I had cut off a few branches from the Jones hybrids when I received them and grafted these to wild hazels. This had been suggested by Robert Morris in his book, "Nut Growing," as an interesting experiment which might prove to be practical. It did not prove to be so for me for although the grafting itself was successful I found it tiresome to prune, repeatedly, the suckers which constantly spring up during the growing period and which are detrimental to grafts. Although they lived for five years, these grafts suffered a great deal of winter-injury and they never bore nuts. The one which lived for the longest time became quite large and overgrew the stock of the wild hazel. This same plant produced both staminate and pistillate blossoms very abundantly for several seasons but it did not set any nuts in spite of the many wild hazels growing nearby which gave it access to pollen. It is now known that this hybrid is self-sterile and must have pollinators of the right variety in order to bear.
My next work with members of the genus Corylus was discouraging. In April 1929, I bought one hundred hazel and filbert plants from Conrad Vollertsen of Rochester, New York, which included specimens of the Rush hazel and of the following varieties of filberts:
Italian Red
Merribrook
Kentish Cob
Early Globe
Zellernuts
White Lambert
Althaldensleben
Medium Long
Bony Bush
Large Globe
Minnas Zeller
Marveille de Bollwyller
Although many of these filberts bore nuts the first year they were planted, within two years they were all completely winter-killed.
In 1932, I received ten filbert bushes from J. U. Gellatly of West Bank, British Columbia. These consisted of several varieties of Glover's best introductions and some Pearson seedlings. I planted them on the south side of a high stone wall, a favorable location for semi-hardy plants. They appeared to be thrifty and only slightly winter-killed during the first two years but by 1939, all but two of the bushes had died or were dying. Although as nut-bearing plants they have been of little value to me, their pollen has been of great service.
I found an unusually fine wild hazel growing in the woods on my farm and in 1934, I began an experiment in hybridizing it. I crossed the pistillate flowers of the native hazel with pollen from a Gellatly filbert and obtained four hybrid plants, which I have called hazilberts. In the spring of 1940, three of these hybrids had pistillate flowers but no staminate blooms. As I was very eager to see what the new crosses would be like, I fertilized the blossoms with a gunshot mixture of pollen from other plants such as the Winkler hazel, the European filbert and the Jones hybrid hazel. Certain difficulties arose in making these hybrids, mainly due to the curiosity of the squirrels who liked to rip open the sacks covering the blossoms which were being treated. Deer mice, too, I found, have a habit of climbing the stems of hazel bushes and gnawing at the nuts long before they are mature enough to use for seed. Later I learned to protect hybrid nuts by lacing flat pieces of window screening over each branch, thus making a mouse-proof enclosure. Even after gathering the nuts I discovered that precautions were necessary to prevent rodents from reaching them. The best way I found to do this is to plant nuts in cages of galvanized hardware cloth of 2 by 2 mesh, countersunk in the ground one foot and covered completely by a frame of the same material reinforced with boards and laths.
The most interesting hazilbert that has developed bears nuts of outstanding size, typically filberts in every detail of appearance, although the plant itself looks more like a hazel, being bushy and having many suckers. After more testing, this hybrid may prove to be a definite asset to nursery culture in our cold northern climate, fulfilling as it does, all the requirements for such a plant. The second hazilbert resembles the first closely except that its nuts, which are also large, are shaped like those of Corylus Americana. The third hazilbert has smaller nuts but its shell is much thinner than that of either of the others.
In reference to the hazilberts, I am reminded of certain correspondence I once had with J. F. Jones. He had sent me samples of the Rush hazel and although I was impressed by them, I mentioned in replying to him that we had wild hazels growing in our pasture which were as large or larger than the Rush hazelnuts. I admitted that ours were usually very much infested with the hazel weevil. Mr. Jones was immediately interested in wild hazels of such size and asked me to send him samples of them. He wrote that he had never seen wild hazels with worms in them and would like to learn more about them. I sent him both good and wormy nuts from the wild hazel bush to which I had referred. He was so impressed by them that he wished me to dig up the plant and ship it to him, writing that he wished to cross it with filbert pollen as an experiment. I sent it as he asked but before he was able to make the cross he intended, his death occurred. Several years later, his daughter Mildred wrote to me about this hazel bush, asking if I knew where her father had planted it. Unfortunately I could give her no information about where, among his many experiments, this bush would be, so that the plant was lost sight of for a time. Later Miss Jones sent me nuts from a bush which she thought might be the one I had sent. I was glad to be able to identify those nuts as being, indeed, from that bush.
In the spring of 1939, I crossed the Winkler hazel with filbert pollen; the European hazel with Winkler pollen; the Gellatly filbert with Jones hybrid pollen. These crosses produced many plants which will be new and interesting types to watch and build from. I have already made certain discoveries about them. By close examination of about forty plants, I have been able to determine that at least five are definitely hybrids by the color, shape and size of their buds. This is a very strong indication of hybridity with wild hazel or Winkler. On one of these plants, about one-foot high, I found staminate bloom which I consider unusual after only two seasons' growth.
During the fall of 1941, I became interested in a phenomenon of fruit determination previous to actual fructification of the plant by detailed examinations of its buds. I noticed, for instance, that large buds generally meant that the plant would produce large nuts and small buds indicated small nuts to come. The color of the buds, whether they were green, bronze green or reddish brown, could be fairly well depended upon to indicate their hybridity in many cases. These tests were not wholly reliable but the percentage of indication was so high that I was tempted to make predictions.