What it needs & gives back
↓ Needs
Lightfull sun to partial shade
Watermedium
↑ Gives back
Shadedense
Mulch_biomasshigh
Companions
treetreetree
Northern Red Oak
Often found growing together in natural woodlands, showing some tolerance to juglone.
Black locust
Black locust is tolerant of juglone and can fix nitrogen, potentially benefiting nearby walnuts.
Shagbark hickory
Hickories are tolerant of juglone and often grow with black walnut.
Keep apart from
plantTomatoJuglone produced by black walnut is toxic to tomatoes.shrubHighbush BlueberryJuglone produced by black walnut is toxic to blueberries.treeAppleJuglone produced by black walnut is toxic to apple trees.treeHeartnutProduces juglone, which is allelopathic to many plants, similar to black walnut.treeButternutButternut, like Black Walnut, produces juglone, which can inhibit the growth of sensitive plants.
Through the year
Through the year
JFMAMJJASOND
emergenceSeedlings emerge after the last spring frost when soil temperatures consistently reach 10°C.
floweringFlowering occurs approximately 30 days after emergence, typically in late spring.
fruitingFruits develop over the summer, maturing about 90 days after flowering.
harvestNuts typically fall from the trees in September and October.
senescenceLeaves begin to change color and drop with the first autumn frosts and shortening days.
dormancyTrees enter dormancy after leaf drop, lasting through winter until chill requirements are met.
Soil interactions
Drainagewell-drained to moist
Nitrogen fixingNo
MycorrhizalYes
Accumulatespotassium, phosphorus
Soil textureloam, silt
Organic matterHigh
Compaction toleranceMedium
Propagation
Methodsseed, grafting
Difficulty3 / 5
Establishes in~3 yr
Stratificationrequires 90-120 days of cold stratification (0-5°C)
Self-seedingModerate
Divisionnot applicable
Wildlife & pests
Attractssquirrels, birds
Can host pestswalnut husk fly, codling moth
Can host diseasesanthracnose, bacterial blight