How gardens help the Bay
Plants vs. Runoff
Plants are effective in removing pollutants from storm water through a process called bio‐filtration. In this process, the soil traps and plant roots breakdown pollutants into food or fertilizer. Some of the pollutants that can be trapped or removed by the soil and plants include: suspended solids (dirt), nutrients (nitrogen and phosphorous), heavy metals (lead, copper, and zinc), micro‐organisms (bacteria), and surfactants (detergents, oils, and grease)
In contrast, stormwater runoff occurs when impervious surfaces (like rooftops and paving) prevent rainwater from soaking into the ground at or near where it falls. Instead, rain falls on the roof, spills into the gutter, down the downspout, across the impermeable driveway and sidewalk into the street, then the stormdrains, and ultimately into creeks, rivers and the ocean, all the while unavailable for local irrigation, and without ever nurturing the land.
In Hawaii, increasing urbanization leads to more and more impervious surfaces and higher concentrations of pollutants making their way into our ocean ecosystems. In the Maunalua Bay region, there are over 5,000 storm drains and 5 shopping centers that all feed into Maunalua Bay.
By doing your part to plant gardens on your property, you help mitigate the impacts of so much impervious ground cover in the Maunalua Bay region. Here are some quick gardening tips:
Look for a sunny spot on your property that might be bare ground or filled with invasive plants
Planting in a low spot or depression in your yard where water collects can be a good start towards creating a rain garden
Plant native species
Rain gardens are particularly good at
biofiltration but all plants can help
reduce pollutants in stormwater
Don't Forget About Pollinators!
Pollinators help plants that bring us food and other resources. By carrying pollen from one plant to another, pollinators fertilize plants and allow them to make fruit or seeds. Pollinator health is critical to our food system and the diversity of life across the world.
Bees are one of the most well-known pollinators, but there are a variety of other pollinators including ants, flies, beetles, birds and more!
Bees here in Hawaii are facing threats from introduced species like the varroa mite and the small hive beetle which spread disease and infest local hives. Planting a variety of ornamental flowering plants in open spaces around the perimeter or within the boundaries of a vegetable garden will help our bees find food more easily and avoid stress from low resources.
Some tips for a pollinator friendly garden include:
1) Limiting or completely forgoing pesticide use
2) Plant flowers with pollen and nectar
3) Plant in drifts (i.e. plant multiples of a plant together so pollinators can more easily find large patches of colorful blooms)
‘öhi‘a is a very attractive tree that has been used in the landscape industry for many years. It grows at all elevations, prefers
a lot of sun, and needs to be watered every 2-3 days.
ʻAʻaliʻi is a dense shrub/small tree that also grows well where most plants do not, preferring little water and dry soil. It’s known for its resiliency, as quoted in an ancient warrior boast: “He ʻaʻaliʻi au; ʻaʻohe makani e hina ai” meaning “I am an ʻaʻaliʻi shrub; no wind can push me over.”
ʻIlima papa, more properly called ʻilima kū kahakai makes excellent groundcover for open, sunny and/or windy coastal areas. Just be careful not to over water!
