English Walnut: A Productive Shade Tree for Large Landscapes
If you’ve ever cracked open a fresh walnut, chances are you were enjoying the fruit of Juglans regia, commonly known as the English walnut. This substantial tree has found its way into North American landscapes, offering both shade and a harvest of delicious nuts. But before you plant one in your yard, let’s explore whether this non-native species is right for your garden.
What is the English Walnut?
The English walnut is a large, perennial tree that can reach impressive heights of up to 60 feet at maturity. Despite its common name, this species isn’t actually from England—it’s originally native to regions stretching from the Balkans through the Himalayas to southwest China. The English moniker comes from the English merchant marines who traded these nuts centuries ago.
This fast-growing tree develops a single trunk and creates a broad, rounded canopy. Its large compound leaves, each containing 5-9 leaflets, provide dense summer shade that becomes porous in winter when the leaves drop. The tree is also known as an allelopath, meaning it releases chemicals that can inhibit the growth of nearby plants—something to keep in mind when planning your garden layout.
Where Does English Walnut Grow?
As a non-native species, the English walnut has established itself in several North American regions, including California, Ontario, Idaho, Michigan, New York, and Washington. It reproduces spontaneously in the wild and tends to persist without human intervention in these areas.
Should You Plant English Walnut in Your Garden?
The decision to plant an English walnut depends largely on your space and goals. Here’s what to consider:
The Case for English Walnut
- Dual purpose: Provides both shade and edible nuts
- Fast growth: Can reach 25 feet in just 20 years
- Hardy: Tolerates temperatures down to -8°F (USDA zones 4-9)
- Commercial availability: Readily available from nurseries
- Productive: High seed/nut abundance when mature
The Case Against English Walnut
- Non-native status: Doesn’t support native ecosystems as effectively as indigenous species
- Limited wildlife value: Provides only 2-5% of terrestrial birds’ diet and sparse cover
- Space requirements: Needs significant room to grow properly
- Allelopathic effects: Can inhibit growth of nearby plants
- Climate specific: Requires 190+ frost-free days and consistent moisture
Native Alternatives to Consider
Before choosing English walnut, consider these native nut-producing trees that better support local wildlife:
- Black walnut (Juglans nigra): A native cousin with similar nuts but greater ecological value
- American chestnut (Castanea dentata): Blight-resistant varieties are becoming available
- Native hickories (Carya species): Excellent for wildlife and produce edible nuts
- American hazelnut (Corylus americana): Smaller stature but excellent for wildlife
Growing Conditions and Care
If you decide to grow English walnut, here’s what it needs to thrive:
Soil and Site Requirements
- Soil type: Prefers fine to medium-textured, well-draining soils
- pH range: 6.0 to 7.5 (slightly acidic to neutral)
- Sun exposure: Full sun (shade intolerant)
- Space: Allow 100-800 trees per acre spacing
- Root depth: Needs at least 40 inches of soil depth
Climate Needs
- Hardiness: USDA zones 4-9
- Precipitation: 28-45 inches annually
- Frost-free period: Minimum 190 days
- Drought tolerance: Moderate, but prefers consistent moisture
Planting and Establishment
English walnuts can be planted as bare root trees or container plants, ideally in spring. Seeds require cold stratification before planting. The tree has high seedling vigor once established, but growth rate slows in spreading since it doesn’t reproduce vegetatively.
Keep in mind that young trees have low fire tolerance, so avoid planting in fire-prone areas. The species also has poor hedge tolerance, making it unsuitable for formal pruning or small spaces.
Pollination and Fruit Production
English walnut trees are monoecious, meaning they have both male and female flowers on the same tree. They bloom in mid-spring with inconspicuous white flowers. While wind-pollinated, they offer minimal benefits to pollinators like bees and butterflies. Fruit production begins in summer and continues through fall, with nuts persisting on the tree until harvest.
The Bottom Line
English walnut can be a valuable addition to large properties where space isn’t limited and nut production is desired. However, as gardeners increasingly focus on supporting native ecosystems, consider whether a native alternative might better serve both your needs and local wildlife. If you do choose English walnut, plant it thoughtfully, giving it plenty of room and understanding its allelopathic nature.
Remember, the best garden is one that balances your personal goals with ecological responsibility. Whether you choose English walnut or a native alternative, you’ll be creating valuable habitat and food sources for years to come.
