Alnus firma
Images by part: leaf (3) · flower (0) · fruit (1) · bark (0) · habit (0) · other (0)

Alnus firma

Japanese green alder

Tier 1 Difficulty: easy Water: low Light: full_sun
Temperature
5–32 °C
Soil pH
6–7
Hardiness
Zone 5–8
Click count
1
Observations
7

Description

Source: leafsnap

Alnus firma is a species of Alnus from Japan.

Care Guide

💧 Water
☀️ Light Full sun

Alnus firma is native to open habitats, including sunlit meadows and forest edges that provide abundant light. It performs best in Full Sun but can tolerate Partial Sun, adapting readily to a range of light conditions.

Ideal: Full sun
FAQ
What are the sunlight requirements for Alnus firma?

Alnus firma, also known by its botanic name Alnus firma, thrives in conditions where it can receive a specific amount of sunlight throughout the day. For optimal growth, this plant requires full sun, characterized by receiving above 6 hours of sunlight daily. Alternatively, it can also adapt to partial sun, where it gets about 3-6 hours of sunlight. It's important to observe the movement of sunlight in your garden to identify spots that offer a harmonious balance of light and shade. Selecting the right location ensures the plant's health and happiness, aligning with its natural needs for light.

🌡️ Temperature 5–32.2°C

Alnus firma is highly adaptable to a range of climate conditions, from very hot summers to cold winters. That said, it has a preferred temperature range for growth. If temperatures become too high, the plant can experience stress from extreme heat and humidity, which may lead to its death. In locations where temperatures approach the lower edge of its cold tolerance, insulating measures should be used to protect the plant.

Ideal temperature: 5–32.2°C
💨 Humidity
Humidity:
🪴 Soil 6-7
Soil pH: 6-7
🌱 Fertilizer

Fertilize your Alnus firma in early spring to encourage healthy growth. Regular feeding improves overall health, producing vigorous growth, increased tolerance of harsh conditions, and enhanced resistance to pests and diseases. Keep a consistent fertilization schedule for your Alnus firma to maintain foliage that is vibrant with rich color and a lush appearance.

🪴 Pot & Repot
✂️ Pruning

Alnus firma is a deciduous tree known for its unique catkins and toothed leaves. To maintain its health, prune it in early spring by removing any dead or damaged branches. Light shaping can help improve the tree's structure, but be cautious, as heavy pruning may stress the plant. Always use clean, sharp tools to minimize the risk of disease.

🌿 Propagating
🐛 Diseases & pets
☠️ Toxicity

Characteristics

Plant Type
Tree
Life Cycle
Perennial
Genus
Alnus
Family
Betulaceae
Hardiness Zone
5-8
Mature Height
14.94 m to 20.12 m
Mature Spread
7.92 m to 11.89 m
Leaf Color
Dark Green, Forest Green
Leaf Type
Deciduous
Flower Size
2.03 cm to 3.05 cm
Bloom Time
Late winter, Early spring
Planting Time
Spring, Autumn
Harvest Time
Late summer, Early fall, Mid fall
Native Area
Japan

Tags (5)

Common Names (1)

en Japanese green alder