Although we do not know what determines hardiness, we may still go ahead with our experimental work. We do not really know what electricity is, but inventors in that line have enough of a theory on this subject so that they are able to work very successfully with this gigantic force of nature. We know there is a difference in hardiness between the red cedar of Tennessee and the red cedar of Minnesota, and that it is safest for us to plant the tree as it is found at the north. The same applies to many other trees that are found native over a wide area. At Moscow, Russia, the box elder as first imported was from St. Louis, and it winter-killed. Afterwards they got the box elder from Manitoba, and it proved perfectly hardy. Although botanically both are the same, yet there is a difference in hardiness.
My way of securing hardiness is to work with plants that are already hardy. I like to work with native plums in my plant breeding experiments because there need be no concern about their hardiness. We know they are hardy, or they would not be here after thousands of years of natural selection in this climate.
The other way of obtaining hardiness is by crossing a tender variety with a hardy one. When we cross the native plum with the Japanese plum, we obtain seedlings that combine in a fair measure the hardiness of the native plum with the size and quality of the Japanese plum.
In many states of the Union the question of varieties for commercial orchards has been to a large degree settled. There is always room for a new apple, but for commercial purposes the varieties already in cultivation are sufficiently satisfactory as to size, color and quality as well as in keeping and shipping capacity. So the main effort in their horticultural societies is along other lines, such questions as marketing, packing, spraying, insects, fungi and orchard management. But in this region the winter apple question is still a vital one.
Some promising winter apples have appeared recently, and it remains to be seen whether they will stand up under the next test winter. They are certainly satisfactory in size, color, quality and keeping capacity.
The greatest question now presents itself in planting apple seed. What variety shall I choose? Some pedigrees may be like a blind alley, they will lead us nowhere. The commercial apples of the East and of the Pacific Coast are the survivors of millions of apple seedlings raised by immigrants from Western Europe during the past three centuries. They survived because they were the best. From time to time very good varieties are super-ceded by new ones that appear. From the ashes of millions of seedlings will arise, Phoenix-like, the creations that will dominate our future prairie pomology. Here in the Northwest thousands of farmers have already determined to a considerable extent what we may expect from planting the seed of certain standard varieties.