(Ross Pier Wright, 1944).

Under western New York conditions, Slate (1930) reported that the
blooming period starts about March 20 to 25 at Geneva, and lasts about a
month. In central Virginia this may well be several weeks earlier. Slate
(1930) also reports that the flowers in bloom will withstand
considerable frost, and that even with temperatures of 16 deg.F. during the
blooming season, neither female nor male flowers, may be injured.
Nevertheless, with filberts coming into bloom in late February to early
March, they would be subjected to temperatures that might result in
injury especially to the catkins.

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 underst