Wild Black Currant
Ribes americanum Shrub Zones 3–7 3–6 ft
Shares floodplain forests and rich moist slopes in the wild. Hardy in zones 4 to 7 of the black walnut's 4 to 9. On Morton's tolerant list as “Currant (Ribes spp.)”.
Companion species
Pick one native tree or shrub and see what grows with it. The matches come in three groups. Some species share its ground in the wild, and others live under its canopy or are the trees it can be planted beneath. The rest suit the same yard because they want the same sun, soil and climate. Every match is explained on the page, so you can see why a species is listed.
Black walnut's roots release juglone, which harms some plants. The Morton Arboretum lists rhododendron, linden, crabapple, yew, hackberry, blueberry, red chokeberry and larch as sensitive, so the 37 trees and shrubs of those kinds that we grow are left out here. The species it lists as tolerant are marked, and come first in the yard lists. The rest are on neither of its lists, which it calls incomplete.
The 37 species left out
Alabama azalea, American basswood, American crabapple, Canada yew, Catawba rhododendron, coastal azalea, common hackberry, creeping blueberry, Cumberland azalea, deerberry, dwarf hackberry, Elliott's blueberry, farkleberry, flame azalea, Florida flame azalea, Florida yew, hairy blueberry, hillside blueberry, May white azalea, minnie-bush, Oconee azalea, Piedmont azalea, Piedmont rhododendron, pinkshell azalea, pinxterbloom azalea, plumleaf azalea, prairie crabapple, rabbiteye blueberry, red chokeberry, Red Hills azalea, rhodora, rosebay rhododendron, southern crabapple, sugarberry, swamp azalea, sweet azalea and tamarack.
What to plant under a black walnut tables the shrubs and small trees that two or more lists call tolerant and none calls sensitive.
In the wild
Black Walnut grows in floodplain forests and rich moist slopes
These natives share that ground, so they will look right together and want the same care.
Morus rubra Medium tree, 35–50 ft
Euonymus atropurpureus Shrub, 6–20 ft
Aralia spinosa Small tree, 10–20 ft · on Morton's tolerant list
Juglans cinerea Medium tree, 40–60 ft
Acer nigrum Large tree, 60–75 ft
Gymnocladus dioicus Large tree, 60–80 ft
Ilex opaca Medium tree, 20–50 ft
Euonymus americanus Shrub, 4–6 ft
In the yard
Under its canopy
Shrubs and small trees that take the shade a black walnut casts and like the same soil.
American Hornbeam (Musclewood)
Carpinus caroliniana Small tree Zones 3–9 20–35 ft
Shares floodplain forests in the wild. On Morton's tolerant list as “American hornbeam (Carpinus caroliniana)”.
Spicebush
Lindera benzoin Shrub Zones 4–9 6–12 ft
Shares floodplain forests in the wild. On Morton's tolerant list as “Spicebush (Lindera benzoin)”.
Wild Hydrangea
Hydrangea arborescens Shrub Zones 3–9 3–6 ft
Shares rich moist slopes in the wild. On Morton's tolerant list as “Wild hydrangea (Hydrangea arborescens)”.
Pawpaw
Asimina triloba Small tree Zones 5–9 15–30 ft
Shares floodplain forests in the wild. Hardy in zones 5 to 9 of the black walnut's 4 to 9. On Morton's tolerant list as “Pawpaw (Asimina triloba)”.
Witch Hazel
Hamamelis virginiana Shrub Zones 3–8 12–20 ft
Shares rich moist slopes in the wild. Hardy in zones 4 to 8 of the black walnut's 4 to 9. On Morton's tolerant list as “Witch-hazel (Hamamelis spp.)”.
In the yard
Beside it
Plants that want the same sun and soil, for a bed, a hedge or a grove, with the same size class first.
Bitternut Hickory
Carya cordiformis Large tree Zones 4–9 50–80 ft
Shares floodplain forests and rich moist slopes in the wild. On Morton's tolerant list as “Hickory (Carya spp.)”.
American Beech
Fagus grandifolia Large tree Zones 3–9 50–80 ft
Shares floodplain forests and rich moist slopes in the wild. On Morton's tolerant list as “American beech (Fagus grandifolia)”.
Yellow Buckeye
Aesculus flava Large tree Zones 3–8 50–75 ft
Shares floodplain forests and rich moist slopes in the wild. Hardy in zones 4 to 8 of the black walnut's 4 to 9. On Morton's tolerant list as “Yellow buckeye (Aesculus octandra)”.
Southern Shagbark Hickory
Carya carolinae-septentrionalis Large tree Zones 5–8 70–125 ft
Shares floodplain forests and rich moist slopes in the wild. Hardy in zones 5 to 8 of the black walnut's 4 to 9. On Morton's tolerant list as “Hickory (Carya spp.)”.
White Oak
Quercus alba Large tree Zones 3–9 50–80 ft
Shares rich moist slopes in the wild. On Morton's tolerant list as “White oak (Quercus alba)”.
Mockernut Hickory
Carya tomentosa Large tree Zones 4–9 60–80 ft
Shares rich moist slopes in the wild. On Morton's tolerant list as “Hickory (Carya spp.)”.
Plan the planting
- When these flower and fruit, in the bloom and fruit calendar.
- What to plant under a big tree, and how to plant without harming its roots.
- The habitat around a tree is part of the tree: what keeps its roots alive.
Be first
Email me when Black Walnut or a companion is ready to order
For Black Walnut, Wild Black Currant, American Hornbeam (Musclewood), Spicebush, Wild Hydrangea, Pawpaw, Witch Hazel, Bitternut Hickory, American Beech, Yellow Buckeye, Southern Shagbark Hickory, White Oak: one email per plant when it is priced or back in stock, and nothing else.
How the matches are made
- Natural communities. Every species we grow is tagged with the communities it lives in: floodplain forests, swamps and wet flats, stream banks, rich moist slopes, dry uplands, sandy barrens, rocky ground, old fields and edges, the forest understory, the Appalachians and the coast.
- In the wild. Up to eight natives that share one of those communities with it and grow wild in one of its states. The most communities in common come first, then the native range most like its own. A species in a yard list is not repeated here.
- Under its canopy, or trees to plant it under. Up to six species at least two sizes apart, the smaller one taking part shade or shade: shrubs under a medium tree, shrubs and small trees under a large one.
- Beside it. Up to six that share a sun with it, the same size first.
- The order of a yard list. Every yard pick shares a zone, a soil and a state of native range with it. A shared community counts two points, and a shared sun or soil one. Under a canopy, a species of the forest understory counts two more, and one that takes full shade one more. Of equal scores, the one hardy in more of its zones comes first.
- Your zone. With a zone chosen, the yard lists keep only species rated hardy in it.
- Black walnut. The 37 species we grow that the Morton Arboretum lists as sensitive to its juglone are left out of its answer, and it is left out of theirs. Under a walnut, the species on Morton's tolerant lists come first and are marked.
- Eastern red cedar. The 25 crabapples, hawthorns, serviceberries, chokeberries and mountain ash we grow are left out of its answer, and it is left out of theirs: the cedar-apple, hawthorn, quince and juniper broom rusts live on both, and the University of Minnesota Extension says to keep them a few hundred yards apart.
- A tree we do not grow. The note under the menu names a relative we grow, in the words of its page.
The communities are our own tags. The states of native range are the USDA PLANTS Database's records, read on 2026-09-23, as the native trees by state tool reads them. Zones, sun and soil are each species' own page. The juglone lists are the Morton Arboretum's, read on 2026-10-05, which warns that "any list regarding this topic is incomplete and some of the information may be anecdotal." The rusts' hosts are the University of Minnesota Extension's, read on 2026-10-06. What to plant under a big tree and the article on juglone cover the subject.
Sharing a habitat tag does not mean two plants always grow side by side, and a tag says nothing about how far apart to plant them. Use the planting-site check for the spot itself, and the growth estimator for how much room each one will want in twenty years.