• Photo of Alnus japonica (Alnus japonicas)

Plant Profile: Alnus japonica

Taxonomy: Alnus japonica

Names

Japanese Alder

  • Photo of Alnus japonica (Alnus japonicas)

Phonetic Spelling:AL-nus juh-PON-ih-kuh

Genus:Alnus

Species:japonica

Family:Betulaceae

This resilient and versatile plant faces minimal pest issues and can withstand brief periods of flooding. It thrives in full sunlight, producing its best flowers and fruits under these conditions. While it is relatively rare in the United States, it is an excellent choice for challenging environments, including wet low-lying areas or dry locations with subpar soil. It is commonly found in woodland settings but struggles to thrive in regions south of zone 7.

Regarding pests and diseases, this plant does not encounter any significant challenges.

Alnus japonica Feature Summary

Alnus japonica Image Gallery

Tags

#deciduous
#shade tree
#conical
#spotted
#wet sites
#moist soil
#adaptable
#pryamidal
#dry soils tolerant
#woodlands

Similar Plants

Alnus japonica Feature Summary

Attributes
Japan, Korea, Manchuria
Fruit
ellipsoidal fruiting cones 3/4"-1" long
Flowers
Monecious blooms appear in March yellow-brown to red-brown catkins (male flowers) appear in clusters, female flowers on short, purplish-brown strobili which persist until winter
Purple/Lavender
Gold/Yellow
Brown/Copper
Insignificant
Leaves
Oval, narrow leaves acuminate, serrulate, dark green leaves (to 5" long). Wedge-shaped at the base and light green underneath. Fall color unremarkable.
Elliptical
Ovate
3-6 inches
Cultural Conditions
Full sun (6 or more hours of direct sunlight a day)
Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Frequent Standing Water
12-24 feet
6-feet-12 feet
Landscape
Shade Tree
Insect Pests
Wet Soil
Dry Soil
Poor Soil
Woodland
Slope/Bank

Alnus japonica Attributes

Alnus japonica: Country Or Region Of Origin

Japan, Korea, Manchuria

Alnus japonica: Life Cycle

Annual
Biennial
Bulb
Perennial
Woody

Alnus japonica Fruit

Alnus japonica: Fruit Description

ellipsoidal fruiting cones 3/4"-1" long

Alnus japonica: Fruit Type

Achene
Aggregate
Berry
Capsule
Caryopsis
Drupe
Follicle
Legume
Nut
Pome
Samara
Schizocarp
Siliqua

Alnus japonica: Fruit Length

< 1 inch
1-3 inches
> 3 inches

Alnus japonica Flowers

Alnus japonica: Flower Description

Monecious blooms appear in March yellow-brown to red-brown catkins (male flowers) appear in clusters, female flowers on short, purplish-brown strobili which persist until winter

Alnus japonica: Flower Color

filter_vintage
Brown/Copper
filter_vintage
Gold/Yellow
filter_vintage
Insignificant
filter_vintage
Purple/Lavender

Alnus japonica: Flower Inflorescence

Catkin
Corymb
Cyme
Head
Insignificant
Panicle
Raceme
Solitary
Spadix
Spike
Umbel

Alnus japonica: Flower Bloom Time

Winter
Spring
Summer
Fall

Alnus japonica Leaves

Alnus japonica: Leaf Description

Oval, narrow leaves acuminate, serrulate, dark green leaves (to 5" long). Wedge-shaped at the base and light green underneath. Fall color unremarkable.

Alnus japonica: Woody Plant Leaf Characteristics

Broadleaf Evergreen
Deciduous
Needled Evergreen
Semi-evergreen

Alnus japonica: Leaf Color

spa
Green

Alnus japonica: Leaf Shape

Acicular
Auriculate
Cordate
Cuneate
Deltoid
Elliptical
Filiform
Lanceolate
Linear
Oblanceolate
Oblong
Obovate
Obtuse
Orbicular
Ovate
Palmasect
Palmatifid
Peltate
Pinnatifid
Pinnatisect
Reniform
Rhomboidal
Spatulate
Subcordate
Subulate

Alnus japonica: Leaf Margin

Crenate
Crenulate
Dentate
Denticulate
Doubly Crenate
Doubly Dentate
Doubly Serrate
Entire
Lobed
Serrate
Sinuate
Undulate

Alnus japonica: Hairs Present

No
Yes

Alnus japonica: Leaf Length

< 1 inch
1-3 inches
3-6 inches
> 6 inches

Alnus japonica Whole Plant Traits

Alnus japonica: Plant Type

Annual
Bulb
Carnivorous
Edible
Epiphyte
Fern
Ground Cover
Herb
Herbaceous Perennial
Houseplant
Mushroom
Native Plant
Ornamental Grasses and Sedges
Perennial
Poisonous
Rose
Shrub
Succulent
Tree
Turfgrass
Vegetable
Vine
Water Plant
Weed
Wildflower

Alnus japonica: Woody Plant Leaf Characteristics

Broadleaf Evergreen
Deciduous
Needled Evergreen
Semi-evergreen

Alnus japonica: Habit/Form

Arching
Ascending
Broad
Cascading
Climbing
Clumping
Columnar
Conical
Creeping
Dense
Erect
Horizontal
Irregular
Mounding
Multi-stemmed
Multi-trunked
Open
Oval
Prostrate
Pyramidal
Rounded
Spreading
Vase
Weeping

Alnus japonica: Maintenance

Low
Medium
High

Alnus japonica: Texture

Fine
Medium
Coarse

Alnus japonica Cultural Conditions

Alnus japonica: Light

Dappled Sunlight (Shade through upper canopy all day)
Deep shade (Less than 2 hours to no direct sunlight)
Full sun (6 or more hours of direct sunlight a day)
Partial Shade (Direct sunlight only part of the day, 2-6 hours)

Alnus japonica: Soil Drainage

Frequent Standing Water
Good Drainage
Moist
Occasional Flooding
Occasionally Dry
Occasionally Wet
Very Dry

Alnus japonica: Available Space To Plant

12 inches-3 feet
12-24 feet
24-60 feet
3 feet-6 feet
6-feet-12 feet
Less than 12 inches
more than 60 feet

Alnus japonica: USDA Plant Hardiness Zone

thermostat
5a
thermostat
5b
thermostat
6a
thermostat
6b
thermostat
7a
thermostat
7b

Alnus japonica Stem

Alnus japonica: Stem Is Aromatic

No
Yes

Alnus japonica Landscape

Alnus japonica: Design Feature

Accent
Barrier
Border
Flowering Tree
Foundation Planting
Hedge
Mass Planting
Screen/Privacy
Security
Shade Tree
Small groups
Small Tree
Specimen
Street Tree
Understory Tree

Alnus japonica: Resistance To Challenges

Black Walnut
Compaction
Deer
Diseases
Drought
Dry Soil
Erosion
Fire
Foot Traffic
Heat
Heavy Shade
Humidity
Insect Pests
Pollution
Poor Soil
Rabbits
Salt
Slugs
Squirrels
Storm damage
Urban Conditions
Voles
Wet Soil
Wind

Alnus japonica: Landscape Location

Coastal
Container
Hanging Baskets
Houseplants
Lawn
Meadow
Naturalized Area
Near Septic
Patio
Pond
Pool/Hardscape
Recreational Play Area
Riparian
Rock Wall
Slope/Bank
Small Space
Vertical Spaces
Walkways
Woodland