I cultivated the Douglas fir, white, Norway, and Colorado blue varieties of spruce.  Besides these, I planted balsam fir, red cedar, Juniperus Virginiana, and white cedar, Arborvitae.  Practically all of these trees are still growing and many of them bear seed.

I wish to describe the limber pine, Pinus flexilis, for it is not only a good grower and quite hardy but it is also a very ornamental nut pine which grows to be a broad, stout-trunked tree 40 to 75 feet high.  The young bark is pale grey or silver; the old bark is very dark, in square plates.  The wood itself is light, soft and close-grained, having a color that varies from yellow to red.  The needles, which are found in clusters of five, are slender, 1-1/2 to 3 inches long, and are dark green.  They are shed during the fifth or sixth year.  The buds of the tree are found bunched at the branch tips and are scaly and pointed.  The limber pine has flowers like those of the white pine, except that they are rose-colored.  Although the fruit is described as annual, I have found that, in this locality, it takes about fifteen months from the time the blossoms appear for it to reach maturity.  That is, the fruit requires two seasons for growth, maturing its seeds the second September.  The cones of the limber pine, which vary from three to seven inches in length, are purple, having thick rounded scales and being abruptly peaked at the apex.  The seeds are wingless or have only very narrow wings around them.

With the idea of getting practical results sooner, since nut trees mature slowly, I interplanted my nut trees with varieties of apple, plum and cherry.  Doing so also served to economize on ground, since ultimately nut trees require a great deal of space for best growth.  Walnut trees, for example, should be set 40 to 60 feet apart in each direction.

[Illustration:  Pinus Flexilus nut seeds, Natural Size]

I learned a variety of facts during these first years of trial and error.  I discovered, for instance, that iron fence posts rust away in an acid soil; that one must use cedar or oak.  Conversely, in alkaline soil, iron will last indefinitely, but that the nitrogenous bacteria will quickly rot wooden posts.  I found that the secret of growing hickories successfully lies in giving them plenty of room, with no forest trees around to cut off their supply of sunlight and air.  I learned that it is impractical to graft a large forest tree of butternut or hickory.  Incidental to that, I learned that a branch of a butternut tree which looks large enough to support a man’s weight near the trunk, will not do so when the branch is green and alive, but that a dead branch of similar size will.  Contrariwise, even a small green limb of a bitternut-hickory will bear my weight, but an old limb, though several inches thick, becomes so brittle after it is dead for several years that it will break under slight pressure.  Fortunately, falls from trees do not usually result in serious injuries but I did acquire quite a few bruises learning these distinctions.