The Birmingham age-herald., 1914-11-08
Number of Points to Be Considered When Select
 ing Street Trees
HARDNESS IS ONE
 OF CHIEF FACTORS
Must Be Able to Thrive Under Ad- verse C0nditions-Straight and Symmetry of Growth-Trees Best
 Adapted 10 This Climate

Maury Nicholson. superintendent of parks and piaygrounds, at the suggestion of the commissioners, has drawn up data on the kind of trees to plant on Arbor Day, and conditions under which they should be planted. Tho communication which he addressed to the commissioners was as follows:
 Tn order 10 secure permanent and de- sirable results from the planting of street trees there are a number of things to be considered. d) The conditions to which shade trees along streets and highways are subjected are very different from conditions surrounding trees grown in the forests. These conditions are in- variably less favorable to the successful growth and life of the trees therefore. characteristics and habits of trees must be considered when selecting them for this purpose.
 Selecting Street Trees
 Important points to be considered In the selection of street trees are as fol- lows:
 Hardness. that Is ability to thrive un- der the adverse conditions of city life. such as poor soil, abnormal amount of soot and dust. and unprotectedness from storms. Almost invariably the soil in which street trees must live Is poor, on account of the cutting down and filling of streets; also. the amount of exposed earth surface around the tree Is invariably lim- ceive q supply of moisture and air that It would in the forest, and In order to over come this the root system must be high ly developed in small space, in order to supply the tree with moisture and air through this limited space, and also to contend against the conditions of poor soil. Again, the head of tho tree, or the leaf system. through which the tree ab- sorbs the necessary elements from the atmosphere must contend with unfavor- able atmospheric conditions due to the presence of dust and soot.
 "Straightness and symmetry of growth are important combined with rounded or pyramid shaped head that adapts the tree to the use of the high way by traffic are essential, because the tree must protect the highway without interfering with It's use and being limited In the space that 1t can occupy. 1t is therefore important that the body of the tree should be straight and have it's limbs at such height as will clear all traffic and form the sym metrical shape within tho limited space that 1t must grow.
 Insect Attacks
 Immunity from attack by insects vary widely and this fact alone ex- cludes many otherwise very desirable trees from use on the streets. Some species of trees are almost immune from insect attacks. Others are so sus- ceptiblc to insect attacks and have sc many insect enemies that the planting of them encourages the spread of these insects to the detriment of other trees and, as an example of this. the Euro pean elm and the American elm, two ma gnifioen shade trees with many de- sirable qualities, are so susceptible to attacks of many insects that in some sections of the country their planting is practically abandoned.
 Abundance of shade is. Of course an essential for the street trees, this being one of the principal uses of the tree In this particular there Is also a wide variation in the characteris- tics of trees and this will therefore have weight in the selection for street planting.
 "Clcar1liness: Trees have character istie habits of cleanliness that are as marked as those of individuals. Some species, for instance. begin dropping leaves or twiss in the early part of the summer and continue through the fall, thus keeping the ground under meath the tree in more or less ,in- slightly condition. Other species drop seed. pods, fruit or burs In greater or less degree, causing inconvenience to foot traffic or unsightliness.
 i'I,ongevity, or length of life. is an Important consideration in selecting trees and one in which there is very wide variation. The city of Washing- ton, in which there are more properly planted end cared for trees than any other city in the United States, has eliminated some species of trees, prin- cipally because they have been found not to be long lived under city life conditions.
 Trees to Be Planted Here
 "There are some 800 different spe- cies of trees in the United States. but when all the characteristics necessary to overcome the unfavorable conditions of city life are sought in the selection of the trees there will remain only a comparatively few trees that will stand tho test. These will vary somewhat according to geographical location. The following are suggested az spe- cial that have been tried and proved successful in this locality. Accompany ing this .st is given a minimum dis-
  should be planted to secure the best re- suits: :,
 Norway maple, 70 feet; red maple, \ feet: pin oak, 3s feet: red oak, 45 feet, scarlet oak, 10 feet; willow oak, 40 feet water oak, 70 feet; sycamore (Plantanus Orientaiia), 45 feet; sycamore Celtic Occi- dentalis), 45 feet; hackberry. 3o feet gingko. 30 feet
 'sThe spacing of the tree is important not only as to the spacing on each side Of the street, but the opposite side of the street; the trees should be set opposie each other: also 1t Is very imporant that hole large enough to carry the root sys- tenn for two or three years should be ex- cavated. Some cities prescribe hole J feet deep, 3 feet wide and feet long. In any event the hole should be feet deep and not less than feet wide, if the park ing space will admit 1t and from to feet in length. In most instances all Of he soil should be removed and the best soil obtainable replaced. Be sure and Feep the weeds and grass off of the surface around the tree for a space of at least