Growing black walnut
nut
WINTER CHILL NEEDED
~700–1500 hrs
POLLINATION
Partly self-fertile — crops much better with a partner
Pollination
As with English walnut, a second tree improves nut set.
Growing it
Zones 4-9. Native, massive, and the strongest juglone producer - keep it well away from a vegetable garden. Prized, hard-shelled, richly flavoured nuts.
Will you get enough chill?
Black Walnut needs roughly 700–1500 hours between 32 and 45 °F over winter to break dormancy evenly. Check your area with the chill hours calculator. Low-chill breeding has pushed many varieties well below the figure here, so read the plant tag.
Chill and pollination are given at the fruit-type level; specific cultivars can differ. Values are typical ranges for home-garden planning.