Alstonia spectabilis
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Alstonia spectabilis

Hard alstonia · Hard cheesewood · Hard milkwood · Milky yellowwood

Tier 2 Difficulty: easy Water: low Light: partial_sun
Temperature
20–35 °C
Soil pH
6–7
Hardiness
Zone 9–9
0
Observations
1

Description

Source: wikipedia (CC BY-SA)

Alstonia spectabilis, commonly known as bitterbark, yellowjacket, milky yellowwood, leatherjacket, jackapple, hard milkwood or hard cheesewood, is a medium-sized species of tree in the dogbane family. It is native to eastern Malesia, Melanesia and northern Australia.

🌳 Blackboard tree has attracted attention for its potential as a natural air purifier. Because of its large leaf canopy and ability to absorb pollutants, it is incorporated into urban greening projects designed to reduce environmental pollution. The blackboard tree's versatile uses beyond timber and traditional medicine make it a candidate for tackling rising air pollution in congested cities, presenting it as an eco-friendly asset.

Care Guide

💧 Water
☀️ Light Partial sun

Blackboard tree needs a location with abundant sunlight to develop vigorously. Native to a region with intense sun and heat, it does very well under those conditions. Excessive shade inhibits its growth, while ample sunshine increases its vigor; however, too much exposure can result in sunscald.

Ideal: Partial sun
🌡️ Temperature 20–35°C

The Blackboard tree is indigenous to areas where temperatures typically range from 68 to 95°F (20 to 35°C). It prefers warmer climates with steady temperatures. If located in colder regions, consider providing warm shelter or indoor care during the harsh winter months.

Ideal temperature: 20–35°C
💨 Humidity
Humidity:
🪴 Soil 6-7
Soil pH: 6-7
🌱 Fertilizer

The timing of fertilizing a Blackboard tree is important. Apply fertilizer in early spring and continue monthly until early summer. Fertilizer encourages attractive blooms and supplies energy during both dormant and active growth phases.

🪴 Pot & Repot 2-3 years

When repotting a Blackboard tree, select a pot 1-2 inches (2.5–5.1 cm) larger that offers good drainage. Use a well-draining potting mix. Repot in spring or fall, making sure the root ball sits slightly below the rim of the pot. Water thoroughly after repotting and place the plant in a warm spot with indirect sunlight.

Suggested frequency: 2-3 years
✂️ Pruning
🌿 Propagating
🐛 Diseases & pets
☠️ Toxicity

Characteristics

Plant Type
Tree
Life Cycle
Perennial
Genus
Alstonia
Family
Apocynaceae
Hardiness Zone
9
Mature Height
20.12 m
Mature Spread
3.35 m
Leaf Color
Green
Leaf Type
Evergreen, Semi-evergreen
Flower Color
White, Cream
Flower Size
0.51 cm to 1.02 cm
Bloom Time
Early spring, Mid spring, Late summer, Fall, Winter
Planting Time
Spring, Autumn
Harvest Time
Late spring, Early summer, Mid summer
Native Area
Nepal, Sri Lanka, India, Malaysia, Philippines, Bangladesh, Laos, Brunei, China, Indonesia, Cambodia, Vietnam, Myanmar, Bhutan, Thailand

Tags (5)

Common Names (4)

en Hard alstonia
en Hard cheesewood
en Hard milkwood
en Milky yellowwood