Some of the more hardy varieties as reported by Slate (1930) include the following: (a) White Lambert (not of value) (C. maxima); (b) Red Lambert (C. maxima); (c) Cosford; (d) Purple Aveline (C. avellana); and (e) Early Globe (of little value).
Some of the varieties upon which both the staminate and pistillate flowers tend to bloom relatively late are (a) Althaldensleber, (b) Kentish Cob, (c) Red Aveline, (d) Purple Aveline, and (e) Bolwiller. Late blooming, however, does not necessarily insure escaping injury from low spring temperatures. The Cosford, Italian Red, and Medium Long are considered by Slate as good for New York. The Bixby and Buchanan are the result of crossing C. americana x C. avellana, and appear to be of promise for home plantings in the East. Mr. H. F. Stoke is growing the Italian Red and Du Chilly (Kentish Cob) with Daviana for pollination purposes in the Roanoke area.
CROSS-POLLINATION. A fourth limitation is the fact that varieties are nearly entirely if not fully dependent upon cross-pollinization by other inter-fertile varieties that bloom at about the same time in order to insure a set of nuts. This limitation may be overcome by the proper planning of hardy varieties are inter-fertile. Colby (1944) has reported that the Winkler variety is self-fertile.
SUCKERS. A sixth limitation is the tendency of the C. avellana or C. maxima to sprout about the base and the labor and expense of keeping these sprouts pruned out. It is possible that this factor may be overcome by using Turkish hazel (C. colurna L.) as an understock and grafting or budding thereon the varieties that sprout when on their own roots. The Turkish hazel does not sprout as badly as the two other species.
Note by Editor: An Oregon nursery, which formerly propagated European filberts on the Turkish understock, now has abandoned its use. The grafted filbert tops did not seem to survive and bear as consistently as those on their own roots, after a period of several years in orchards.
PLANTING IN VIRGINIA. In a letter dated May 17, 1948, addressed to R. C. Moore, Assistant Horticulturist, V.P.I., H. J. Pettit, Assistant Secretary of the Planters Peanut Company, Suffolk, Virginia, reported that some years ago they planted several thousand trees of filberts, which they obtained from the states of New York and Oregon. From their experience it appears that late spring frosts destroyed the flower parts, which developed early, with the result that the yields were too low to be profitable. Hence, the filberts were removed and the land otherwise utilized. Mr. H. F. Stoke, however, in the Roanoke area has not found lack of hardiness as serious as the problems of diseases and insects of filberts.
An important nursery in Maryland has provided information to the effect that during this past 1947-48 season it sold for planting in Virginia a total of 34 filbert plants in lots of from one to ten. Its 1947-48 catalogue lists varieties of filberts for sale as follows: Barcelona, Daviana, Du Chilly, and American hazel.
Dr. H. L. Crane, Principal Horticulturist of the USDA, writes in a letter dated July 27, 1948, that he knows of no substantial plantings being made anywhere in Virginia. He has observed a few bushes or trees scattered about the homesteads, particularly in the northern or more mountainous part of the state. In most cases the performance of these filberts has not been entirely satisfactory because of leaf scorch during the summer, due apparently to high temperatures or unfavorable moisture conditions or to the winter killing of the catkins, or in some cases winter injury of the shoots. The largest plantings in Virginia that have yet come to the attention of the V.P.I. Department of Horticulture are those of Mr. Stoke in the Roanoke area.
Dr. Crane has observed the planting of a few bushes of the American hazelnut in Virginia. Their performance has been somewhat better than has been that of the European filbert, especially as to hardiness, and these American hazelnuts have borne more satisfactory crops of nuts than have the European filberts. The nuts produced by the native varieties, however, are small in size, thick shelled, and the kernels are small and lack quality. Observations by Dr. Crane, which have been made in the State of Virginia, lead him to believe that with the material that is at present available from nurserymen, there is not much hope of successful commercial filbert culture in the State of Virginia. When, however, seedlings 1667 and 2336 may become available, two varieties that are hardy and productive of fairly high quality nuts may provide material for home plantings or for local markets.
Ornamental Value. The filbert, however, also has possible value for ornamental plantings with its attractive foliage, or as a hedge, as well as for nut production, providing the home owner will control insects and diseases and maintain favorable growing conditions for our best known varieties.