A rain garden is a landscaped area that is designed to capture and absorb rainwater runoff from hard surfaces like driveways, roofs, and walkways. Rain gardens can vary in size and can be an effective way to reduce the amount of polluted runoff entering our waterways. Soil microorganisms and plant roots capture and break down pollutants, while the now cleaned water soaks further into the water table below instead of washing down the storm drain system and carrying dirt and pollution to our ocean. In partnership with the City and County of Honolulu, MM installed and actively maintains a rain garden at Koko Head District Park hosting volunteer workdays once a month. To participate in an upcoming rain garden workday, please email lbailes@malamamaunalua.org for more details and to RSVP.
Photo Credit: Buddy Morris
Our rain garden benefits Maunalua Bay by…
1) Reducing flooding by absorbing rainwater from hard surfaces such as roofs, parking lots, and roads.
2) Preventing the pollution of streams and nearshore waters by filtering out oil, grease, and other toxic materials.
3) Recharging groundwater aquifers by allowing water to soak into the ground instead of being directed into the storm drains and washed out to sea.
Rain Garden Plants
ʻAʻaliʻi
(Dodonaea viscosa)
ʻAhuʻawa
(Cyperus javanicus)
Alaheʻe
(Psydrax odoratum)
A’aliʻi is a versatile plant native to Hawaiʻi that can be found from sea level to high elevation of all the Hawaiian islands. The plant can be used as a specimen plant, hedge, or wind block. ʻAʻaliʻi is drought-tolerant, deeply tap-rooted, and historically used for medicinal purposes, tool-making, dye, and fishing bait. It’s fruit is used to create beautiful lei and floral arrangements.
ʻAhuʻawa is a sedge plant found in tropical Africa, Asia, and Hawaiʻi except for Kahoʻolawe. They typically grow in marshes, rocky coastal areas, and near streams, and its fibrous roots make it an effective plant for controlling erosion. The ancient Hawaiian’s utilized the plant’s pounded and dried stems to create fibers to strain pulp out of coconut and ʻawa. They prefer moist soil and full sun and can be found in marshes, streams, pastures, and coastal sites.
Alaheʻe is a tree species native to the Hawaiian islands, excluding Niʻihau and Kahoʻolawe. Itsʻ hard wood was used for tools, while the leaves were used for dye. The flowers and fruit are used for making lei. Alaheʻe grows well in full sun or partial shade and requires minimal watering. It can be used as a single specimen or as a hedge.
ʻĀkia
(Wikstroemia uva-ursi)
ʻĀweoweo
(Chenopodium oahuense)
ʻĀwikiwiki
(Canavalia hawaiiensis)
ʻĀkia is a shrub that grows in Hawaiian forests. It has dark green to gray-green leaves, yellow flowers that turn into orange-red fruits. There are a dozen species of ʻĀkia that can thrive in various habitats. It can be used as a garden plant, ground cover, or hedge. They need minimal watering and can grow in different types of soil.
ʻĀweoweo thrives in soils that contain coralline and can be used for various purposes. When the plant matures, it develops woody stems and trunks which can be molded into topiary shapes. These plants can withstand full sun to partial shade, drought, wind, salt spray, and heat. Both native water and land birds utilize ‘āweoweo for food and nesting materials. In the past, ancient Hawaiians used the wood of ‘āweoweo to make shark hooks known as makau manō.
ʻĀwikiwiki is a hardy plant that thrives in direct sunlight and requires very little watering once it is established in the soil. Unlike invasive vines such as Maunaloa, which can be misleading, this plant does not overpower the host plant as it climbs. It is a great ground cover and is also capable of climbing trellises or other plants. The name comes from the word “wikiwiki,” meaning fast that refers to its rapid growth rate.
ʻIlima
(Sida fallax)
Kokiʻo
(Hibiscus kokio subsp. st.johnianus)
Maʻo
(Gossypium tomentosum)
Ilima is the official flower of the island of Oʻahu and can be spotted all across the dry and mesic forests of Hawaiʻi, from sea level to higher elevations. It is an ideal plant for landscaping as it needs minimal watering once it is established and can adapt to different soils and environmental conditions. ʻIlima can survive heat, drought, wind, and salt spray and can thrive in various types of soil, ranging from sandy to organic.
This Hawaiian hibiscus variety has thin-petaled red flowers that bloom continuously. In Ancient Hawaiʻi, its wood part was used to make high-quality charcoal, and flowers were used to make lei. As a medicine, kokiʻo was used for blood purification and as a laxative. This shrub/tree plant is a suitable hedge or screening plant in a Hawaiian landscape and is tolerant of drought.
Maʻo, also known as Hawaiian cotton, thrives in hot, dry, and windy areas near coastal and shore regions and can be used as low hedges and large ground covers. They require full sun and well-drained soils to grow properly. Maʻo is well-adapted to harsh environmental conditions such as wind, heat, drought, rocky terrain, soil salinity, and salt spray. When planting ma’o in clay soils, it is necessary to improve drainage as the plant cannot survive in extremely wet or flooded areas
Maʻo Hao Hele
(Hibiscus brackenridgei)
Nanea
(Vigna marina)
ʻOhai
(Sesbania tomentosa)
Maʻo hao hele is an endemic and endangered plant species that grows in dry to mesic forests of most Hawaiian islands except Niʻihau. It requires minimal watering and thrives best in full sun to partial shade. The plant produces two flowering periods yearly, each lasting up to two months. This plant is ideal for use in containers, as accents, or as specimen plants.
Nanea is a nitrogen fixer that has the ability to convert nitrogen into a form that other plants can use as a natural fertilizer. It thrives as a groundcover in open, sunny areas, especially near the beach. However, it is recommended to give nanea enough room to grow and expand.
ʻOhai prefers sunny, dry conditions and can tolerate wind. The prostrate forms make great groundcovers, while the shrub and tree forms can be used as screen covers or hedges. Overwatering and excessive fertilizer can hinder flower growth. The shrub and prostrate forms do well in well-drained, sunny pots. ʻOhai is also a nitrogen fixer and enriches the soil with it, which benefits other plants growing around it.
Pāʻū o Hiʻiaka
(Acquemontia sandwicensis)
Pōhinahina
(Vitex rotundifolia)
Pāʻū o Hiʻiaka is an excellent choice for use as a vining ground cover, especially in areas with sandy or salty soil or those prone to salt spray. This plant is named after Hiʻiaka, the younger sister of the volcano goddess Pele, and means “skirt of Hiʻiaka”.
Pōhinahina is a hardy coastal plant that is great for preventing erosion. It can withstand drought, wind, salt, and heat. The flowers have a pleasant aroma and are often used to make lei. Ancient Hawaiian’s ingested its leaves to help relieve various illnesses.