Tree of heaven (Ailanthus altissima)

Also known as: Chinese Sumac, Paradise tree, Tree of hell, Varnish tree

Despite its pleasant name, the tree of heaven is notorious in numerous parts of the US for its invasive nature. Many states classify it as an invasive species due to its aggressive spread, prolific seed production, and resilience in poor soil conditions. Its robust root system often causes damage to sidewalks, sewers, and other infrastructure.

In This Article

Care Tips Water Sunlight Temperature Soil Fertilize Prune Propagation Repotting Toxicity

Attributes of Tree of heaven

Lifespan

Perennial

Plant Type

Tree

Plant Height

10 m to 27 m

Spread

15 m

Leaf Color

Green Red

Flower Size

2.5 cm

Flower Color

Green Yellow

Images of Tree of heaven

Quickly Identify Tree of heaven

Large compound leaves, 10-41 lanceolate leaflets, 1-4 feet (30-120 cm) long.

Smooth pale gray bark, becoming rough and furrowed with age.

Yellow-green flowers in panicles, emitting a foul odor.

Distinctive samaras with twisted papery wings, up to 2 inches (5 cm) long.

Light chestnut brown stem emitting foul odor when broken, thin twigs, zigzag branching.

Scientific Classification of Tree of heaven

Phylum

Vascular plants

Class

Dicotyledons

Order

Maples, mangos, mahogany, citrus, and allies

Family

Quassia

Genus

Ailanthus

Species

Tree of heaven

Planting and Growing of Tree of heaven

Care Difficulty

Easy

Watering Schedule

Every 2 days

Sunlight Requirements

Full sun

Sunshine Duration

6-10 hours

Ideal Temperature

60-85℉

Soil Type

Potting Mix, Peat Mix

Soil pH

6-8

Fertilizer Type

Balanced

Pruning Season

Spring, Summer

Pruning Area

Branches, Leaves

Pruning Frequency

2 times a year

Repotting Season

Spring

Pot Type

Plastic, Ceramic

How to Water Tree of heaven?

Ailanthus altissima, known as the Tree of Heaven, requires a moderate amount of water each time you water it. Ensure that the soil is thoroughly moist but not soggy, aiming for around 500 ml per session. The key is to keep a consistent level of moisture in the soil without water logging it.

What are the symptoms of an underwatered Tree of heaven? ›

What should I do if my Tree of heaven is not getting enough water? ›

What are the symptoms of an overwatered Tree of heaven? ›

How to save an overwatered Tree of heaven? ›

What Are the Sunlight Requirements for Tree of heaven?

Sunlight Requirements: Full sun, Partial sun

Duration of light: 6-8 hours per day

Ideally, Ailanthus altissima should be exposed to full sun for 6-8 hours daily. This lighting fosters healthy growth and robustness against environmental challenges.

What is the recommended lighting condition for Ailanthus altissima? ›

How can I achieve optimal lighting for Ailanthus altissima? ›

What are the benefits of providing optimal lighting to this plant? ›

What Is the Ideal Temperature Range for Tree of heaven?

Ideal Temperature: 60 ~ 85℉

The ideal temperature range for growing Ailanthus altissima is between 60°F and 85°F. Within this range, the tree can thrive and exhibit optimal growth. The moderate warmth ensures efficient photosynthesis and healthy foliage, allowing the plant to develop robust roots and branches. Maintaining this temperature range is crucial for achieving best results.

What Soil is Best for Tree of heaven?

Soil type: Sandy loam, Loam, Calcareous soil

Soil PH: 6 ~ 8

Ailanthus altissima thrives well in nutrient-rich soils, as they provide essential minerals and nutrients required for its rapid growth. Ensuring the soil is well-fertilized can help maintain the plant's health and vigor, allowing it to establish quickly and outgrow competitors. Having well-drained soil is critical for preventing root rot and other water-related issues in Ailanthus altissima. It ensures that water does not accumulate around the roots, which could otherwise lead to decomposition and disease, benefiting the plant by keeping the root zone healthy and aerated. Although they prefer well-drained soils, Ailanthus altissima also benefits from soils that can retain moisture to some degree. This ability ensures the plant has consistent water access during dry periods, promoting continuous growth and resilience.

How to Fertilize Tree of heaven?

Fertilizer type: Balanced

Ailanthus altissima does not require heavy fertilization. Apply a balanced liquid fertilizer at half the recommended strength once a month during the growing season. Over-fertilizing can lead to excessive growth and stress.

How to Prune Tree of heaven?

Pruning Time: Spring, Summer, Autumn, Winter

Start by removing any dead, diseased, or damaged branches. Look for branches that cross each other or grow inward, as these can hinder the tree’s growth and air circulation. Ailanthus altissima can grow quite large, so it's important to manage its size. Trim back branches to shape the tree, focusing on maintaining a balance between growth and control. This involves cutting back overreaching branches to their base or a lateral bud. Trim the inner branches of the tree to allow more sunlight and air to penetrate its canopy. This not only benefits the tree’s health by reducing the risk of fungal issues but also promotes new growth around the tree. Due to its rapid growth, Ailanthus altissima requires regular pruning to prevent it from becoming unruly. Check the tree monthly and remove any new unwanted shoots or suckers from the base to prevent spreading.

How to Propagate Tree of heaven plant?

Propagate Time: Spring,Early summer

Collect seeds in autumn, stratify them by storing in a refrigerator for 2-3 months. Sow them in spring in well-draining soil, keeping them moist until germination occurs.

Select a healthy parent plant. In early summer, dig around the plant to find suitable roots. Cut 3-4 inch sections, leaving at least one node with visible buds.

Plant root cuttings horizontally in sandy soil, with nodes barely exposed. Water lightly, avoiding overwatering to prevent rot, and ensure they are kept warm and at consistent moisture levels.

How to Repot Tree of heaven plant?

Repotting frequency: Every two years

Ailanthus altissima thrives when its roots have ample space to expand. Look for signs such as roots circling the pot's bottom, reduced growth, or diminished water uptake. Spring provides the best conditions for recovery and growth after repotting.

Opt for a pot 2-3 inches wider in diameter to allow root expansion. Ensure the pot has adequate drainage holes to prevent waterlogging, which can lead to root rot. The right pot encourages healthy root development and vigorous growth.

Choose a well-draining, loamy soil that mimics the plant's natural habitat. This type of soil prevents root rot while providing necessary nutrients. It supports optimal growth and keeps the plant healthy.

Toxicity of Tree of heaven

Is Tree of heaven toxic to cat?

The tree of heaven is recognized as a poisonous plant for cats, particularly hazardous due to its leaves and flowers. Cats may unintentionally consume these components, resulting in symptoms of physical unease or sickness that require urgent veterinary attention. If a cat is believed to have ingested tree of heaven and is showing signs of poisoning, it is crucial to obtain immediate veterinary care to mitigate possible health issues. Preventing cats from accessing tree of heaven is vital in avoiding accidental poisoning and protecting their health.

Is Tree of heaven toxic to dog?

The tree of heaven is a hazardous plant for dogs, representing serious health threats if consumed. Dogs may inadvertently ingest various parts of this plant, leading to the risk of poisoning. The leaves and flowers in particular are extremely harmful and must be secured away from pets. If a dog happens to consume any portion of the tree of heaven, they might display symptoms like vomiting, diarrhea, weakness, or abdominal discomfort. It is essential for dog owners to keep a vigilant watch over their pets and to restrict their access to the tree of heaven. Should a dog ingest this plant, swift veterinary intervention is crucial to effectively address the poisoning.

WARNING

The judgment on toxicity and danger is for reference only. We DO NOT GUARANTEE any accuracy of such judgment. Therefore, you SHALL NOT rely on such judgment. It is IMPORTANT TO SEEK PROFESSIONAL ADVICE in advance when necessary.