Invasive Shade-Tolerant Garden Plants in Hawaii

Hawaii’s rich ecosystems, from lush rainforests to tropical woodlands, are particularly susceptible to invasive plants that thrive in shaded environments. These plants, often introduced for their ornamental appeal, can spread quickly and disrupt the delicate balance of Hawaii's native habitats. Understanding these invasive species and opting for native alternatives is crucial for preserving Hawaii’s unique natural beauty and ecological diversity.

Golden Crownbeard (Verbesina encelioides)

List of Invasive Shade-Tolerant Garden Plants in Hawaii

1. Strawberry Guava (Psidium cattleianum)

• Description: Strawberry Guava is a small tree or shrub with evergreen leaves, pink to red fruits, and white flowers. It is commonly planted for its fruit and ornamental value.

• Impact: Spreads rapidly, forming dense thickets that outcompete native plants and disrupt forest ecosystems in shaded areas.

• Garden Alternative: Ohi’a Lehua (Metrosideros polymorpha) - A native tree with vibrant red flowers and ecological importance, supporting local wildlife and thriving in shade.

2. Miconia (Miconia calvescens)

• Description: Miconia is a large shrub or small tree with broad, dark green leaves and clusters of small, pink flowers. It is used for its ornamental foliage and rapid growth.

• Impact: Forms dense stands that smother native vegetation and alter soil conditions, significantly impacting Hawaii’s forest ecosystems.

• Garden Alternative: Hala (Pandanus tectorius) - A native plant with unique, spiky leaves and fruit, providing habitat for wildlife and thriving in shaded conditions.

3. Clidemia (Clidemia hirta)

• Description: Clidemia is a shrub with large, glossy leaves and white to pink flowers. It’s often used as ground cover or for ornamental purposes.

• Impact: Spreads aggressively, forming dense mats that smother native plants and reduce biodiversity in shaded areas.

• Garden Alternative: Alahe’e (Psydrax odorata) - A native shrub with fragrant flowers and dense foliage, supporting local wildlife and maintaining ecological balance.

4. Java Plum (Syzygium cumini)

• Description: Java Plum is a fast-growing tree with dark green leaves and purple-black fruits. It is used for its ornamental and fruiting characteristics.

• Impact: Spreads rapidly and displaces native plants, altering local ecosystems and impacting forest health.

• Garden Alternative: Koa (Acacia koa) - A native tree with valuable wood and ecological benefits, supporting native flora and fauna in shaded areas.

5. Hairy Brush (Trichosanthes cucumerina)

• Description: Hairy Brush is a vigorous vine with large, lobed leaves and white flowers. It is used for its rapid growth and ornamental value.

• Impact: Spreads aggressively, covering and smothering native vegetation, leading to reduced biodiversity in shaded environments.

• Garden Alternative: Hibiscus (Hibiscus rosa-sinensis) - A native plant with large, colorful flowers and a more controlled growth habit suitable for shaded gardens.

6. Golden Crownbeard (Verbesina encelioides)

• Description: Golden Crownbeard is a shrub with bright yellow flowers and sprawling foliage. It is often used for its ornamental value and rapid growth.

• Impact: Forms dense stands that can displace native plants and alter soil conditions, affecting local ecosystems.

• Garden Alternative: Kahili Ginger (Hedychium gardnerianum) - A native ginger with fragrant flowers that supports pollinators and thrives in shaded areas.

7. Wild Ginger (Zingiber zerumbet)

• Description: Wild Ginger is a tropical plant with large, glossy leaves and fragrant white flowers. It is used for its ornamental value and attractive foliage.

• Impact: Can spread quickly and outcompete native vegetation, altering local habitats and reducing biodiversity.

• Garden Alternative: ʻŌhiʻa Lehua (Metrosideros polymorpha) - A native plant with vibrant flowers and ecological importance, supporting local wildlife and thriving in shaded conditions.

8. Chinese Tallow Tree (Triadica sebifera)

• Description: Chinese Tallow Tree is a deciduous tree with heart-shaped leaves and white fruits that turn into glossy, black seeds. It is used for its ornamental appeal and rapid growth.

• Impact: Spreads quickly and forms dense stands, displacing native vegetation and altering soil conditions.

• Garden Alternative: Pū hala (Pandanus tectorius) - A native tree with unique foliage and fruit, providing shade and habitat without being invasive.

9. Noni (Morinda citrifolia)

• Description: Noni is a small tree or shrub with broad, glossy leaves and knobby, yellowish fruits. It’s often used for its fruit and medicinal properties.

• Impact: Spreads aggressively and can outcompete native plants, disrupting local ecosystems and reducing biodiversity.

• Garden Alternative: ʻŌhiʻa Lehua (Metrosideros polymorpha) - A native plant with vibrant flowers and ecological importance, supporting local wildlife.

Conclusion

Invasive shade-tolerant plants pose a significant threat to Hawaii’s unique ecosystems by outcompeting native species and altering local habitats. By opting for native, non-invasive alternatives, gardeners can help protect Hawaii’s natural beauty, support local wildlife, and contribute to ecological balance.

For more information and to connect with other gardening enthusiasts, join our Facebook group: Shade Gardening.