In an “on” year—a year of heavy production—this black walnut tree of the 
variety Ohio yielded 16% bushels of nuts. 
do not come true from seed; they are 
propagated by grafting scions (twigs) 
from trees of the desired varieties onto 
the main stems of 2- or 3-year-old na- 
tive seedlings. The scions develop into 
tree crowns that bear nuts of their own 
varieties. 
Little information is available to in- 
dicate the best varieties for different 
localities. Local nurseries usually sell 
varieties that are best suited to their 
own localities. 
For the greatest possible nut produc- 
tion, plant trees of two or more varie- 
ties. Usually, pistillate (female) flowers 
produce nuts after being pollinated by 
staminate flowers of the same tree. In 
very early or very late springs, the pis- 
tillate flowers may not be ready when 
The tree was 30 years old. 
the pollen is shed. Different varieties 
have overlapping _ pollen-receptivity 
periods and can pollinate each other. 
All black walnut trees tend to bear 
heavy nut crops every second year and 
light ones in between. Exact cultural 
practices to offset alternate-year bear- 
ing have not been developed. 
PLANTING SITES 
Black walnut trees grow best in rich, 
loose soils of limestone origin that are 
at least 4 feet deep. Since the trees 
develop deep taproots, the suboil 
should be easily penetrated by roots. 
The soil must be well drained and 
not strongly acid. The trees will not 
grow well on bottomland where the soil 
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