Walnut Juglans regia (F)
ABOUT
The plant commonly known as the walnut tree is widely recognized for its distinctive features. It possesses a strong and sturdy trunk with deeply grooved bark, showcasing a rich array of shades from grey to dark brown. The tree has an expansive canopy that unfurls into a collection of broad, pinnate leaves, each radiating with multiple leaflets that are somewhat oval with pointed tips and serrated edges. These leaves are smooth, vibrant green on the top, and paler beneath. Come spring, the walnut tree blossoms with male and female flowers. The male flowers appear as slender, pendulous catkins which dangle gracefully, whereas the female flowers are smaller and typically occur in clusters. By autumn, the fertilized flowers give way to the fruit for which the tree is celebrated – the walnut. These fruits have a green, semi-fleshy husk which encases a hard, wrinkled shell, encasing the edible nut within. The walnut tree is notable for its majestic presence in the landscape, and the contrast of its leafy canopy against the sturdier wood provides an impressive spectacle throughout the seasons. Its appearance changes and shows a year-round evolution from the fresh green leaves of spring, the dense shade in summer, the yellowing foliage of autumn, and the bare branches in winter.
About this plant
NamesFamily
Juglandaceae.
Synonyms
English Walnut, Persian Walnut, Common Walnut, Carpathian Walnut, Royal Walnut, European Walnut.
Common names
Wallia regia (Lam.) Alef., Juglans duclouxiana Dode, Juglans fallax Dode, Juglans orientis Dode, Juglans regia var. sinensis C.DC., Juglans regia var. kamaonia (C.DC.) Rehder & H.Wilson, Juglans regia var. duclouxiana (Dode) Kitam., Juglans kamaonia C.DC., Juglans regia subsp. fallax (Dode) Popov, Juglans regia subsp. sinensis (C.DC.) W.E.Manning, Juglans regia var. orientis (Dode) W.E.Manning.
ToxicityTo humans
Juglans regia, commonly known as the English walnut, has edible nuts that are widely consumed and not poisonous to humans. However, other parts of the plant, such as the leaves, bark, and husks, contain juglone, which is a compound that can be toxic. Juglone is unlikely to cause harm in the small amounts that might be ingested accidentally, but consuming larger quantities could lead to stomach irritation or other gastrointestinal symptoms. The biggest risk to humans from the English walnut is the potential for allergic reactions in some individuals who may have an allergy to tree nuts. Symptoms of an allergic reaction can include hives, itching, swelling, difficulty breathing, and anaphylaxis, which is a medical emergency.
To pets
The English walnut, Juglans regia, contains juglone, which is a compound that can be toxic to some pets, especially dogs. While the nuts themselves are not typically considered toxic, they can cause gastrointestinal upset if eaten in large quantities. Moldy walnuts can contain toxins that are very dangerous to dogs, leading to symptoms such as vomiting, tremors, and seizures. Additionally, the juglone in the leaves, bark, and husks can also be harmful to pets, with horses being particularly sensitive to this compound. Ingesting plant parts containing juglone can lead to symptoms like laminitis in horses. Pet owners should be cautious and keep their animals away from English walnut trees to avoid any potential toxicity.
CharacteristicsLife cycle
Perennials
Foliage type
Deciduous
Color of leaves
Green
Height
49 feet [15 meters]
Spread
49 feet [15 meters]
Plant type
Tree
Hardiness zones
5
Native area
Eurasia
Benefits
General Benefits- Nutritional Value: Juglans regia, commonly known as the English walnut, is rich in healthy fats, proteins, fiber, antioxidants, vitamins, and minerals.
- Edible Products: The nuts are a popular food and can be eaten raw or used in cooking and baking, contributing to a variety of dishes.
- Wood Production: The wood of the English walnut tree is highly valued for its quality, color, and grain, making it a choice material for furniture, veneers, and gunstocks.
- Tannin Content: The tree's bark contains tannins, which have traditionally been used for tanning leather.
- Dye Production: Walnut husks can be used to produce a natural dye for fabric and hair.
- Habitat Support: The tree provides habitat and food for wildlife, including birds and squirrels.
- Landscape Aesthetics: The English walnut is an attractive tree with a broad crown, offering ornamental value in landscaping and gardening.
- Shade Provider: Its large canopy provides ample shade, making it a good choice for parks, gardens, and urban environments.
- Cultural Significance: The English walnut has historical importance and cultural value in many societies, often symbolizing intellect and wisdom.
Medical Properties- Antioxidant: Walnut (Juglans regia) contains bioactive components with antioxidant properties, which can help combat oxidative stress.
- Anti-inflammatory: Components within walnuts have been shown to have anti-inflammatory effects, potentially benefiting inflammatory conditions.
- Cardioprotective: Regular consumption of walnuts is associated with improved heart health and may help in reducing the risk of cardiovascular diseases.
- Antihyperlipidemic: Walnuts contain fatty acids that could aid in lowering blood lipid levels, thereby potentially reducing the risk of hyperlipidemia.
- Antidiabetic: There is some evidence to suggest that walnuts may help control blood sugar levels and could be beneficial for people with diabetes.
- Anticancer: Certain compounds found in walnuts might contribute to reducing the risk of certain types of cancer, although more research is needed.
- Cognitive Function: Walnuts contain omega-3 fatty acids and other nutrients that might be beneficial for maintaining cognitive function and brain health.
- Antiaging: Due to their antioxidant properties, walnuts may have antiaging effects on the cellular level.
- Weight Management: Some studies suggest that moderate walnut consumption could be a part of a weight management strategy due to their effect on satiety and metabolism.
- Gastrointestinal Health: The fiber content in walnuts helps in promoting digestive health and regular bowel movements.
Air-purifying QualitiesThis plant is not specifically known for air purifying qualities.
Other Uses- Juglans regia wood, also known as walnut, is highly valued for its fine grain, typically used in the crafting of furniture, gunstocks, and interior paneling.
- Walnut shells are ground and used as an abrasive in blast cleaning for the removal of paint and rust from hard surfaces.
- The shells can also be incorporated into exfoliating products like body scrubs due to their natural abrasive properties.
- Walnut oil, pressed from the nuts of the walnut tree, is used in art for cleaning brushes and as a paint thinner in oil painting.
- The husks of Juglans regia can be used to make a natural dye, which colors fabric and yarn to a rich brown hue.
- Walnut leaves can be infused to make a hair dye, which imparts a dark tint to the hair.
- The wood chips and sawdust from walnut timber are used in smoking foods to add a rich, nutty flavor.
- Walnut wood veneer is also used for making certain musical instruments due to its acoustic properties.
- In crafting, the empty walnut shells can be used to make miniatures or decorative ornaments, especially during Christmas.
- Walnut trees provide valuable habitat and food for wildlife; nuts that fall to the ground are an important food source for small mammals and birds.
Interesting Facts
Feng ShuiThe Walnut tree is not used in Feng Shui practice.
Zodiac Sign CompitabilityThe Walnut tree is not used in astrology practice.
Plant Symbolism- Wisdom: The common name of Juglans regia is the walnut tree. In various cultures, walnuts are associated with intellect due to their resemblance to the human brain, symbolizing wisdom and knowledge.
- Fertility: The walnut tree is often linked to fertility, with its seeds being symbolic of life and the continuation of generations.
- Prosperity: Walnut trees are also a symbol of prosperity and wealth because in some traditions, the nuts, being hard to crack, represent challenges that, when overcome, lead to success.
- Hidden truths and mysteries: The hard shell enclosing the nut symbolizes a strong exterior protecting something valuable, as such, walnuts can represent the pursuit of knowledge beneath the surface.
WaterThe English walnut tree should be watered deeply but infrequently, with the goal of encouraging deep root growth. Young trees benefit from watering once a week, and you should aim for about 1-2 gallons per watering session. Mature trees typically need less frequent watering, about once every two weeks or according to local rainfall and soil moisture conditions. Always ensure the soil dries out between waterings to prevent over-saturation and root rot. Over the course of a month, a mature English walnut may require around 8-16 gallons of water, depending on climate and soil conditions.
LightThe English walnut tree thrives in full sunlight but can tolerate some shade. Planting it in an area that receives at least 6 to 8 hours of direct sunlight daily is ideal for growth and nut production. The best spot for this tree is in a spacious landscape away from other large trees or structures that could cast significant shade on the canopy.
TemperatureThe English walnut tree prefers temperate climates, with the ideal temperature range for growing being between 85°F and 95°F. It can withstand winter temperatures as low as -10°F once fully established, but younger trees may need protection from hard frosts. The tree’s productivity and health might be compromised in areas where the temperature is consistently above 100°F or if exposed to prolonged freezes below 15°F.
PruningPruning the English walnut tree is essential for shaping, removing dead or diseased branches, and improving air circulation. Prune during the dormant season, preferably late winter or early spring before growth begins, to minimize sap flow from cuts. Thinning out the canopy every few years helps increase sunlight penetration and nut yield. Remove suckers growing from the base or along the trunk as they appear.
CleaningNot needed
SoilThe best soil mix for the walnut tree, or Juglans regia, should be deep, fertile, and well-draining with a slightly acidic to neutral pH of 6.0 to 7.5. A mix of loam, compost, and sand in equal parts can be ideal.
RepottingWalnut trees, being large and fast-growing, are not commonly repotted. Seedlings may be repotted annually, but mature walnut trees are best planted in a permanent outdoor location.
Humidity & MistingWalnut trees prefer moderate humidity levels but are adaptable to a wide range as they are hardy outdoor trees.
Suitable locationsIndoor
Growing a walnut tree indoors is not feasible due to its large size.
Outdoor
Plant in a sunny spot with well-draining soil and space to grow.
Hardiness zone
5-9 USDA
Life cycleJuglans regia, commonly known as the Persian walnut or English walnut, begins its life cycle as a seed, typically requiring a period of cold stratification to break dormancy. Upon germination in spring, the seedling emerges with a taproot and begins to develop leaves and a shoot system. As the tree grows, it undergoes a juvenile phase, which can last several years before it starts to produce flowers. Flowering occurs in late spring with separate male and female flowers on the same tree (monoecious); pollination is generally wind-mediated. Once pollinated, the female flowers develop into fruit, which are technically drupes with a green husk and a hard, woody shell enclosing the edible seed. The walnut tree matures and reaches full fruit-bearing capacity after several years, continuing to produce nuts annually.
PropogationPropogation time
Spring-Early Autumn
The most popular method for propagating the common walnut tree, Juglans regia, is through seed sowing. Seeds should ideally be sown in autumn, immediately after collection, as they require a period of cold stratification to break dormancy. The seeds are planted in a well-draining seedbed or directly into containers at a depth of about 2 inches (approximately 5 centimeters). The soil should be kept moist but not waterlogged to promote germination, which typically occurs in the spring. Walnut trees can also be grafted onto rootstocks, but this method is usually used by professional growers rather than home gardeners due to the skill required.
