Cordia subcordata

photo credit: Forest and Kim Starr

Best practices for survivability and field observations

Respondents noted that it is an overall hardy plant known from specific coastal areas on Oahu (Pia Valley, Pearl Harbor, Keawa’ula, various beach parks, public lands) and shorelines specifically. Several said it is a fast grower. Another noted that the species will get low and bushy in higher wind environments. It does really well as an ornamental landscape tree in the urban environment. Another noted that mo‘olelo (stories) tell of the ‘Ewa moku on O‘ahu covered with kou. In modern, urban landscapes some may find that the plentiful large, hard, round fruit are a hazard in walkways needing frequent maintenance. The seed is used in cultural practices of lei making, wood, and kapa cloth dyes.

Stressors and pests

One respondent noted that larger trees (probably 20-25 gallon pots) became really well established in their particular outplanting site. A couple of respondents said that water is required in the beginning for the tree to become adequately established, one saying especially during the first 3 years. Young trees may become partially defoliated and weak, and older trees die from Kou Leafworm Caterpillar (Ethmia nigroapicella) in some areas (for example, Kahului, Wailuku). Noted pests include rose beetles, black twig borer, caterpillar damage, and predation of seeds by rats. One said that roots can rot in wetter areas.

Availability and propagation

Mixed reviews on its availability (DLNR-DOFAW is noted as wanting to plant it). Many note that it is easy to propagate from abundant seeds. One recommends collecting when the fruit is still white (not brown) and planting immediately for good germination. The same respondent notes that “brown fruits have seeds that have entered dormancy and can germinate sporadically for years and years.” A couple of respondents note that some varieties grow easily from cuttings, like the low growing “naio papa type” (from Hawai‘i Island) which is said to be hardier.

Survey Results

For information about the survey, refer to our article: on Coastal Plants for Creating Green Breaks