Black Walnut
Juglans nigra
Black Walnut (Juglans nigra) is a tree suited to the Colorado Front Range, rated "Not Recommended" on the 2024 Front Range Tree Recommendation List. It matures to about 50–75 ft tall and 50–70 ft wide, and needs low to medium water. Black walnut produces juglone, which inhibits many garden plants under its canopy; large messy nuts and limb drop are landscape liabilities. Do not plant in residential lots.
low to medium water50–75 ft tall and 50–70 ft wideXeric / water-wiseDeer-resistantToxic to dogs
Photos
At a glance
- Rating
- Not Recommended
- Botanical name
- Juglans nigra
- Variety / cultivar
- Black Walnut
- Type
- Tree
- Mature size
- 50–75 ft tall and 50–70 ft wide
- Water needs
- low to medium water
- Colorado native
- No
- Foliage
- Deciduous
- Soil
- clay, loam, sandy
- Soil pH
- 6.0–8.2
- Hail tolerance
- moderate
- Wind tolerance
- moderate
- Salt tolerance
- moderate
Site factors to consider
- Critical: Insects & Diseases
Planting & establishment
Water deeply every 7–10 days through the first 2 summers. Winter water 1–2×/month October–March when soil is dry and unfrozen — winter desiccation is a top killer of newly-planted trees. Year 3: taper to 2×/month in summer, then rely on natural precipitation.
Frequently asked questions
- Is Black Walnut good for the Colorado Front Range?
- Yes. Black Walnut is included in the Front Range Plant Finder as a tree suited to Colorado's Front Range, rated "Not Recommended" on the 2024 Front Range Tree Recommendation List.
- How big does Black Walnut get?
- It matures to about 50–75 ft tall and 50–70 ft wide.
- How much water does Black Walnut need?
- It needs low to medium water once established.
- Is Black Walnut safe for dogs?
- No — Black Walnut is considered toxic to dogs. Keep pets away and check with your vet.
