Hazel Alder (Serrulata)

The Hazel Alder (Serrulata) is generally described as a perennial tree or shrub. This is native to the U.S. (United States) has its most active growth period in the spring and summer . The greatest bloom is usually observed in the spring, with fruit and seed production starting in the summer and continuing until summer. Leaves are not retained year to year. The Hazel Alder (Serrulata) has a moderate life span relative to most other plant species and a rapid growth rate. At maturity, the typical Hazel Alder (Serrulata) will reach up to 30 feet high, with a maximum height at 20 years of 12 feet.

The Hazel Alder (Serrulata) is easily found in nurseries, garden stores and other plant dealers and distributors. It can be propagated by bare root, container, seed. It has a moderate ability to spread through seed production and the seedlings have low vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below -23°F. has low tolerance to drought and restricted water conditions.

Uses of : Landscaping, Medicinal, Culinary, etc.

Smooth alder is used predominantly for streambank stabilization and wetland restoration. It is also a critical cover component of woodcock habitat.

General Characteristics

Smooth alder is a nitrogen-fixing, thicket-forming shrub or small tree with dark, green foliage. It is a U.S. native. It is suitable for streambank stabilization because of its flexible stems and fibrous root system. A mature height of 8-12 feet may be reached in 10 years. Seed is produced in small cones with pollen contributed by birch-like catkins which bloom in mid-to late March. Compared to other alder species, smooth alder is more densely branched and produces more seed. Alders produce nitrogen for themselves by the activity of nitrogen-fixing bacteria located in root nodules. For this reason, it is not recommended for planting in areas where additional nitrogen might add to water quality problems. Smooth alder has about 400,000 seeds per pound.

Required Growing Conditions

Smooth alder is native to the northeast. It occurs from southern Maine to northern Florida, west to southeastern Oklahoma, Missouri, and Illinois. It grows best in wet bottomlands and stream margins, however it will also grow in well-drained upland areas. It is moderately shade and acid tolerant, but is weak-wooded and susceptible to wind and ice damage.

Cultivation and Care

For streambank stabilization, smooth alder is best established as a bare-root or containerized seedling planted two feet apart within rows with rows two feet apart. It may be incorporated into a soil bioengineering system by planting at the toe of the bank just above any toe stabilization measures such as rip-rap, coir (coconut) logs, or fascines. On non-erosive streambanks it may be planted in two rows to provide toe protection. If this alder is planted for wildlife habitat improvement or wetland mitigation, planting should be done at a 5-10 foot spacing to allow for crown development and to optimize seed production.

General Upkeep and Control

Very little maintenance is needed except replacing dead plants and keeping debris from inhibiting growth.

Cultivars, Improved, and Selected Materials (and area of origin) At present only common smooth alder is available from commercial and state nurseries.

Plant Basics
Growth Rate Rapid
General Type Tree, Shrub
Growth Period Spring, Summer
Growth Duration Perennial
Lifespan Moderate
Plant Nativity Native to U.S.
Commercial Availability Routinely Available
Physical Characteristics
Bloom Period Spring
Displays Fall Colors No
Shape/Growth Form Multiple Stem
Drought Tolerance Low
Shade Tolerance Intolerant
Height When Mature 30
Vegetative Spread Slow
Flower Conspicuousness No
Fruit/Seed Abundance Low
Fruit/Seed Seasonality Summer Summer
Seed Spread Rate Moderate
Gardening Characteristics
Propagations (Ways to Grow) Bare Root, Container, Seed
Moisture Requirements High
Cold Stratification Required Yes
Minimum Temperature -23
Soil Depth for Roots 24
Toxic to Nearby Plants No
Toxic to Livestock No
After-Harvest Resprout Ability No
Responds to Coppicing No
Growth Requirements
pH Range 5–7 pH
Precipitation Range 32–32 inches/yr
Planting Density 1200–2700 indiv./acre
Soil Textures Coarse, Fine, Medium
Soil Depth for Roots 24
Minimum Frost-Free Days 120 day(s)
Salinity Tolerance None
CaCO3 Tolerance Low
Sustainability & Use
Leaf Retention No
Palatability Medium
Fire Resistant No

Source: USDA, NRCS, PLANTS Database, plants.usda.gov.
National Plant Data Center, Baton Rouge, LA 70874-4490 USA