English walnut Juglans regia
English walnut (Juglans regia) is a deciduous perennial tree in the Juglandaceae family, native to Balkans to the Himalaya and China. It grows 10–18 m (33–59 ft) tall and 8–15 m (26–49 ft) wide, wants full sun and moderate water, and is hardy to about -26 °C (-15 °F). Space plants about 12 m (39 ft) apart.
Plan English walnut in your garden →
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English walnut at a glance
| Type | Perennial tree, deciduous |
|---|---|
| Family | Juglandaceae |
| Mature height | 10–18 m (33–59 ft) |
| Mature spread | 8–15 m (26–49 ft) |
| Spacing | 12 m (39 ft) centre to centre |
| Sun | Full sun, at least 7 h of direct sun a day |
| Water | Moderate; drought tolerance moderate, waterlogging tolerance none |
| Soil pH | 6–7.5 |
| Cold hardiness | About -26 °C (-15 °F) once established (roughly USDA zone 5) |
| Heat stress | Likely above about 38 °C (100 °F) |
| Flowering | from about May for 2–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | None |
| Edible | Yes: nuts |
| Native to | Balkans to the Himalaya and China |
| Common in gardens of | 🇫🇷 France, 🇨🇳 China, 🇺🇸 United States, 🇹🇷 Turkey, 🇮🇷 Iran |
Is English walnut toxic?
- People: not known to be toxic
- Cats: not well documented
- Dogs: mildly toxic
- Parts: moldy nuts, husks
Mouldy nuts and hulls can carry tremorgenic mycotoxins that cause tremors and seizures in dogs.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with English walnut
No well-documented helpful pairing. Group it with plants that like full sun and moderate water.
Keep apart or take care
- caution With Dwarf apple tree: English walnut also produces juglone, usually in lower amounts than black walnut, so sensitive plants such as apple may do poorly under or near its canopy. Evidence C
Shared pests and diseases
- Verticillium wilt: Verticillium lives in soil for years; hosts planted together or in sequence build it up. Evidence B
Questions about English walnut
- How far apart should I plant English walnut?
- About 12 m (39 ft) apart, centre to centre. A mature plant spreads 8–15 m (26–49 ft).
- Does English walnut need full sun?
- Full sun: at least 7 hours of direct sun a day.
- How much water does English walnut need?
- Moderate water. Drought tolerance is moderate and waterlogging tolerance none.
- How cold-hardy is English walnut?
- It tolerates about -26 °C (-15 °F) once established, roughly USDA zone 5.
- When does English walnut flower?
- From about May for 2–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is English walnut poisonous to cats and dogs?
- For cats it is not well documented; for dogs mildly toxic; for people not known to be toxic. Mouldy nuts and hulls can carry tremorgenic mycotoxins that cause tremors and seizures in dogs.
- What grows well with English walnut?
- There is no well-documented companion pairing for English walnut. Group it with plants that like the same sun (full sun) and water (moderate).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- RHS Plant Finder, Royal Horticultural Society
- University extension gardening guides (general), Various land-grant university extensions
- Fruit & Nut Research and Information Center: chilling requirements by species and cultivar, University of California, Davis
- Black walnut toxicity to plants (sensitive and tolerant lists), University of Wisconsin-Madison Extension Horticulture
- FAO Irrigation and Drainage Paper 56 — Crop Evapotranspiration, FAO
Notes and assumptions
- Male and female flowers open at different times on many cultivars (dichogamy), so pairs or self-fertile cultivars improve nut set; chill about 400-1500 hours by cultivar.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Black walnut Juglans nigra
- Pecan Carya illinoinensis
- Dwarf mountain pine Pinus mugo
- Japanese maple Acer palmatum
- English yew Taxus baccata
- Serviceberry Amelanchier canadensis
- Japanese flowering cherry Prunus serrulata
- Saucer magnolia Magnolia x soulangeana