In the book, "Nut Tree Culture in North American" by Richard Jaynes he
writes:
Ashworth mentions two Heartnut trees enduring -40° F. near Heuvelton New
York in 1934. They lost several years growth, dead wood was pruned out and
soon looked symmetrical again. Most of the named cultivars are considered
adaptable to zone 5. They tend to flush growth so early in spring that early
flowers and new foliage has been common in many years, even in zones six.
Based on what writing, zone 4 would almost certainly have problems.
Jerry
Re: [NAFEX] question about heartnuts..
, (continued)