American Elm
Ulmus americana Large tree Zones 2–9 60–80 ft
Shares floodplain forests, stream banks, swamps and wet flats in the wild.
A native we do not grow
Red Alder
Alnus rubra. Large tree, 40 to 98 feet where planted, zones 5 to 8; full sun; dry, average or wet ground.
We do not grow red alder, and it is not in our shop. This page gathers what our tools say about it and the natives we grow for the same ground.
At a glance
| Other names | Oregon alder, western alder, Pacific Coast alder |
|---|---|
| Form | Large tree |
| Height, feet | 40 to 98 where planted; up to 130 in its native stands |
| Spread, feet | Up to 50 |
| Zones | 5 to 8 |
| Sun | Full sun |
| Soil moisture | Dry, average or wet ground |
| Growth | Fast |
| Leaves | Deciduous |
| Traits | Wildlife value, hedge or screen, nitrogen fixing, erosion control |
| Flowers | February to May |
| Fruit | Cones, August to February |
| First crop | 3 to 4 years (most trees in a stand 6 to 8) |
| Pollination | One bears; a second improves the crop. Male and female catkins grow on the same tree. Most seed comes from crossing between trees, though a lone tree sets some from its own pollen. |
| Lifespan | Lives up to 100 years. |
| Planting season | Spring. The NRCS plant guide sets seedlings out in summer if they are big enough, otherwise the following spring. |
| Black walnut | Not named on the Morton Arboretum's lists |
| Ground | Floodplain forests, stream banks, the coast, swamps and wet flats |
| Native in | 6 states |
Red alder is native in 6 states: Alaska, California, Idaho, Montana, Oregon and Washington. The states are the USDA PLANTS Database's records, with the native range read from Silvics of North America, the Fire Effects Information System, the NRCS plant guide and NC State Extension.
What our tools say
How fast it grows and how big it gets, by site Whether it suits your zone, sun and soil How far from a house, wires and a septic field What grows with it in the wild and in a yard When to plant it where you live When it flowers and fruits, month by month How to sow its seed, with dates for your place How many to plant for a crop of seed Whether one you have can be moved, and what the move takes How old one is, from its trunk How a big one scores against the champion trees
For the same ground, we grow
These trees we grow share the most of red alder's natural communities in the wild, by the companion species tool's rules.
Balsam Poplar
Populus balsamifera Large tree Zones 2–5 30–100 ft
Shares floodplain forests, stream banks, swamps and wet flats in the wild.
Peachleaf Willow
Salix amygdaloides Medium tree Zones 2–8 35–60 ft
Shares floodplain forests, stream banks, swamps and wet flats in the wild.
Tamarack
Larix laricina Large tree Zones 2–6 50–75 ft
Shares stream banks, swamps and wet flats in the wild.
Read from
Its figures come from Silvics of North America, the Forest Service's Fire Effects Information System, the Woody Plant Seed Manual, the USDA PLANTS Database, Oregon State University's Landscape Plants, Cal Poly's SelecTree, NC State Extension, the Wildflower Center and Calscape.