ROADSIDE PLANTING
Prof. A. K. Chittendon
The improvement and beautification of our highways is one of the best investments that can be made. Particularly in the Middle West where we do not have the panorama of hills and mountains, much of the beauty of the road depends upon the roadside trees. They frame the long vistas of farmlands, woods, lakes and rivers and lend enchantment to the road. Under recent legislation Michigan has taken a leading place in the care and planting of roadside trees. Provision has been made by the Legislature for the planting of ornamental and food-producing trees along the highways and for their protection.
The highways offer an almost limitless field for ornamental planting and they also offer opportunities for raising certain food producing trees of which at present the nut trees are the principal species used. A time may come when we can safely plant fruit trees along the roadside but until provisions can be made for their systematic care and spraying, such trees would be liable to spread disease to nearby orchards.
Roadside trees increase the value of adjacent property. They attract birds and thus assist in keeping down insect pests. They may be used to prevent erosion on steep slopes. They increase the life of certain kinds of improved highways by protecting the roadbed from the direct heat of the sun. They serve as a source of food if nut-bearing or sugar-producing trees are used. They invite tourists to travel over the highways. They may serve as a windbreak to prevent the drifting of sand.
Roadside trees may, however, be too close together or by their shade injure crop production in adjacent fields. Some species of trees are particularly harmful if planted on the edge of a cultivated field. They send out their roots under the cultivated land and sap the moisture essential to plant growth. This can be avoided by using trees with deep or compact root systems.
The desirability of planting trees of any sort along the highways is sometimes questioned. There are places where it is urged that trees are not desirable. On stretches of road where the soil is naturally wet the heavy shade cast by certain species of trees is undoubtedly objectionable; but there are also trees whose shade is very light. Some trees make such a dense mass of foliage that they tend to prevent air currents and thus keep the moisture in the road from drying out. Along such stretches of road the method of planting may affect the matter of light and air, and species of trees can be chosen which will be practically unobjectionable. Most of the highway planting in the past has been a matter of chance and there have been few definite plans for any long stretch of roadway.
In selecting trees for planting the probable rate of growth and appearance of the tree at maturity should be borne in mind. What might seem entirely satisfactory in young trees may prove objectionable in the cost of mature ones. The size and shape of the tree at maturity should be considered as it affects the spacing of the trees. Also the amount of care which it will be possible to give the trees should influence the choice of species; for certain trees will produce good results with a small amount of attention while others require a great deal of care. The matter of interference with telephone and electric wires must also be considered. A species should be selected which is relatively free from the attacks of insects and fungi. It would be very difficult to find a tree which is entirely immune but there are some trees which are more resistant than others. The amount of shade cast by the tree is of a great deal of importance in connection with the moisture conditions; trees are often placed too close together which prevents their proper development. Where quick results are desired two species are often used, a fast growing one planted in between slower growing trees; the idea being to cut out the fast growing tree after the slower growing ones have reached good size. This is alright in theory but seldom works well in practice. The fast growing trees are seldom cut at the proper time and the result is often the stunting and injuring of the better and more durable trees. The fast growing trees usually die before many years. The result is seldom satisfactory.
The question of litter while of importance with city street trees does not matter so much in the case of highway trees, but the cottony seed from poplars is very objectionable anywhere. The longevity of a tree is important. The desire for quick results often outweighs other considerations. Many of the trees which give results such as silver maple, box elder and Carolina poplar do not last long and the effort spent on them is wasted. More time and money is needed within a short time to remove and replace such trees. It is better to plant well in the first place. Trees do not grow at the same rate throughout their life. They usually grow slowly at first and then fairly rapidly between the tenth and thirteenth years, after which the rate of growth usually falls off gradually. If small trees, about ten feet high are used for planting they should reach the following sizes in twenty years on favorable soil:
| American elm | 18 | inches |
| Basswood | 15 | " |
| Chestnut | 12 | " |
| Hard maple | 11 | " |
| Red oak | 11 | " |
| Pin oak | 9 | " |
| White ash | 9 | " |
| Black walnut | 8 | " |
| Hackberry | 7 | " |
Certain trees such as the horse chestnut and the evergreens generally appear to better advantage alone or in groups while others like the elms, maples and box elder show to fine advantage in long rows. It is doubtful if the planting of windbreaks along the highways is advisable. Windbreaks are sometimes planted with the idea of preventing the drifting of snow but the snow will collect and form great drifts on the leeward side of a windbreak and the shade from the windbreak may prevent the snow from melting so rapidly. Hedges may be used, however, to prevent the shifting of sand or the erosion of steep slopes.
The highways offer excellent opportunities for nut production and such trees as the black walnut and hickories may often be used to advantage. The presence of birds may be encouraged by planting hackberry and other trees or shrubs of which they are fond.
The Michigan Agricultural College was authorized by the Legislature to raise trees for roadside planting. The College is raising red oak, black walnut, oriental sycamore, sugar maple, elm, hackberry, snowdrop tree, Juneberry, hickory, European larch, Norway maple and box elder for this purpose. Other trees may be added to the list from time to time.
In addition to the planting of trees we need also the proper care of those already planted or growing naturally along the roads. The commonest source of injury is due to improper pruning for telephone lines. A great many trees are badly injured in this way. We already have a large investment in highway trees and it is only the part of wisdom to protect this investment.
Michigan has started active work in highway planting and we hope in a few years to be able to point with pride to our highways, not only because of the good roadbeds but also because of the trees and shrubs that line those roads.
The President: Is there any discussion on Prof. Chittendon's paper? If not, it will be received and filed in the proceedings.
It is now near the noon hour and I think it would be well to have Mr. Jones or Mr. Rush state what program has been arranged for this afternoon.
MR. J. F. Jones: I believe the plan is to get dinner here, and then to go to our nursery at Willow Street. From there some machines will take the parties who do not have conveyances, around to other points.
The Secretary: Mr. President, in accordance with Article V of the Constitution, I move that a committee of five members be elected for the purpose of nominating officers for the ensuing year.
(Motion seconded and carried.)
The Secretary: Mr. President, I move that Mr. Olcott be named the chairman of that committee.
Mr. J. F. Jones, Mr. John Rick, Mr. Ernest M. Ives and Mr. C. S. Ridgeway were nominated as members of said committee.
Messrs. Olcott, Jones, Rick, Ives and Ridgeway having been nominated were on motion duly elected members of a committee to nominate officers for the ensuing year in accordance with Article V. of the Constitution.
On motion the meeting adjourned until 8 p. m. same day.