Black walnut is a Chicago-area native tree that provides excellent shade for large properties.
Its fruit is a rounded, yellow-green husk containing a nut that is a food source for squirrels. Black walnut also attracts the banded hairstreak butterfly, serving as a caterpillar host.
Black walnut trees need to be sited with care, since the tree produces a chemical that is toxic to some other plants.
This species is native to the Chicago region according to Swink and Wilhelm’s Plants of the Chicago Region, with updates made according to current research.
- Family (English) Walnut
- Family (botanic) Juglandaceae
- Planting site City parkway, Residential and parks, Wide median
- Tree or plant type Tree
- Foliage Deciduous (seasonally loses leaves)
- Native locale Chicago area, Illinois, North America
- Size range Large tree (more than 40 feet)
- Mature height 50-75 feet
- Mature width 30-50 feet
- Light exposure Full sun (6 hrs direct light daily)
- Hardiness zones Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9
- Soil preference Alkaline soil, Moist, well-drained soil
- Tolerances Alkaline soil, clay soil, Occasional drought, Road salt
- Season of interest early fall
- Flower color and fragrance Inconspicuous
- Shape or form Round
- Growth rate Moderate
- Transplants well Yes
- Planting considerations May be difficult to find in nurseries, Messy fruit/plant parts
- Wildlife Cavity-nesting birds, Game mammals, Songbirds
- Has cultivars Yes