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| ## thinleaf alder {#thinleaf-alder .Title-Header}                     |
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| *Alnus incana* (L.) Moench.                                           |
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| Plant Symbol = ALIN2                                                  |
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##### *Contributed By: USDA NRCS National Plant Data Center*

# Alternate Names

Thin-leafed alder, grey alder, mountain alder, river alder

# Uses

*Ethnobotanic*: Native Americans reportedly pounded the wood of thin
leaf alder into a powder to produce a red dye (Lanner 1983). The wood
was occasionally used for firewood. It is also valued by cabinetmakers
and is used in making clogs, bowls, and woodcuts.

*Wildlife*: Cottontails, muskrats, moose, elk, deer, and snowshoe hares
eat the leaves and twigs. Redpolls, siskins, chickadees, and goldfinches
eat alder seeds, buds, and catkins. Beavers eat the bark and build dams
with the stems.

*Agroforestry*: *Alnus incana* is an excellent pioneer species for
revegatating disturbed riparian areas or as a mass planting to achieve a
screen or windbreak. Thin-leaf alder is used in tree strips for
windbreaks, which are planted and managed to protect livestock, enhance
production, and control soil erosion. Windbreaks can help communities
with harsh winter conditions better handle the impact of winter storms
and reduce home heating costs during the winter months.

# Status

# Please consult the Plants Web site and your State Department of Natural Resources for this plant's current status, such as, state noxious status and wetland indicator values. 

# Description

*General:* Thin-leafed alder is a native, deciduous shrub or tree. The
leaves are ovate, double serrated, and pointed at the tip. Male catkins
are produced in the autumn in-groups of three or four. The female
catkins are borne separately on the same plant in late winter or early
spring. The fruit are small, brown, scale-like cones produced in early
autumn. The bark is thin, smooth, and green-gray, grayish-brown, or
reddish-brown (Preston 1948).

*Distribution*: Thin-leaf alder is distributed throughout Europe and
much of North America. For current distribution, please consult the
Plant profile page for this species on the PLANTS Web site.

# 

# Adaptation

This shrub or small tree tolerates a wide range of soil types. It grows
best in heavy moist soils in light shaded areas. It has a high flood
tolerance and typically grows near rivers and moist stream borders on
poorly developed soil. Thin-leaf alder is frequently found growing in
the understory of coniferous forests on moist sites. It is also
adaptable to a range of soil pH levels.

# Establishment

*Propagation from Seed*: Seed is best sown as soon as it is ripe in a
cold frame. If *Alnus incana* seeds are not sown in the fall, they
require cold stratification for three months before germination. Sow the
seeds in containers or seed trays containing a slow release fertilizer.
Firm the medium and place the seeds thinly and evenly on top. When large
enough to handle, the seeds can be placed into individual pots. If
growth is sufficient, they may be planted into their permanent positions
in the summer, if not they can be planted in the spring.

# Management

Thin-leaf alder often occurs in dense thickets, which reportedly results
from underground rhizomes or suckers (Dayton 1931). If plants are
damaged, sprouting can occur from the stump, root collar, or from the
root crown following fire. After top-removal of plants by beavers, they
have been observed to sprout heavily from the cut.

Propagation from cuttings is not recommended and plants are not widely
available in nurseries.

# Cultivars, Improved and Selected Materials (and area of origin)

Somewhat available through native plant nurseries within it range.

## 

# References

Arno, S.F. 1977. *Northwest trees*. The Mountaineers, Seattle,
Washington.

Coombes, A.J. 1992. *Eyewitness handbooks: trees*. Dorling Kindersley,
Inc., New York, New York.

Davis, Brian. 1987. *The gardener's illustrated encyclopedia of trees
and shrubs*. Rodale Press, Inc., Emmaus, Pennsylvania.

Dayton, W.A. 1931. *Important western browse plants*. Misc. Publication
101. Washington, D.C.

Dirr, M.A. 1990. *Manual of woody landscape plants: their
identification, ornamental characteristics, culture, propagation, and
uses*. 4^th^ ed. Stipes Publishing Company, Champaign, Illinois.

Dirr, M.A. & C.W. Heuser 1987. *The reference manual of woody plant
propagation: from seed to tissue culture*. Varsity Press, Athens,
Georgia.

Epple, A.O. 1995. *A field guide to the plants of Arizona*. Falcon
Press, Helena, Montana.

Haeussler, S & D. Coates 1986. *Autecological characteristics of
selected species that compete in British Columbia: a literature review*.
Land Management Report No. 33. Victoria, BC.

Heuser, C.W. 1997. *The complete book of plant propagation*. The Taunton
Press, Newtown, Connecticut.

Lanner, R.M. 1983. *Trees of the Great Basin: a natural history*.
University of Nevada Press, Reno, Nevada.

Martin, A.C.; H.S. Zim & A.L. Nelson 1951. *American wildlife and
plants*. McGraw-Hill Book Company, Inc., New York, New York.

McMinn, H.E. 1939. *An illustrated manual of California shrubs*.
University of California Press, Berkeley, Los Angeles, & London.

Nelson, R.A. 1992. *Handbook of Rocky Mountain plants*. Roberts Rinehart
Publishers, Newot, Colorado.

Preston, R.J., Jr. 1948. *North American trees.* The Iowa State College
Press, Ames, Iowa.

U.S. Department of Agriculture, Forest Service. 1937. *Range plant
handbook*. Washington, DC.

# Prepared By

#### *Jammie Favorite*

Formerly USDA, NRCS, National Plant Data Center

Baton Rouge, Louisiana

# Species Coordinator

*M. Kat Anderson*

USDA, NRCS, National Plant Data Center, c/o Plant Science Dept., Davis,
California

Edited: 29jan03 jsp; 09jun03 ahv; 30may06jsp

For more information about this and other plants, please contact your
local NRCS field office or Conservation District, and visit the PLANTS
Web site\<[http://plants.usda.gov](http://plants.usda.gov/)\> or the
Plant Materials Program Web site
\<[http://Plant-Materials.nrcs.usda.gov](http://Plant-Materials.nrcs.usda.gov/)\>

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