Growing Nuts in the North Part 8

It would be well from time to time to inspect these seeds to see whether they were in good condition and check the temperatures as well. If they start to sprout all the better; they can then be planted with the sprout downward and the nut barely covered with earth. Some years I have had sprouts nearly six inches long on my chestnuts which had been so stored and care will have to be taken not to break the sprout when transplanting the nuts.

In planting nuts, great care must be taken not to plant them too deeply.

Large nuts, such as black walnuts, b.u.t.ternuts and English walnuts, are often planted with a small part of the nut still exposed. Certainly, the depth of the soil over a nut should never exceed the thickness of the nut. Most seeds develop best when they are planted just under the surface of the soil. The earth should be lightly tamped around the planted seeds to eliminate air-pockets. A thin coating of manure, not more than three inches deep, is valuable if large seeds are planted but it is detrimental to the development of small seeds and manure should never be used for evergreens. Seeds of the nut pines, usually purchased from seedsmen and received in a dry state, should be planted no deeper than their own diameter in a light, sandy loam. A seed bed, incidentally, is a very necessary protection against rodents in the case of nut pine seed. I have used a mixture of bone meal on such seeds with good results. Four quarts of bone meal carefully worked into the first two or three inches of the surface soil of a 4 x 12 seed bed greatly increases its fertility. Sifted hardwood ashes scattered over the bed after the seed is in, will discourage cutworms and increase the potash content of the soil.

Proper drying and storage are of no use if nuts are not planted where they will have protection against rodents, improper drainage, and other hazards. To keep them from being eaten by rodents, nut seeds should be planted under wire screens inside a deep frame. The seed beds I have made for use in my nursery are four feet wide and twelve feet long. By using heavy galvanized hardware cloth 2 x 2 mesh, which means that it has 1/2-inch square holes, is ideal for the top and sides of this frame.

By using this wire cloth 2 feet wide, 18 inches is sunk under the ground surface, and only 6 inches protrudes above. This is to prevent burrowing rodents from going underneath and extracting the seeds which you will find they will do unless the screen protection goes down deep enough into the ground to discourage them. A stout frame of rot-resisting wood, such as cedar or fir should be placed on the inside of this countersunk screen. This should also be 4 feet wide, 12 feet long so that a similar frame, which is removable, can be placed over this. The edges of the frame should match perfectly so that no rodents can reach the interior of the seed bed without going down 1-1/2 feet under ground to burrow under the countersunk screen. Several thousand evergreens or several hundred walnut trees can be raised in a seed bed this size.

The soil is now removed from the inside of this enclosure or stationary part of the bed to the depth of 6 inches so that the plants will have head room to develop leaves and stems and still be protected under the top or removable frame part. The top frame made of the same material and covered also by the 2 x 2 hardware cloth should be about 6 inches in height so that there will actually be 18 inches of head room for the plants to grow in before touching the screen.

[Ill.u.s.tration: _This 60 x 30 foot corrugated galvanized iron fence 3-1/2 feet tall and sunk 6 inches into ground protects valuable hybrids against invasion by rodents. Photo by C. Weschcke._]

There are several important points to remember in starting a seed bed.

It must be in a well-drained site, so that the seeds will not be under water or water-logged for any length of time. It should be in an open place where sunlight is plentiful, unless evergreens are being grown.

Evergreens must be in half-shade the first season to avoid a condition known as "damping off." The top six inches of soil in the bed should be the best garden soil obtainable, the growth resulting from using good, clean soil, free from weed seeds, being worth the trouble of preparing it. By having the bed in two parts, with a cover that may be taken off, proper weeding can be done when necessary. The cover should always be replaced afterward, though, as rodents will sometimes attack the young shoots and the remainder of the seed kernel.

In the spring of the second season of growth, the young plants may be dug up and lined out in nursery rows. After two or three years more, they may be planted in permanent locations.

Chapter 13

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, b.u.t.ternut, 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, b.u.t.ternut 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 const.i.tute 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 a.r.s.enate 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.

Chapter 14

WINTER PROTECTION OF GRAFTS AND SEEDLINGS

It is not enough to make a successful graft and to watch it carefully during the growing season, picking all sprouts off the stock, spraying it so that insects will not chew the tender leaves and bark, bracing it against windstorms and perching birds. Each graft must also be protected from winter injury. For many years I have studied and experimented to find a successful way of achieving such protection. To enumerate my many experiments, from simple to far-fetched, would be to write another book quite as long as this one. My conclusion, now, is that there is little one can do to a.s.sist nature in the process of acclimatizing grafted plants and seedlings.

I have repeatedly noticed that the place where most damage is done by the cold is at the union between stock and graft. For example, I observed this on the European walnuts, imported from Poland, grafted to Minnesota black walnut stocks. Although both the buds and the wood of the top remained fresh and green, the unions suffered severe, and sometimes total winter injury. In grafts where the latter occurred, the dead cells soon caused the wood to ferment and sour. Occasionally, a small group of healthy cells succeeded in re-establishing circulation with the unharmed, grafted top and the graft, continuing its growth, would eventually overcome the injury it had suffered. I have seen this occur with grafts of English walnut, apricot and pecan.

A blackbird's nest in the crotch of a small tree suggested to me the most satisfactory guard I have yet found against this greatest of dangers to all exotic, grafted varieties of nut trees. The nest, which enclosed over half of the graft union, was partly composed of woolen fibers which its builder had gathered from barbed-wire fences that sheep had brushed against. On the exposed portion of the graft union, discoloration indicated injury and dead cells, but on that part covered by the nest, all the cells were alive and green. I have improved on the bird's nest by wrapping a large wad of wool loosely around each graft union. The value of wool is that it will not collect moisture and so start fermentation. It allows the cells to breathe, yet protects the union from the shock of temperature extremes. Birds will inevitably steal some of the strands of wool but this activity in and about the trees means a decrease in injuries from insects--a worthwhile exchange.

When an unusually large swelling at the graft union appears, it is certain that the plant needs protection such as I have described. Such swellings result from a too-rapid multiplication of cells, a condition which leaves the union weak and susceptible to injury. Although a union is never entirely safe, even after many seasons of growth, each year adds to the safety factor by the development of rough, cork-like bark. I suggest the use of a woolen guard for several winters, by which time this outer bark should be able to do its protective work alone.

A successful but rather expensive method of winter protection, both to the graft itself and its union with its host, is to enclose the entire tree with a box-like structure consisting of four corrugated aluminum roofing sheets set up on their ends and countersunk into the ground about six inches. The purpose of countersinking these below the ground surface is two-fold: it stiffens and braces the structure and prevents the intrusion of mice and other rodents, which may also appreciate both the shelter and possible food supply contained therein. By fastening these sheets together with a stout wire you can depend on the structure to stand up against wind and snow pressures. Fill the entire inside with forest leaves, oak leaves preferred, as their insulating quality is the best and they are slow to rot and ferment.

When working with semi-hardy plants in a cold climate, avoid fertilizing and cultivating the ground after the first of August. Doing so stimulates late growth and such growth is very likely to be badly injured during the winter months. If fertilizer is used, it should be early in the spring, as soon as the ground is free from frost. Trees which persist in growing late into the fall are more subject to winter injury. Protective measures to avoid their doing so by inducing an earlier dormancy, include keeping the soil around them dry and exposing, somewhat, the roots near the trunk of each tree.

My last word of advice in raising what might be termed semi-hardy trees, is to grow them in sod, the ordinary quack gra.s.s, June gra.s.s, bluegra.s.s or other natural gra.s.s sods which can be found on your planting site.

Although this will probably hold back your tree development for a few years, until the roots are thoroughly established in the deeper soil beneath the sod roots, it is surprising how many species of trees will thrive in sod and perish on open cultivated ground. I can give no better example of this than relating a circ.u.mstance which bears this out in a most convincing way. In 1941 I purchased about 250 filbert seedlings from Samuel Graham of Ithaca, New York. These were planted out on a field site and practically all of the plants made good growth the first year. They were thoroughly cultivated. The next year a second batch of plants of a like amount were purchased from the same man and of the same kind of seedlings. Mr. Graham told me that these were seedling trees from Jones hybrid seeds which he had growing in his orchard. These plants were put on heavy sod ground; all plants were protected by screens, but the plants on the sod ground were subject to a very wet season and it was necessary to build up the soil around some of the plants in order to save them from being drowned out. Today about 45 plants are living on the sod culture and two or three barely alive exist in the open field culture. Although the plants remaining alive on the sod culture plot are almost pure filbert strain they are therefore very subject to the common hazel blight. Some have grown into bushes 10 feet high which later were hit by blight and have been reduced to small bushes. Others are producing good filbert-type nuts and are somewhat blight resistant, but the main fact to remember is that about 1/4 of the plants on sod culture lived, whereas not over 2% are alive of the open field culture plants. The distance between these plantings is approximately 1/8 of a mile. In addition to being placed in sod these filberts which have survived are sheltered by rows of evergreen trees both on the south and on the north side which may be construed as of some a.s.sistance but is not altogether the reason for the tremendous difference between the winter protection value of sod and open field culture. This is not the only example that I could cite but is one of the most outstanding ones which has come to my attention. Sod culture is now being recommended to fruit orchardists in this part of the country and in my own experience, I can highly recommend it for apples, plums, pears, mulberries and nut trees.

Chapter 15

TREE STORAGE

If it is necessary to store trees through the winter months, one of several procedures may be followed. If the trees are quite small, their tops may be dipped in melted paraffin or beeswax, not hot enough to injure the buds. If the trees are too large for this to be practical, wax may be painted on with a brush. Roots should be protected by heeling them in dirt.

An unheated cellar with a dirt floor is a very satisfactory place for storing trees. Select a corner of the cellar far from any source of heat or temperature change. Place the trees so that the roots are pointing toward the bas.e.m.e.nt wall. Cover the roots to a depth of six inches with either sand or sandy loam, packing the soil firmly to eliminate air pockets. Lastly, cover the trees completely with burlap sacks. Once every two weeks, the earth around the roots should be watered. Trees maintained in this way are conveniently ready to plant when the ground thaws out in the spring.

Another and better method of storing trees is to plant them outside in a trench, preferably on the north side of a building, having first waxed them as described above. One side of the trench should slope so that the trees will lie in an oblique position with their branches touching the ground. The roots of these trees should be covered with dirt, then more trees set alongside them, until all have been planted and the earth made firm about their roots. Trees will usually suffer no damage during such winter storage if their roots have been properly packed in sand or sandy loam. Six or more cans, each containing a little poisoned grain, should be set among the branches. If these cans are laid on their sides, rodents will have easier access to the poison. The branches of the trees should then be well covered with straw or hay, with heavy boards laid on top to keep it from blowing away. If trees are received for planting after the ground has frozen, all that is necessary is to build a log fire on the side where they are to be heeled in. This will thaw out the soil enough so that a trench can be made to accommodate them.

Chapter 16

SUGGESTIONS ON GRAFTING METHODS

Grafting, including budding, may be defined as inserting a piece of wood which carries buds of a desired variety, on a root stock sufficiently compatible to accept it, for the purpose of propagation. Methods vary, each nurseryman having one or more which he prefers, but the principle is always the same.

Scionwood may be cut the fall before grafting is to be done, after the growing season has ended, but some prefer to cut the scions in early spring. This means that the scions must be stored until time to graft, and correct storage is so important that nurserymen make elaborate provision for it. I have found that keeping scions underground in a Harrington graft storage box is the safest method. An ill.u.s.tration of this box is given, with directions for its construction and location. A small quant.i.ty of scions may be kept in an icebox (not a mechanical refrigerator), by cutting them into convenient lengths of one or two feet, dipping them in melted beeswax, wrapping them in tar or asphalt paper and placing them close to the ice. They will remain in good condition for several months if there is always a good supply of ice.

Care must be taken in dipping the scions in melted wax, for if the wax is too hot it will injure the buds. It should never become so hot that it smokes. I find it advisable to keep an unmelted piece of wax in the liquid wax to hold the temperature down.

Another method of storing scions, after they have been dipped in beeswax, is to place them on the earth of a cellar floor and cover them with a few burlap sacks. They should never be allowed to become wet or they will start to mold. If they are to be stored in this way, a watch must be kept for mice which will molest them and destroy them if they have an opportunity.