Seeds to Soil: Native Pollinator’s Field Pilot
Summary:
To support the Hawaiian ecosystem via local pollinators with special focus on native (especially endemic) species, Seeds to Soil is embarking on an initiative to determine if it is possible to create a pocket of pollinator-friendly habitat at Enchanted Gardens.
As per requests from both the NYC pollinator field team and the Enchanted Gardens team, we will focus on host and food plants that support native butterflies and bees.
Constraints:
The Enchanted Gardens site has a rapidly evolving program and field conditions. To accommodate potential changes to use of cleared areas, we are required to develop our plans in an impermanent manner. Additionally, if the habitat needs to be moved, there is only 1 site supervisor who would need to move anything we install by himself, so the entire mobile habitat must be mobile and straightforward to relocate by a single person.
It’s well established that the EG site has copious amounts of direct sun and wind paired with little rainfall. This means that moisture is not only limited, but quickly evaporates.
Implementation:
We are piloting a modular, movable pollinator’s field with the Tiny Plots milk crate planters utilized in our NYC-based urban pollinator’s field initiative. We will also be testing Kirinsou Grow Bags generously donated by program partner, GROW Externships.
For more information on the Tiny Plots system, please visit the Seeds to Soil website.
For more information on the Kirinso Grow Bags contributed by GROW Externships, please see this spec sheet.
As much as possible, soil will be sourced from the site to test viability for the selected species to be directly planted in the future. As this is an exploration of feasibility, we left the plants to see if there is enough rainfall to sustain any of them. Since we know already that water is going to be a key challenge, for this first pilot we’re experimenting with some passive water retention: half of the planting be mixed with absorbent scrap textile and mulch alongside soil from the site. The other half is soil from the site mixed with potting soil from the nursery.
We are selecting for native (especially) endemic Oahu plant species that are representative of the microclimate that can serve as pollinator food sources. Our final plant choices were made based off of our own research (sources below) as well as after consultation with the team at Hui Ku Maoli Ola, based on their visits to the EG site and what was available at their nursery. All plant species are drought resistant, tolerant of direct sunlight, and provide forage for native Hawaiian pollinators.
(Above: A’ali’i is planted in a Kirinsou bag filled with the red clay soil from EG to test its viability in the low rainfall area)
Helpful Resources:
2014 Hawaii Department of Transportation Ecological Zones and Native Planting List - Mesic Ecozone, Moderately Dry Ecozone, and Full Hawaii DOT Guidelines.
College of Tropical Agriculture and Human Resources (CTAHR) - Native Hawaiian Plants for Honeybees (Oahu)
Pollinator Partnership’s Selecting Plants for Pollinators (Hawai’i)
Xerces Society Habitat Planting for Pollinators: Pacific Islands Area
CTAHR Master Gardener Program: “Hawaii's Native Bees - Nalo Meli Maoli”
Meet the native pollinator-friendly plants
Mamaki: (Pipturus albidus) Host plant! Small shrub/tree. Ancient medicinal plant revered for healing properties.
A’ali’i: (Dodonaea viscosa) Host Plant! Low lying shrub/small tree. Abundant in the dry forests of Hawai'i, commonly occurs as a pioneer species.
Kulu'i: (Nototrichium sandwicense) Can reach a height of 4-7 feet, very dense foliage. Found in dry forests on the main islands.
'Ōhi'a-Lehua: (Mestrosideros polymorpha) Perennial evergreen evergreen tree/shrub. Most abundant tree on the main Hawaiian Islands.
Polinalina: (Vitex rotundifolia) shrub, can be found on the sandy coasts of all the main islands. Needs very little water, thrives in full sun.
'Ilima haupu: (Sida fallax) common shrub or ground cover on the coast and up to the dry and mesic forest. Known as the island flower of Oahu.
Meet the endemic pollinators
Kamehameha Butterfly
Koa Butterfly
Gallery
Pilot Updates
July 29, 2020
All the plants are green and happy. 5 of the 6 species have been deployed in brand new Kirinsou bags: polinalina, kulu’i, ʻōhiʻa lehua, a’ali’i, and ‘ilima haupe. They are watered in. The first 3 weeks there is so little rain that our Field Supervisor “cheats” and waters them twice.
August 31, 2020
The plants are looking pretty sad. Generally, the plants with passive water retention fared a little bit better, but not by much. The exception to this rule being the a’ali’i, which seemed to be doing better without the mulch and fabric scraps.
September 22, 2020
Pretty conclusive pilot: even these drought and wind resistant plants won’t survive at EG without a little more help. The a’ali’i and ʻōhiʻa lehua performed the best. Additionally, it’s unclear if the Kirinsou bags are best suited for this application.
Next Pilot: Mamaki in Tinyplots Planters
Mamaki is the centerpiece of our imagined native Hawaiian pollinator’s habitat because it is a host plant for BOTH the Kamehameha and Koa butterflies. We know that mamaki requires even more moisture than the other plants chosen in order to survive, so we are going to be experimenting with ways to maximize water retention at Enchanted Gardens so that we can attempt to create a small mamaki grove. Stay tuned for updates!