I cannot conclude this chapter without mentioning certain observations I have made regarding hardiness, which, although they require more specific study, I wish to describe as a suggestion for further experimentation by either amateur or professional horticulturists.  My theory is that a determination of the hardiness factor of an English walnut tree can be made according to the color of its bark.  I have seen that a tree having thin bark which remains bright green late into the fall is very likely to be of a tender variety.  Conversely, among these Carpathian walnuts, I have found that varieties whose bark becomes tan or brown early in autumn show much more hardiness than those whose bark remains green.  One variety, Wolhynie, whose bark is chocolate brown, is very resistant to winter injury.  Another, whose green bark is heavily dotted with lenticels, shows itself hardier than those having none or only a trace of them.  In testing almonds, I have found that trees whose bark turns red early in the fall are definitely more hardy than those whose bark remains green or tan.  In observing apricots, I have learned that young twigs with red bark are more resistant to cold than those with brown.  Of course, these findings cannot be considered as facts until further studies have been made.  I hope that others will find the idea of investigating this more-than-possibility as interesting as I do.

As the years increased, however, the growth of the seedling walnuts decreased and some having made a nice tree-like form, with a trunk of approximately an inch in diameter, within a succession of years were reduced in size through the combination of winter injury and attacks by the butternut curculio as well as a bacterial blight until by 1952 only a fraction of the 12,000 seedlings remained, certainly less than 1,000.  All of the originally grafted specimens are dead with the exception of one variety which has been kept alive by constantly re-grafting it on black walnut.  We have not named this variety as yet, although it has borne both staminate and pistillate bloom, it has never borne any ripe nuts.  Some of the seedlings, however, still show persistent traits of hardiness and of insect resistance and we still have hopes that after 15 years these trees will yet overcome the adversities of this uncongenial climate for this species.

Chapter 10

OTHER TREES

Heartnut

The heartnut is a sport of the Japanese walnut (Juglans sieboldiana).  Since its nut is heart-shaped, it has the name of “cordiformis” added to its species name.  There are many of these sports, some of which have been propagated under the varietal names of Faust, Lancaster, Fodermaier, Wright, Walters, Canoka, Okay and Gellatly.