# Companion species

> Natives to grow with sweetfern: 8 from its wild ground, 6 trees to plant it under and 6 beside it.

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

Try [black walnut](https://bluewhaletrees.com/tools/companions/index.html.md?species=black-walnut), [flowering dogwood](https://bluewhaletrees.com/tools/companions/index.html.md?species=flowering-dogwood) or [spicebush](https://bluewhaletrees.com/tools/companions/index.html.md?species=spicebush).

A native tree or shrub has companions, in the wild and in a yard. 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.

Sweetfern is not a tree or shrub we grow, so it has no sign-up here; [its page](https://bluewhaletrees.com/species/sweetfern/index.html.md) gathers what our tools say about it. Its figures come from Silvics of North America, NC State Extension, the Missouri Botanical Garden, the Morton Arboretum, the Wildflower Center, the Forest Service's Fire Effects Information System, the University of Connecticut's plant database and the USDA PLANTS Database.

## Sweetfern grows in sandy barrens, dry uplands, old fields and edges

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

- [Gray Birch](https://bluewhaletrees.com/plants/gray-birch/index.html.md) (*Betula populifolia*): Small tree, 20–40 ft
- [Common Juniper](https://bluewhaletrees.com/plants/common-juniper/index.html.md) (*Juniperus communis*): Shrub, 2–10 ft
- [Dwarf Hackberry](https://bluewhaletrees.com/plants/dwarf-hackberry/index.html.md) (*Celtis tenuifolia*): Small tree, 15–30 ft
- [Bristly Locust (Rose Locust)](https://bluewhaletrees.com/plants/rose-locust/index.html.md) (*Robinia hispida*): Shrub, 3–8 ft
- [Farkleberry](https://bluewhaletrees.com/plants/farkleberry/index.html.md) (*Vaccinium arboreum*): Small tree, 10–25 ft
- [Flatwoods Plum](https://bluewhaletrees.com/plants/flatwoods-plum/index.html.md) (*Prunus umbellata*): Small tree, 12–20 ft
- [Gum Bumelia](https://bluewhaletrees.com/plants/gum-bumelia/index.html.md) (*Sideroxylon lanuginosum*): Small tree, 15–45 ft
- [Woolly Pawpaw](https://bluewhaletrees.com/plants/woolly-pawpaw/index.html.md) (*Asimina incana*): Shrub, 4–6 ft

How far apart: the [planting-distance tool](https://bluewhaletrees.com/tools/distance/index.html.md?species=sweetfern&near=tree) gives the gap between Sweetfern and any tree you name as the next one, by their pages' spacing or half of each crown, added.

## Trees to plant it under

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

- [Sassafras](https://bluewhaletrees.com/plants/sassafras/index.html.md) (*Sassafras albidum*): Medium tree, Zones 4–9, 30–60 ft, Price on request. Shares sandy barrens, dry uplands, old fields and edges in the wild. Hardy in zones 4 to 6 of the sweetfern's 2 to 6.
- [Slippery Elm](https://bluewhaletrees.com/plants/slippery-elm/index.html.md) (*Ulmus rubra*): Medium tree, Zones 3–9, 40–70 ft, Price on request. Shares dry uplands, old fields and edges in the wild. Hardy in zones 3 to 6 of the sweetfern's 2 to 6.
- [Black Gum (Tupelo)](https://bluewhaletrees.com/plants/black-gum/index.html.md) (*Nyssa sylvatica*): Large tree, Zones 4–9, 40–70 ft, Price on request. Shares dry uplands, old fields and edges in the wild. Hardy in zones 4 to 6 of the sweetfern's 2 to 6.
- [Shingle Oak](https://bluewhaletrees.com/plants/shingle-oak/index.html.md) (*Quercus imbricaria*): Medium tree, Zones 4–8, 40–60 ft, Price on request. Shares dry uplands, old fields and edges in the wild. Hardy in zones 4 to 6 of the sweetfern's 2 to 6.
- [American Persimmon](https://bluewhaletrees.com/plants/american-persimmon/index.html.md) (*Diospyros virginiana*): Medium tree, Zones 4–9, 35–60 ft, Price on request. Shares sandy barrens, old fields and edges in the wild. Hardy in zones 4 to 6 of the sweetfern's 2 to 6.
- [Black Cherry](https://bluewhaletrees.com/plants/black-cherry/index.html.md) (*Prunus serotina*): Large tree, Zones 2–9, 50–80 ft, Price on request. Shares dry uplands, old fields and edges in the wild.

Ask what is ready: [put these 6 on my request list](https://bluewhaletrees.com/list/#items=sassafras:1,slippery-elm:1,black-gum:1,shingle-oak:1,american-persimmon:1,black-cherry:1).

Want one of these? Email me when it is ready to order.

## Beside it

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

- [Dangleberry](https://bluewhaletrees.com/plants/dangleberry/index.html.md) (*Gaylussacia frondosa*): Shrub, Zones 5–9, 2–6 ft, Price on request. Shares sandy barrens, dry uplands, old fields and edges in the wild. Hardy in zones 5 to 6 of the sweetfern's 2 to 6.
- [Running Serviceberry](https://bluewhaletrees.com/plants/running-serviceberry/index.html.md) (*Amelanchier spicata*): Shrub, Zones 4–8, 1–6 ft, Price on request. Shares sandy barrens, dry uplands, old fields and edges in the wild. Hardy in zones 4 to 6 of the sweetfern's 2 to 6.
- [New Jersey Tea](https://bluewhaletrees.com/plants/new-jersey-tea/index.html.md) (*Ceanothus americanus*): Shrub, Zones 4–8, 2–3 ft, Price on request. Shares sandy barrens, dry uplands, old fields and edges in the wild. Hardy in zones 4 to 6 of the sweetfern's 2 to 6.
- [Prairie Redroot](https://bluewhaletrees.com/plants/prairie-redroot/index.html.md) (*Ceanothus herbaceus*): Shrub, Zones 4–8, 2–3 ft, Price on request. Shares sandy barrens, dry uplands, old fields and edges in the wild. Hardy in zones 4 to 6 of the sweetfern's 2 to 6.
- [Hillside Blueberry](https://bluewhaletrees.com/plants/hillside-blueberry/index.html.md) (*Vaccinium pallidum*): Shrub, Zones 5–9, 1–3 ft, Price on request. Shares sandy barrens, dry uplands, old fields and edges in the wild. Hardy in zones 5 to 6 of the sweetfern's 2 to 6.
- [Coral Bean](https://bluewhaletrees.com/plants/coral-bean/index.html.md) (*Erythrina herbacea*): Shrub, Zones 6–10, 3–12 ft, Price on request. Shares sandy barrens, dry uplands, old fields and edges in the wild. Hardy only in zone 6 of the sweetfern's 2 to 6.
- [When these flower and fruit](https://bluewhaletrees.com/tools/calendar/index.html.md?plants=sweetfern,sassafras,slippery-elm,black-gum,shingle-oak,american-persimmon,black-cherry,dangleberry,running-serviceberry,new-jersey-tea,prairie-redroot,hillside-blueberry,coral-bean), in the bloom and fruit calendar.

## Email me when one of these companions is ready to order

Limited time Sign up now and get **10% off** when it is ready.

One email per plant you tick, when it is priced, and nothing else. Each carries a code for 10% off the plants in that order, not shipping or tax. Or ask, and we reply with what is ready now.

## 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.
- **How far apart.** Each yard card links the planting-distance tool with both trees named. The tool gives the gap between them: each one's own spacing from its page, or half of each crown added, unless a page gives a larger distance from other trees. The wild list links the same tool with the chosen tree set, for any next tree you name.
- **Your zone.** With a zone chosen, the yard lists keep only species rated hardy in it.
- **Black walnut.** The 45 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 28 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 or shrub we do not grow.** The 45 common natives under their own group in the menu take the same tests, with their ground, zones, sun, soil and states of native range from their sources (Silvics of North America, the USDA PLANTS Database, the Woody Plant Seed Manual, the Fire Effects Information System and extension and botanical garden pages). The answer says so, links the species' own page, and offers the sign-up for the companions only.

## Common questions

### What can I plant under a black walnut tree?

Under a black walnut, the tool puts first the species on the Morton Arboretum's tolerant lists, such as [pawpaw](https://bluewhaletrees.com/plants/pawpaw/index.html.md), [spicebush](https://bluewhaletrees.com/plants/spicebush/index.html.md) and [flowering dogwood](https://bluewhaletrees.com/plants/flowering-dogwood/index.html.md). It leaves out those Morton lists as sensitive to the walnut's juglone, and Morton warns that any such list is incomplete.

### What should you not plant near a black walnut?

Of the trees and shrubs we grow, the Morton Arboretum lists crabapples, hackberries, lindens, rhododendrons, blueberries, larch, yew and red chokeberry as sensitive to black walnut's juglone. Azaleas count among the rhododendrons, and the tool keeps all of them out of a walnut's answer.

### What can I plant under a big tree?

Under a large tree, the tool lists up to six shrubs and small trees that take part shade or shade, and species of the forest understory rank higher. Our article on [what to plant under a big tree](https://bluewhaletrees.com/articles/what-to-plant-under-a-big-tree/index.html.md) covers planting without hurting the tree.

### Which native trees and shrubs grow together in the wild?

The tool lists up to eight natives that share a natural community with your species and grow wild in one of its states, by the USDA PLANTS Database. The communities are our own tags, and sharing one does not mean two species always grow side by side.

### Can eastern red cedar be planted near crabapples?

The University of Minnesota Extension says not to plant [eastern red cedar](https://bluewhaletrees.com/plants/eastern-red-cedar/index.html.md) within a few hundred yards of crabapples, hawthorns, serviceberries, chokeberries or mountain ash, since cedar-apple and related rusts live on both. The tool keeps them out of each other's answers.

The communities are our own tags. Every species we grow, with its communities, is in the [habitats table, A to Z](https://bluewhaletrees.com/articles/plant-habitats/index.html.md). The states of native range are the USDA PLANTS Database's records, read between 2026-09-23 and 2026-10-22 (2026-10-13 for the common natives we do not grow), 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, or its record for a common native we do not grow. 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 species 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.

The address carries the companion species tool's inputs, so a link opens it filled in, and Copy link on a result writes one: species (a plant's slug, the last part of its page's address, such as white-oak), zone (a whole number from 2 to 10, to keep the companions to it), sort (featured, name, price-asc, price-desc, height, hardy or fast). For example, [/tools/companions/?species=white-oak&zone=6](https://bluewhaletrees.com/tools/companions/index.html.md?species=white-oak&zone=6).