Observations on Hardiness of the Carpathian Walnuts at Poughkeepsie, New York

STEPHEN BERNATH

In our section we have very good Persian walnut varieties of Carpathian and other European sources. I have planted some of all strains and varieties. My place faces northwest on a good elevation. My experience with trees there is that we have no winter injury. We can grow trees there that cannot be grown on some place which is situated low, and therefore does not have enough air circulation. Damage is done after heavy frosts when the sun comes out suddenly. That is what damages the trees—not the cold.

If you take trees and put them in a temperature of 35 to 40 degrees below zero and bring them out to thaw gradually no harm is done. Most people buy trees and plant them in low places; that is the error. We have planted trees where the wind is very heavy throughout the winter and in the spring I found that these trees stood up wonderfully well; whereas, we have European walnut trees with a trunk diameter of about 12 to 14 inches that in one year froze two to six feet—about three to four years growth. If you plant your trees on a fairly good elevation you can be assured of a good nut crop. In planting nut trees I do not know what kind of fertilizer you use, but I always use well decayed cow manure and put a little right around the root system. I never use fresh manure and never use poultry, sheep, or horse manure. They are bad for trees as they are very high in ammonia and this does damage to the trees.

Discussion after Graham, Smith, and Bernath Persian walnut papers.

Corsan: "Is using lime a good idea? I always use a lot of wood ashes."

Stoke: "Use ground agricultural limestone. Burned lime may cause injury."

J. R. Smith: "Barnyard manure is the best."

Stoke: "With the Carpathian walnuts there is no uniformity in winter injury. I have had the Crath variety kill back to two inch wood. Most others have never shown winter injury."

Corsan: "When is it practical to take mulch away?"

MacDaniels: "If you take mulch away too late you will get more injury than if you don't take it away at all."

Member: "Why does my young walnut tree not bear?"

Bernath: "English walnut trees may produce pistillate blooms for a number of years before they produce pollen so that if you have only one tree it may be due to lack of pollination."

Member: "With English walnut is more than one tree necessary for pollination? The male blossom appears a week or 10 days before the female."

Crane: "Persian walnuts should be used to pollinate Persian walnuts—do not depend on black walnuts. In growing Persian walnuts it is best to have trees of two or more varieties in a planting so as to provide cross pollination."

Stoke: "Persian walnuts may not pollinate black walnut, but black walnut has pollinated the Persian walnut in known instances."

MacDaniels: "Control or uncontrol of pollination is very complex."

Crane: "We find that we can not readily produce Persian x Eastern black hybrids under conditions of controlled pollination. We have found a number of natural hybrid trees but they bear very few nuts."