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Library / Plants / Japanese Walnut

Japanese Walnut

Juglans ailantifolia

Juglandaceae · broadleaf deciduous tree · introduced

Last updated May 10, 2026

Quick Facts

Height
40–65 ft
Light
Full Sun
Hardiness
Zone Zones 5a–8b
Origin
Japan; introduced in 1860 A sport of the Japanese walnut,
Watch for this season
Phytophthora Root RotModerate

Growing Season Stress Expression

Crown GallMonitor

Dormant in Soil

Diseases: Regionally Documented (10)

Geosmithia morbida (vectored by Pityophthorus juglandis) Thousand Cankers Disease Xanthomonas arboricola pv. juglandis Walnut Blight Blackline virus Blackline Ophiognomonia leptostyla (syn. Gnomonia leptostyla) Anthracnose Blotch Black Walnut Toxicity Rhizobium radiobacter (formerly Agrobacterium tumefaciens) Crown Gall Pseudomicrostroma juglandis (syn. Microstroma juglandis) Downy Leaf Spot Mosses and Lichens Phytophthora spp. (P Phytophthora Root Rot Pratylenchus penetrans (primary) and P Nematode, Root-lesion

Pests: Regionally Documented (6)

Pityophthorus juglandis Walnut Twig Beetle Rhagoletis completa Walnut Husk Fly Aceria erinea Walnut Blister Mite Chromaphis juglandicola Walnut Aphid Parthenolecanium corni European Fruit Lecanium Hyphantria cunea Fall webworm
Data Maturity
Baseline Structured Expert-reviewed Field-verified
Structured Multiple sources. Expert review underway.

Also Known As

  • Heartnut

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