Little walnut (Juglans microcarpa) is also known as Nogalito, Texas walnut, Texas black walnut and rivern walnut. The plant grows as either a small tree or large shrub. Little walnut is suitable for any size property. Plant as a single specimen on a small lot where larger members of the walnut family will not fit. A group of the trees on a large property makes a very showy display.
Little walnut grows to a height of 20 to 30 feet with a broad, round-shape crown that develops a dense canopy of leaves. The tree first produces fruit when it is about 15 years old.
The tree may have a single trunk, or multiple trunks with gray to dark-brown bark. Yellow-green compound leaves are made up of 11 to 24 thin leaflets and are 9 to 12 inches long. The tree produces both male and female flowers on the same tree in May and June. The nuts follow the flowers and ripen from October to December.
The tree is native to Kansas, New Mexico, Oklahoma and Texas and is found growing in dry, rocky ravines, on the hillsides and along the banks of streams. Plant little walnut in full sun and a dry, sandy, loam, or clay, well-drained soil. The tree is hardy as far north as USDA Plant Hardiness Zone 6.
The walnuts are small with very little meat. They are food for squirrels and other small animals. The seed is edible for humans and is used to make oil. Plant the tree in a wildlife garden where it will attract birds and butterflies. The root stock is grafted to non-native walnut trees in Texas, making them viable in the state. The wood is used to manufacture cabinets, furniture, wood paneling and wood veneer. Plant the tree in groups to serve as a windbreak.
The walnut husk fly damages the fruit in late summer. Root or crown rot is a also serious problem for little walnut trees. The roots produce toxins that are harmful to apples, members of the Ericaceae and Potentilla families and the white pine. These plants should not be planted near the little walnut. Deep roots, which the plant needs for finding water in times of drought, make it hard to transplant.