English Walnut

Juglans regia

Juglandaceae · broadleaf · introduced

Quick Facts

Height

40–60 ft

Spread

65 ft

Growth Rate

Fast

Light

Full Sun

Soil

Moist

Water

High

Hardiness

Zone Zones 6b–9b

Bloom Time

May to June

Origin

southern Europe to the Himalayas and China

Phenological Calendar

Stage	Typical Window	What to Look For
Bud break BBCH 07	Feb 15-Mar 15	Buds swelling and beginning to open; first green tissue visible
Leaf emergence BBCH 11	Mar 1-Apr 1	First leaves fully unfurled on new growth
Bloom start BBCH 61	Apr 1-Apr 30	First open flowers visible; flowers white
Bloom end / petal fall BBCH 69	Apr 15-May 15	Last petals falling; flower structures fading
Fruit/seed development BBCH 71	Jun 1-Aug 31	Fruit or seed structures forming; fruit color: brown
Fruit/seed maturity BBCH 85	Sep 1-Nov 30	Fruit fully colored and ripened; seed dispersal may begin
Leaf drop BBCH 93	Oct 15-Nov 30	Leaves yellowing and dropping; no significant fall color display
Dormancy BBCH 97	Nov 15-Feb 28	Leafless; no active growth; dormant buds set

Diseases (9)

Various species including Colletotrichum acutatum, C Anthracnose

Black Walnut Toxicity

Rhizobium radiobacter (formerly Agrobacterium tumefaciens) Crown Gall

Downy Leaf Spot

Mosses and Lichens

Phytophthora spp. (P Phytophthora Root Rot

Geosmithia morbida (vectored by Pityophthorus juglandis) Thousand Cankers Disease

Pests (8)

Anthracnose Blotch

European Fruit Lecanium

Aceria erinea Walnut Blister Mite

Walnut Husk Fly

Walnut Twig Beetle

Nematode, Root-lesion