Black Walnut Plant Care

Black Walnut (Juglans nigra) belongs to the Juglandaceae family within the Juglans genus. Black Walnut is native to central and eastern North America, growing mostly in riparian zones. Black Walnut is also known as Eastern Black Walnut, American Black Walnut.

Black Walnut displays a tall, deciduous tree growth habit, reaching up to 100 inches tall with a spread of approximately 50 inches. Black Walnut produces inconspicuous greenish flowers.

Leaf size: approximately 12 inches.

Juglans nigra requires watering every 7–14 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.

Black Walnut thrives in full sun light conditions. The optimal light range is 2000–5000 lux. Avoid placing Black Walnut in direct, harsh sunlight for extended periods, as this can scorch the foliage.

Juglans nigra grows best at temperatures between 0°F and 100°F. Black Walnut prefers humidity levels of 30–70%.

Rich, well-draining soil with good organic content. Good drainage is essential for Black Walnut to prevent waterlogging, which leads to root rot and fungal issues.

Repot every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.

Black Walnut can be propagated through seeds, grafting.

Black Walnut is susceptible to walnut caterpillars, walnut husk flies. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.