Walnut trees are any species of tree in the plant genus Juglans, the type genus of the family Juglandaceae, the seeds of which are referred to as walnuts. Many people also consider walnut trees attractive because of their deciduous leaves and large 50- to 75-foot spread. Walnut trees have long compound leaves with 5 to 23 short-stalked leaflets. The male and female reproductive organs are borne in different petal-less flower clusters, known as catkins, on the same tree. The twigs characteristically contain a many-chambered pith. The fruit is not a true botanical nut: it is a drupe with the edible seed (commonly called a nut) enclosed in a shell within a thick husk.
Walnut kernels can be eaten fresh or processed for use in baked goods and confectionery. The timber of the tree is a highly valued as a wood for furniture making in Europe. Kernels may also be used as an animal feed or used to extract oil which was once a popular thinner for oil based paints. Here are some of the common walnut tree varieties you need to know:
- Black Walnut (Juglans nigra)
- Arizona Black Walnut (Juglans major)
- Northern California Black Walnut (Juglans hindsii)
- Southern California Black Walnut (Juglans californica)
- Butternut Walnut (Juglans cinera)
- Andean Walnut (Juglans neotropica)
- English Walnut (Juglans regia)
- Manchurian Walnut (Juglans mandshurica)
- Japanese Walnut (Juglans ailantifolia)
- Texas Walnut (Juglans microcarpa)
- Chandler Walnut
- Franquette Walnut (Juglans regia ‘Franquette‘)
- Hartley Walnut
- Fernor Walnut Tree
- Apollo Walnut Tree
- Pedro Walnut Tree
- Lara Walnut Tree
Black walnut also called eastern black walnut A black walnut tree usually is between 65 and 100 feet tall and has a trunk about 2 to 3 feet in diameter, with deeply furrowed dark brown or grayish black bark. Black walnut grows slowly, maturing on good soils in about 150 years; it may have a life span of more than 250 years. The dark fine-grained wood of black walnuts is used for furniture, paneling, and gunstocks. They prefer areas where there’s some sun and shade, like canyons or along established washes and stream banks.
Arizona walnut trees have light brown or gray bark with deep crevasses and can grow up to 48 feet tall. They shed their leaves every year and are considered “round-crowned,” meaning the tree, when flushed with greenery, forms the shape of a circle. The walnut boasts green leaf stalks that divide into smaller leaflets, known as a “pinnately compound.” Given its name, however, is it only native to Arizona, Texas and parts of Mexico.
Northern California Walnut
Northern California walnut is a deciduous tree to 50 ft that is native in scattered spots throughout California. The bark is dark and rough and has a noticeable smell when abraded. The nut is smooth and hard and is embedded in a thick green husk that will stain the fingers.
Southern California Black Walnut
The Southern California black walnut is a large deciduous shrub or tree that commonly grows with many trunks. Leaves are deep green and pinnately and over time it can this tree can reach heights of 20-35 feet. Flowering occurs in early spring; small round walnuts mature by late fall. The nuts are of little commercial value, but are important to wildlife.
Butternut is a fast growing tree closely related to and resembling Eastern black walnut (juglans nigra). The bark is more gray and less fissured than the Eastern black walnut, and the nuts are more oval and less rounded than the fruit of the black walnut.The two trees can often be found growing together in rich flood plains as well as on the thinner soil of the hillsides. Butternut tree forms a broadly rounded crown that serves well to provide shade in the landscape; the crown can hang quite low if the tree is not kept pruned. Yellowish-green flowers appear in late spring, giving way to the fruits that ripen into nuts in fall. The fall color is a fairly unremarkable yellow.
Andean walnut is a fast-growing, deciduous tree with a spreading or irregularly round crown, that can eventualy reach a height of 30 metres. The trunk usually is straight, with a diameter of up to 90 cm (35 inch), sometimes with a small buttress on large trees, and supports an irregular or rounded crown of ascending branches. The bark is thick, brown and slightly fissured. Around spring, it blooms small cream-coloured flowers on long slender clusters known as catkins, and with female and male flowers borne on separate catkins on the same tree. Fertilised female flowers develop into egg-shaped fruit, green when young becoming yellow when mature with a thick, pulpy rind.
Lara Walnut Tree is a variety that comes from France. It’s unique due to its spherical crown and the ability to bear fruits early. It is very resistant to diseases, and it’s easily maintained, making it perfect for any landscape. If planted in full sun or partial shade, which best works for them, the tree can reach 30 to 45 feet. Lara Walnut Tree is partially self-fertile and produces large, rough-shelled nuts. The harvest for this walnut type begins in late September and ends in late October.
The English walnut is a majestic tree with a broad crown. Grown as a shade tree, it also produces edible, nutrient-rich nuts used in all types of recipes or simply eaten raw. English walnut trees can live up to 150 years and grow more than 60 feet tall.The trunk has smooth silver-gray bark and young twigs are green. Branches grow gray or green in an upward pattern, giving the tree a high and broad canopy. Its pinnate green leaves turn bronze in the fall. The tree has inconspicuous flowers each spring. A green hull encloses a shell containing a tasty seed.
Manchurian Walnut is a large, broad and often multi-stemmed tree with ornamental qualities. This tree produces large, thick-shelled nuts that ripen in the fall. These edible walnuts are reportedly difficult to crack open. They are useful for attracting wildlife, especially squirrels. The Manchurian Walnut contains and exudes much lesser quantities of allelopathic compounds, such as juglone (common to walnuts), that may prevent or impair growth of nearby plants. Therefore, it is commonly embraced as a safe walnut to plant.
Japanese walnut is a deciduous tree that can grow up to 15 m tall. It has spreading branches that produce a wide canopy up to 15 m. It can live for over 50 years. The tree has very long leaves that are made up of many smaller, oval shaped, serrated, bright green leaflets. This tree produces an edible fruit which is sometimes also called a heartnut, due to its heart shape. The male flowers are inconspicuous yellow-green catkins produced in spring at the same time as the new leaves appear. The female flowers have pink/ red pistils.
Texas Walnut also called little black walnut, littleleaf walnut and Mexican walnut) grows as small to medium-sized tree, but it is often shrubby and multi-trunked, springing from many small stems. Its smooth or lightly furrowed branches form a broad, rounded crown. Pinnate foliage is long, narrow and yellow-green. Little walnut flowers in early spring but the nuts don’t ripen until late summer/fall. The small nut is encased in a leathery, green husk that slowly turns brown as it ripens. Inside the husk, the nut meat or cotyledon is surrounded by a woody pericarp or outer shell.
Chandler Walnut Tree is the most productive variety and it gives more walnuts than any other species of walnut. Chandler produces heavy crops of large, well-sealed nutswith light-colored kernels. Chandler is a widely planted walnut variety in California, and is good for backyard orchards because the tree is smaller than other walnut varieties. It is a self pollinating tree, it can yield walnuts without a pollenizer. Chandler grows in a moderately vigorous way and it is semi upright. Chandler walnut tree’s height can reach up to 15 meters.
The Franquette walnut made its appearance in Northern California in the late 1800s, and found favor among growers because it had a well-sealed shell, a flavorful and very good quality, light kernel, and as one of the last varieties to flower, it was less susceptible to spring frost. With their symmetrical, oval canopies and a broad branch structure, these feature wide, attractive leaves and bring a distinctive look to the landscape. Franquette is one of the most widely planted English Walnuts for commercial production. It produces delicious, sealed, thin-shelled nuts that are easy to harvest and process.
The Hartley Walnut Tree is an English-style walnut, a consistent producer with large, thin-shelled, well-sealed nuts and light-colored flavorful meats that was developed by the University of California.The nuts of the Hartley Walnut Tree are large, slightly pointed and delicious. The tree is medium to large and moderately spreading. They bloom late which avoids late Spring frosts and the nuts ripen in late September.
Pedro Walnut Tree is a small walnut species with a mature height of only 30 feet. It blooms and ripens very late. This walnut type cannot succeed in areas that are too hot. It requires full sun its best growth. Pedro Walnut Tree requires around 400 chilling hours to prosper. Their nuts are light green and smooth, and it’s said that they are among the tastiest nuts compared to other species.
Fernor walnut trees are walnut varieties that are come up late and harvested early. Fernor walnut trees were produced in France and are a cross between Franquette walnut and Lara walnut. Fernor produces nuts with thin shell. Its kernels are tasty and light-colored kernels. Fernor is a precocious fast growing variety and it starts producing walnuts 3 or 4 years after you plant the tree. It can yield up to 8 tons of walnuts per hectare when it reaches maturity.
Apollo Walnut Tree is a walnut tree type discovered in the Czech Republic. This species can be over 65 feet tall and have a lush, round crown. Their leaves are long, smooth, with 5 to 7 leaflets. This walnut will reach its true potential in moist soils and warm climates. Apollo walnut is very cold resistant and can last under extreme temperatures. Their nuts are egg-shaped, with a small spike at the top.
- Facts About Walnuts: https://en.m.wikipedia.org/wiki/Juglans
- Species of Walnut Trees: https://www.thespruce.com/walnut-tree-species-3269725
- Growing And Caring For Walnut Trees: https://plantvillage.psu.edu/topics/walnut/infos
- Growing Walnut Trees: https://www.permaculturenews.org/2016/11/23/essential-guide-everything-need-know-growing-walnuts-juglans-regia/
- Different Types of Walnut Trees: https://homeguides.sfgate.com/different-kinds-walnut-trees-37066.html