jack pine --Pinus banksiana (very hardy)
limber pine --Pinus flexilis
(semi-hardy, a fine nut pine).

Many of the limber pines came into bearing about fifteen years after the
seed was planted. At that age they varied in height from three to
fifteen feet. One little three-foot tree had several large cones full of
seed. Each tree varied in the quality and size of its seeds. Although it
might be possible to graft the best varieties on young seedling stocks,
in all the hundreds of grafts I have made on pine, I have been
successful only once. I doubt that such a thing would ever be practical
from a commercial standpoint unless some new method were discovered by
which a larger percentage of successful grafts could be realized.

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, s