Pahole Rare Plant Facility – FY 2006 Report


The objectives of the Outplanting and Monitoring project at the Pahole Rare Plant Facility (PRPF) are listed below. Priorities will shift as propagation material is available and as plants are reintroduced, but should follow the order given here.

  1. Provide facilities for the ex situ cultivation & storage of mid-elevation species (priority to species with less than 50 individuals in the wild) that cannot be stored as seed or in tissue culture.
  2. Propagation of rare plants for reintroduction from Oahu as needed for land managers with protected habitats.
  3. Production of more common native species for restoration efforts, provided time and resources are available and the operation is self-supporting.


Provide facilities for the ex situ cultivation of Plant Extinction Prevention Program mid-elevation species (less than 50 individuals in the wild) that cannot be stored as seed or in tissue culture, with priority to Oahu species.

The Pahole Rare Plant Facility currently contains 14 PEP species in its collection. PRPF is currently working on a Master Plan for the facility that will provide increased area for propagation of rare species. The master plan will address propagation space as well as infrastructure to support propagation such as water collection, water storage, irrigation systems, working space, pesticide storage, seed storage, storage of materials for landscape scale fencing projects, helipad space, fire protection infrastructure, and office space. PRPF staff has met with major partners at Pahole, including the Army Environmental Program, The Nature Conservancy, and the University of Hawaii-Manoa Botany Department to seek their input in the Master Plan.

This year PRPF began work on an additional 2500 square feet of nursery space to be located on the northwest side of the lower building at Pahole. The staff attempted to seek bids for construction of the nursery in the spring of 2006 through the Pacific Cooperative Studies Unit (PCSU) at the Research Corporation at the University of Hawaii (RCUH). PRPF did not receive any bids for this project due to the surplus of work available in the construction industry. The staff looked at other strategies to complete the nursery construction during FY 2006.

PRPF split the tasks between DOFAW and the Army Environmental Program. The groundwork completed was a new access road to the nursery and grading of the site of the new nursery. The DOFAW equipment operator and the NARS Field Project Specialist did this grading. In August and September of 2006, the staff began construction of retaining walls along this access road and along the lower boundary of the nursery site. The US Army Environmental Program supplied the keystone blocks and the labor to construct these retaining walls. The US Army Environmental Program will be purchasing an engineered greenhouse kit on the site once the groundwork is completed. PRPF expects this nursery space to be completed by the middle of fiscal year 2007.

During FY 2006, PRPF completed the installation of the new fiberglass gutter system on the two large buildings at the Pahole Nursery. This will greatly increase the efficiency in collecting rainwater for the year round irrigation needs at the Pahole nursery. PRPF was previously only harvesting water from the long part of the lower building. PRPF added fiberglass gutter to the upper building and the other smaller side of the lower building, in addition to replacing the gutter on the long portion of the lower building. This doubles the water collection capabilities at Pahole. The Pahole Rare Plant Horticulturist, the NARS Field Project Specialist, and a summer intern did the labor for this gutter installation. PRPF purchased a third 20,000-gallon water storage tank for the nursery that will bring the total storage capacity to more than 60,000 gallons. In addition, PRPF purchased a storage/transfer tank with a float system and pump system to attach the upper building to the above mentioned storage tanks. The tanks and pumping system has been ordered and the staff hopes to have it installed by November 2006. PRPF hopes this upgrade of the water system will allow PRPF to collect enough water during the rainy season to supply the water needs for the Pahole Nursery throughout the entire year.

Another construction project that was completed this year at the Pahole Nursery is work to bring the site in compliance with the Americans with Disabilities Act (ADA). The DLNR Engineering Division managed this project with help from the Natural Area Field Project Specialist. A concrete handicap parking stall was constructed on the west end of the lower building, the sidewalk along the lower building was modified, a concrete ramp into the lower building was built, a second handicap parking stall concrete pad was made in front of the upper building, and a concrete handicap access ramp was built to the composting toilet. An outside construction contractor completed the project. A total of nearly $100,000 was spent on these improvements.

Propagation of rare plants for reintroduction from Oahu as needed for land managers with protected habitats.

This has been another year of change for the staff at the Pahole Rare Plant Facility. PRPF was finally able to hire a full time Horticulturist to manage the facility in November 21, 2005. This replaces a horticulturist that filled the position from November 2004 to February 2005. Therefore, the Pahole Rare Plant Horticulturist position was vacant for 5 months of FY 2006. The staff assisted the Army Environmental Program with maintenance and propagation of species associated with the Makua Implementation Plan. Most of PRPF Horticulturist time was spent maintaining these plants. The staff also assisted in propagation of plants for the PEP program, The Nature Conservancy, and the University of Hawaii.

A total of 2,486 plants were produced at the Pahole Rare Plant Nursery during FY 2006: Bobea sandwichensis 16, Bonamia menziesii 6, Colubrina oppositifolia 1, Flueggea neowawraea 67, Schiedea obovata 322, Silene perlmanii 1, Urera kaalae 8, Chamaesyce herbstii 23, Cyanea crispa 6, Cyanea grimesiana subsp. obatae 116, Cyanea longiflora 18, Cyanea superba subsp. superba 1, Delissea subcordata 299, Dubautia herbstobatae 47, Eurya sanwicensis 1, Hedyotis degemero var. degemeri 1, Hedyotis parvula 2, Hespermannia arbuscula 19, Hibiscus brakenridgei subsp. mokuleianus 1, Labordia cyrtandrae 9, Melanthera tenuifolia 83, Melicope lydgatei 2, Neraudia angulata 107, Nototrichium humile 225, Phyllostegia kaalaensis 349, Phyllostegia mollis 4, Plantago princeps var. princeps 94, Prichardia kaalae 186, Schiedea kaalae 208, Schiedea nuttallii 93, Stenogyne kaalae subsp. sherffii 65, Tetramolopium filliforme 35, and Viola chamissoniana subsp. chamissoniana 71. (Total 2,486 plants)

Production of more common native species for restoration efforts, provided time and resources are available and the operation is self-supporting.

PRPF has grown plants from 26 species of common natives to replace weeds and create native canopy in all planting sites. The staff will continue to grow these species as outplanting projects dictate and space in the facility permits.