Shrubs that grow well under walnut trees are plants that can tolerate shade, dry soil, and a natural chemical produced by walnut roots and leaves called juglone. Walnut trees release this substance into the soil, which can slow or prevent the growth of sensitive plants. Shrubs that thrive in these areas are known as juglone-tolerant species.
Growing conditions beneath walnut trees can be challenging because the dense canopy blocks sunlight and the large root system competes strongly for water and nutrients. Successful shrubs are usually shade-tolerant and able to grow with limited moisture. Once established, these hardy plants adapt well to the competition.
Shrubs suited for planting under walnut trees often have strong root systems and flexible growth habits. Many woodland shrubs naturally grow in similar environments where they compete with large trees. These plants can survive filtered light and benefit from the leaf mulch that accumulates beneath the tree.
Proper planting techniques improve success in these conditions. Adding compost helps improve soil structure, while watering young shrubs regularly during establishment allows them to develop deeper roots. Mulching can conserve moisture and reduce stress caused by root competition from the walnut tree.
Black walnut trees produce juglone (5-hydroxy-1,4-naphthoquinone) in their roots, leaves, hulls, and bark that inhibits the growth of many sensitive plants. The toxic zone extends 50-80 feet from the trunk and persists in soil for years after tree removal.
Sensitive plants show symptoms including yellowing leaves, wilting, and death. However, many shrubs have developed tolerance to juglone and can thrive in walnut’s presence, making proper plant selection essential for successful gardening under these trees.
Shrubs That Grow Well Under Walnut Trees
Forsythia
Forsythia is one of the most reliably juglone-tolerant shrubs, thriving under and around black walnut trees with minimal stress. These vigorous, deciduous shrubs produce spectacular yellow flowers in early spring before leaves emerge, creating brilliant displays even in challenging walnut-influenced soil.
Forsythia’s adaptability to various soil conditions including the altered chemistry created by juglone makes it an excellent choice for planting under walnuts. The shrub’s vigor and adaptability allow it to compete successfully with walnut’s chemical and physical root competition while providing seasonal interest.
Viburnum
Most viburnum species demonstrate good juglone tolerance, thriving in the challenging conditions found under black walnut trees. These versatile shrubs provide fragrant spring flowers, attractive berries, excellent fall color, and important wildlife habitat while tolerating walnut’s chemical influence.
Arrowwood viburnum, blackhaw viburnum, and nannyberry are particularly reliable choices that handle juglone well while providing multi-season ornamental interest. The combination of adaptability, multi-season interest, and juglone tolerance makes viburnums among the most valuable shrubs for walnut tree understory planting.
Elderberry
Elderberry demonstrates excellent tolerance of juglone and naturally grows in similar habitats to black walnut trees throughout its native range. These large, fast-growing shrubs produce flat-topped white flower clusters and dark purple berries valuable for syrups, wines, and wildlife food.
Elderberry’s vigorous growth and adaptability allow it to thrive despite juglone presence, and the shrub’s deep roots help it access nutrients and moisture below the zone of greatest juglone concentration. The edible berries, wildlife value, and juglone tolerance make elderberry an excellent functional shrub under walnuts.
Spicebush
Spicebush grows naturally alongside black walnuts in woodland settings and demonstrates good tolerance of juglone in its native habitat. These aromatic native shrubs produce tiny yellow flowers in early spring, bright red berries, and aromatic leaves that emit a spicy fragrance when crushed.
Spicebush is an important host plant for Spicebush Swallowtail butterflies and provides excellent wildlife habitat. The natural co-occurrence with black walnuts, wildlife benefits, early spring flowers, and aromatic properties make spicebush one of the most ecologically appropriate shrubs for walnut understory planting.
Virginia Sweetspire (Itea)
Virginia sweetspire shows good tolerance of juglone and adapts well to the challenging conditions under black walnut trees. These native shrubs produce fragrant white flower spikes in summer and develop spectacular fall color ranging from orange to crimson to purple.
Virginia sweetspire tolerates the wet, shaded conditions often found under walnut canopies while demonstrating resistance to juglone’s effects. The fragrant flowers, exceptional fall color, and adaptability to walnut-influenced soil make itea an excellent native shrub for understory planting beneath black walnuts.
Native Wild Ginger (Shrub Form)
Wild ginger demonstrates tolerance of juglone and naturally grows in woodland settings alongside black walnuts throughout its native range. While typically considered a groundcover, large clumps of wild ginger develop woody characteristics making it a shrub-like presence in walnut understory plantings.
The attractive, heart-shaped leaves create dense groundcover while tolerating walnut’s chemical influence, and the plant’s native woodland adaptation makes it perfectly suited to growing under walnut canopies with their characteristic shade and root competition.
Juneberry (Serviceberry)
Serviceberry or juneberry demonstrates juglone tolerance and naturally grows in woodland edges where black walnuts are common. These multi-stemmed shrubs or small trees produce beautiful white spring flowers, sweet edible berries in early summer, and excellent fall color.
Serviceberry’s native woodland adaptation allows it to handle the chemical and competitive challenges of growing near black walnuts while providing multi-season ornamental interest and edible fruit. The attractive flowers, tasty berries, fall color, and juglone tolerance make serviceberry an outstanding choice for walnut understory plantings.
Black Raspberry
Black raspberry canes demonstrate good juglone tolerance and can thrive under and around black walnut trees where many other plants fail. These arching, thorny shrubs produce sweet, complex-flavored black raspberries in summer while tolerating walnut’s chemical influence.
Black raspberry’s adaptability to woodland edges and partial shade matches the conditions typically found under walnut canopies, and the edible fruit provides practical rewards for gardeners willing to plant in challenging walnut-influenced sites.
Staghorn Sumac
Staghorn sumac demonstrates tolerance of juglone and grows vigorously in the challenging conditions found near black walnut trees. These large, spreading shrubs develop velvety, antler-like branches, dramatic tropical-looking compound leaves, and brilliant fall color.
Staghorn sumac spreads through root suckers but tolerates juglone well, making it useful for naturalizing large areas under walnut trees. The dramatic form, exceptional fall color, and tolerance of walnut’s chemical influence make staghorn sumac effective for large-scale walnut understory planting.
Aronia (Chokeberry)
Aronia demonstrates good juglone tolerance and adapts well to the challenging conditions created by black walnut trees. These native shrubs produce white spring flowers, dark purple-black or red berries, and exceptional fall color while tolerating walnut’s chemical effects.
Both red chokeberry and black chokeberry handle juglone influence reasonably well, and their adaptability to wet, shaded conditions matches the environment often found under walnut canopies. The multi-season ornamental interest, wildlife value, and juglone tolerance make aronia excellent for walnut understory shrub plantings.
Smooth Hydrangea
Smooth hydrangea like Annabelle demonstrates surprising juglone tolerance and can succeed in walnut understory situations when planted beyond the immediate root zone. These native shrubs produce enormous white flower clusters in summer and tolerate the partial shade found under walnut canopies.
Smooth hydrangea’s adaptability to various soil conditions including walnut-influenced sites makes it useful for adding large, showy flowers to challenging areas. The spectacular blooms, adaptability, and reasonable juglone tolerance make smooth hydrangea a rewarding choice for walnut understory planting.
Wild Black Currant
Wild black currant demonstrates good tolerance of juglone and naturally grows in woodland settings where black walnuts are common. These productive shrubs produce tart black currants with excellent nutritional value while tolerating walnut’s chemical influence.
The shrubs prefer partial shade and moist conditions, matching the environment found under walnut canopies, and their natural woodland adaptation makes them well-suited to competing with walnut’s root system for moisture and nutrients.
Fragrant Sumac
Fragrant sumac is a low-growing, adaptable shrub that demonstrates juglone tolerance and thrives in challenging conditions. These spreading shrubs reach 4-6 feet tall with aromatic foliage, small yellow spring flowers, and brilliant orange-red fall color.
Fragrant sumac spreads through underground stems but tolerates juglone well and adapts to the dry, shaded conditions often found under walnut canopies. The aromatic leaves, fall color, and tolerance of challenging walnut-influenced conditions make fragrant sumac useful for naturalizing areas beneath walnuts.
Pawpaw
Pawpaw naturally grows in the same woodland habitats as black walnut and demonstrates excellent tolerance of juglone as a co-evolved species. These understory shrubs or small trees produce tropical-tasting fruits and are naturally adapted to growing under larger canopy trees including walnuts.
The native co-occurrence of pawpaws and black walnuts throughout eastern North American forests demonstrates their compatibility, and pawpaws’ edible tropical-tasting fruits make them particularly rewarding to grow in challenging walnut-influenced sites.
Native Plum (Prunus americana)
American native plum demonstrates reasonable juglone tolerance compared to sensitive Prunus species, growing in woodland edges where walnuts are present. These thorny shrubs produce fragrant white spring flowers and tart plums used for jellies and preserves while tolerating walnut-influenced soil conditions.
The shrub’s native woodland adaptation helps it compete with walnut’s physical and chemical influence, and the spring flowers, edible fruit, and wildlife value make native plum a worthwhile addition to walnut understory plantings.
Witch Hazel
Witch hazel demonstrates good tolerance of juglone and naturally grows in woodland settings similar to black walnut habitat. These large shrubs produce fragrant yellow, orange, or red flowers in fall or winter when few other plants bloom, creating unique seasonal interest under walnut canopies.
Witch hazel’s native woodland adaptation and preference for similar habitat conditions makes it well-suited to competing with black walnuts, and the unusual late-season fragrant flowers and excellent fall color provide ornamental value in challenging sites.
Buttonbush
Buttonbush demonstrates juglone tolerance and grows naturally in wet woodland settings where black walnuts may be present. These native shrubs produce unique white spherical flower heads in summer that attract pollinators and provide important wildlife habitat.
Buttonbush tolerates the wet, shaded conditions often found in woodland areas with black walnuts, and its native adaptation to challenging moisture conditions helps it compete with walnut’s root system. The unique flowers, wildlife value, and juglone tolerance make buttonbush suitable for moist walnut understory situations.
Autumn Olive (With Caution)
Autumn olive demonstrates good juglone tolerance and grows vigorously near black walnuts, but should be planted with caution as it’s invasive in many regions. These nitrogen-fixing shrubs produce fragrant flowers and abundant berries while tolerating walnut’s chemical influence.
The nitrogen fixation actually helps improve soil quality under walnuts while the shrub’s vigor allows it to compete successfully. However, due to invasive tendencies, autumn olive should only be considered in regions where it cannot escape cultivation or where legal to plant.
Red Osier Dogwood
Red osier dogwood demonstrates good juglone tolerance and thrives in moist, shaded conditions found under black walnut trees. These native shrubs provide year-round interest through brilliant red winter stems, white spring flowers, white berries, and attractive fall foliage.
Red osier dogwood’s adaptability to wet conditions and partial shade matches the environment under walnut canopies, and the shrub’s vigorous growth allows it to compete with walnut’s physical and chemical challenges while providing exceptional multi-season ornamental value.
Ninebark
Ninebark demonstrates reasonable juglone tolerance and adapts to the challenging conditions found under black walnut trees. These native shrubs produce attractive peeling bark, white or pink spring flowers, and foliage in burgundy, gold, or green depending on cultivar.
Ninebark’s adaptability to various soil conditions and its native woodland edge habitat makes it suitable for walnut understory planting, and the colorful foliage options and interesting bark provide ornamental interest in challenging sites.
Rosa setigera (Climbing Prairie Rose)
Native climbing prairie rose demonstrates better juglone tolerance than many ornamental roses and can succeed in walnut understory situations. These vigorous native roses produce clusters of pink flowers in early summer and develop arching canes that can sprawl along the ground under walnut canopies.
The prairie rose’s native woodland adaptation and tolerance of partial shade and variable soil conditions makes it better suited to walnut understory planting than hybrid roses, and the attractive flowers and rose hips provide ornamental and wildlife value.
Hazelnut (Corylus americana)
American hazelnut naturally grows in woodland settings alongside black walnuts throughout eastern North America, demonstrating good juglone tolerance. These productive shrubs reach 8-12 feet tall and produce edible hazelnuts along with early catkins and attractive fall color.
American hazelnut’s native co-occurrence with black walnuts throughout their shared range demonstrates their compatibility, and the edible nut production, wildlife value, and attractive form make hazelnut one of the most rewarding shrubs to plant in walnut understory situations.
Smooth Sumac
Smooth sumac demonstrates strong juglone tolerance and grows vigorously in the challenging conditions created by black walnut trees. These spreading shrubs develop spectacular compound leaves with brilliant red fall color and dense red fruit clusters that persist through winter providing wildlife food.
Smooth sumac spreads aggressively through root suckers and is best used in naturalized areas under walnuts where spreading is acceptable. The exceptional fall color, winter fruit, tolerance of walnut’s chemical influence, and adaptability to dry, shaded conditions make smooth sumac excellent for naturalizing large areas beneath black walnut trees.