Part 30 (1/2)
~For Highway Planting~--No other native trees lend themselves so admirably to highway use as the so-called northern or native pecan, the black walnut, and the hickories. These nut trees are all generally well-shaped, reach considerable heights particularly on fertile soils, are stately in appearance, and add beauty and attractiveness to the landscape wherever they are grown.
SOILS AND FERTILIZERS
~Soils Needed for Good Growth~--The nut trees adapt themselves to a very wide range of soil conditions. In fact, few other trees are capable of such a wide range of adaptability to soil types. The uplands usually planted to corn and wheat and the flood plains of the river basins may both be well suited to nut growing.
For good growth and production deep well-drained soils are required.
Under proper conditions the trees develop rapidly, have an extensive root system, and eventually may reach a great age. Furthermore, nut trees cannot grow successfully on wet poorly-drained land where water stands on or just beneath the surface a considerable portion of the year. Lowlands which may be found well adapted to the growth of willow and gum trees, may be too wet and sour for the growth of nut trees. It would also be well to avoid dry, very thin, and very sandy soils.
In their native range the pecan, hickory, and walnut thrive on the alluvial soils of the Missouri and Mississippi River Valleys. They grow well also on the upland sandy loam soils adapted to the growth of corn, oats, and wheat. All of these nut trees are usually influenced more by the fertility, humus, and moisture content of the soil, than by any particular soil type.
~Fertilizers for Nut Trees~--The deep rich alluvial soils of river and creek valleys do not present the same fertilizer problems as light and heavy upland soils. Manure supplemented with superphosphate at the rate of about 20 to 30 pounds to a ton should prove to be a satisfactory fertilizer on depleted soils. It is spread in a circle around the trees extending out about twice the spread of the branches and plowed or harrowed into the soil. A moderate application would range from 8 to 12 tons to the acre.
Leguminous cover crops are particularly valuable for building up the nitrogen and humus content of the soil when plowed under. Their judicious use with non-leguminous cover crops and supplemented with commercial fertilizers to increase the tonnage for plowing under, will usually bring good returns in growth and production.
CARE OF THE PERMANENT PLANTINGS
Since but few diseases and insects attack nut trees in Missouri, very little if any spraying work will be required while the trees are young.
As the trees grow older, however, it may be necessary to give pest control more attention. Caterpillars that infest the foliage of the trees in late summer and early fall can usually be destroyed by cutting off the comparatively few branches on which the worms have cl.u.s.tered and burning them. The pest may also be destroyed on high branches by means of torches. If the trees can be sprayed thoroughly, a.r.s.enicals and other insecticides used in spraying apple orchards will be found very effective while the worms are small.
As in the care of a young apple or peach orchard, it is important that the young trees for at least the first two or three years be given cultivation and some fertilization on lands of lower fertility if a good growth is not being made. A heavy mulch of straw or litter around the trees may prove very satisfactory.
Moreover, livestock should be kept away from the trees until they are established and the branches of sufficient height to be out of danger of injury. It is a serious mistake to plant or grow from seed small nut trees and leave them unprotected from farm animals. If the land is to be grazed, each tree may be guarded with strong posts and barbed or woven wire s.p.a.ced about 8 to 10 feet from the trees.
Once the young nut orchard is thoroughly established and growing thriftily, gra.s.s may be grown beneath the trees and furnish nearly as much hay or pasture as though the trees were not present. If livestock is allowed to graze in the orchard, which is a questionable practice while the trees are young, the trees should be pruned and trained to fairly high heads.
~s.p.a.cing for Nut Trees~--The growing of nut trees for timber alone requires a s.p.a.cing of about 25 to 35 feet apart with other species of trees common to the area growing up later between the nut trees to facilitate the development of tall clean trunks. Under such conditions nut production is inhibited and harvests may be comparatively small. Nut trees grown mainly for nut production rather than for timber may be planted 60 to 80 feet apart on the square plan.
The Thomas black walnut may bear a few nuts the second year following transplanting. Different varieties and species of grafted walnuts, pecans, and hickories often begin bearing from two to four years after setting. Chestnut seedlings may also bear in the second or third year.
Black walnuts from seed sometimes bear a few nuts at 8 to 10 years of age. Profitable bearing, however, may not be expected in the average nut orchard until the trees are at least 10 to 12 years old.
PRUNING WALNUT, PECAN AND HICKORY NUT TREES
For the most part these nut trees do not require heavy pruning.
Superfluous branches, dead limbs, and unsymmetrical ones, should be removed from time to time while the trees are young and becoming established. A uniform top is desirable. The pruning is begun when the trees are 2 or three years old by removing the lowest branches. The rule is to cut away only one branch a year. But trees making a very strong growth may stand more pruning and those making a poor growth may need none.
Cultivation and other orchard practices may be greatly simplified in commercial plantings by pruning and training the tree heads to heights of six or eight feet. Even then the lower branches will ultimately be pressed downward by the weight of nuts and foliage when bearing begins.
Regular annual pruning is required generally to prevent the limbs from interfering with orchard practices. Furthermore, branches lower than six or eight feet high, should be subdued by cutting back while the trees are young. These limbs should be removed ~only~ when the trees have become anch.o.r.ed strongly enough in the soil to prevent the directions of the trunk being influenced by the prevailing winds.
THE BLACK WALNUT
There is something about the distinctive flavor of our native black walnut kernels that appeals to the American people. And there is much about the black walnut tree itself that makes it much admired and respected.
It grows rapidly, and yet it is one of our most valuable timber trees.
It is an excellent tree for the grounds about the home. Not only does it yield an annual crop, but it is a lovely shade tree--beautiful to look at--and has the further advantage that the lawn gra.s.ses grow well beneath it.
~Has Wide Distribution~--It is a very cosmopolitan tree in that it will thrive almost anywhere if given half a chance. From lower Canada to the Gulf of Mexico and from the Atlantic to the Pacific Coast, it may be found in various states of production. On the fertile lands, however, of the Mississippi and Ohio River basins it reaches perhaps its highest development. The 10 high ranking states in walnut lumber production are as follows, in order of their importance: Missouri, Illinois, Kentucky, Ohio, West Virginia, Iowa, Tennessee, Arkansas, Indiana, and Texas.