# Companion species

> Pick one native tree or shrub and see the species that share its ground in the wild, live under its canopy, or want the same sun, soil and climate in a yard.

Blue Whale Trees, a native tree nursery in the United States. Web version: https://bluewhaletrees.com/tools/companions/?species=rhodora

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 is left out. The Morton Arboretum lists rhododendron among the plants its juglone harms.

[What to plant under a black walnut](https://bluewhaletrees.com/articles/juglone-what-to-plant-under-a-black-walnut/index.html.md) tables the shrubs and small trees that two or more lists call tolerant and none calls sensitive.

## Rhodora grows in the Appalachians, rocky ground, swamps and wet flats

These natives share that ground, so they will look right together and want the same care.

- [American Mountain Ash](https://bluewhaletrees.com/plants/american-mountain-ash/index.html.md) (*Sorbus americana*): Small tree, 15–30 ft · shares the Appalachians and rocky ground
- [Mountain Maple](https://bluewhaletrees.com/plants/mountain-maple/index.html.md) (*Acer spicatum*): Small tree, 10–25 ft · shares the Appalachians and rocky ground
- [Mountain Laurel](https://bluewhaletrees.com/plants/mountain-laurel/index.html.md) (*Kalmia latifolia*): Shrub, 5–12 ft · shares the Appalachians and rocky ground
- [Roundleaf Serviceberry](https://bluewhaletrees.com/plants/roundleaf-serviceberry/index.html.md) (*Amelanchier sanguinea*): Shrub, 3–23 ft · shares the Appalachians and rocky ground
- [Pin Cherry](https://bluewhaletrees.com/plants/pin-cherry/index.html.md) (*Prunus pensylvanica*): Small tree, 15–40 ft · shares the Appalachians and rocky ground
- [Allegheny Plum](https://bluewhaletrees.com/plants/allegheny-plum/index.html.md) (*Prunus alleghaniensis*): Shrub, 3–20 ft · shares the Appalachians and rocky ground
- [Hillside Blueberry](https://bluewhaletrees.com/plants/hillside-blueberry/index.html.md) (*Vaccinium pallidum*): Shrub, 1–3 ft · shares the Appalachians and rocky ground
- [Mountain Winterberry](https://bluewhaletrees.com/plants/mountain-winterberry/index.html.md) (*Ilex montana*): Small tree, 20–40 ft · shares the Appalachians and rocky ground

## Trees to plant it under

Rhodora takes some shade, so it can live beneath these.

- [Northern White Cedar](https://bluewhaletrees.com/plants/northern-white-cedar/index.html.md) (*Thuja occidentalis*): Medium tree, Zones 2–7, 40–60 ft, Price on request. Shares rocky ground, swamps and wet flats in the wild.
- [Yellow Birch](https://bluewhaletrees.com/plants/yellow-birch/index.html.md) (*Betula alleghaniensis*): Large tree, Zones 3–7, 60–75 ft, Price on request. Shares the Appalachians, swamps and wet flats in the wild.
- [Red Spruce](https://bluewhaletrees.com/plants/red-spruce/index.html.md) (*Picea rubens*): Large tree, Zones 2–6, 60–75 ft, Price on request. Shares the Appalachians and rocky ground in the wild.
- [Sweet Birch (Black Birch)](https://bluewhaletrees.com/plants/sweet-birch/index.html.md) (*Betula lenta*): Medium tree, Zones 3–8, 40–70 ft, Price on request. Shares the Appalachians and rocky ground in the wild.
- [Chestnut Oak](https://bluewhaletrees.com/plants/chestnut-oak/index.html.md) (*Quercus montana*): Medium tree, Zones 4–8, 50–70 ft, Price on request. Shares the Appalachians and rocky ground in the wild.
- [Northern Red Oak](https://bluewhaletrees.com/plants/northern-red-oak/index.html.md) (*Quercus rubra*): Large tree, Zones 3–8, 50–75 ft, Price on request. Shares the Appalachians and rocky ground in the wild.

## Beside it

Plants that want the same sun and soil, for a bed, a hedge or a grove.

- [Bartram's Serviceberry](https://bluewhaletrees.com/plants/bartram-serviceberry/index.html.md) (*Amelanchier bartramiana*): Shrub, Zones 2–7, 2–8 ft, Price on request. Shares the Appalachians, rocky ground, swamps and wet flats in the wild.
- [Sweet Azalea](https://bluewhaletrees.com/plants/sweet-azalea/index.html.md) (*Rhododendron arborescens*): Shrub, Zones 4–8, 8–20 ft, Price on request. Shares the Appalachians, rocky ground, swamps and wet flats in the wild.
- [Squashberry](https://bluewhaletrees.com/plants/squashberry/index.html.md) (*Viburnum edule*): Shrub, Zones 2–8, 2–7 ft, Price on request. Shares the Appalachians, swamps and wet flats in the wild.
- [Maleberry](https://bluewhaletrees.com/plants/maleberry/index.html.md) (*Lyonia ligustrina*): Shrub, Zones 5–9, 6–12 ft, Price on request. Shares the Appalachians, swamps and wet flats in the wild. Hardy in zones 5 to 6 of the rhodora's 4 to 6.
- [Canada Yew](https://bluewhaletrees.com/plants/canada-yew/index.html.md) (*Taxus canadensis*): Shrub, Zones 2–7, 3–6 ft, Price on request. Shares the Appalachians, swamps and wet flats in the wild.
- [Pinxterbloom Azalea](https://bluewhaletrees.com/plants/pinxterbloom-azalea/index.html.md) (*Rhododendron periclymenoides*): Shrub, Zones 4–9, 3–6 ft, Price on request. Shares the Appalachians, swamps and wet flats in the wild.
- [When these flower and fruit](https://bluewhaletrees.com/tools/calendar/#plants=rhodora,northern-white-cedar,yellow-birch,red-spruce,sweet-birch,chestnut-oak,northern-red-oak,bartram-serviceberry,sweet-azalea,squashberry,maleberry,canada-yew,pinxterbloom-azalea), in the bloom and fruit calendar.

## Email me when Rhodora or a companion is ready to order

For Rhodora, Northern White Cedar, Yellow Birch, Red Spruce, Sweet Birch (Black Birch), Chestnut Oak, Northern Red Oak, Bartram's Serviceberry, Sweet Azalea, Squashberry, Maleberry, Canada Yew: 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](https://bluewhaletrees.com/tools/native/index.html.md) 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](https://bluewhaletrees.com/articles/what-to-plant-under-a-big-tree/index.html.md) and [the article on juglone](https://bluewhaletrees.com/articles/juglone-what-to-plant-under-a-black-walnut/index.html.md) 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](https://bluewhaletrees.com/tools/site-check/index.html.md) for the spot itself, and the [growth estimator](https://bluewhaletrees.com/tools/growth/index.html.md) for how much room each one will want in twenty years.