The flowers of lehua ʻāhihi differ from those of other  ʻōhiʻa, being less like a pompom and more like thinly bristled paint brushes (photograph courtesy of Gerry Carr CC BY-NC 4.0). These nearly ripe fruit capsules will soon turn black and woody, split open (cross-like), and release their numerous tiny seeds to the wind (photograph courtesy of Neal Kelso CC BY 4.0). Lehua ʻāhihi has shiny hairless leaves with red petioles and stems (photograph courtesy of J.B. Friday ©). Header photograph courtesy of Daniel Ward CC BY-NC 4.0).

Wild lehua ʻāhihi are often scraggly small trees growing on windswept ridges; note other Metrosideros species growing nearby to the left and below (photograph courtesy of Neal Kelso CC BY 4.0). However, in more sheltered locations, lehua ʻāhihi can become quite large; note the odd aerial roots (photograph courtesy of J.B. Friday ©). Two cultivated lehua ʻāhihi: one doing exceptionally well and another not so much (struggling plant photograph courtesy of Daderot Public domain).

Growth Requirements

General

Accent

Hedges

Specimen Plant

Lehua ʻāhihi is a good tree for moist areas. A rich, well drained soil produces the best results. [2] It does not appear to any more difficult to grow than ʻōhiʻa (M. polymorpha, M. macropus) and can grow at near sea level locations. Provide full and perhaps a little more watering than some other Metrosideros spp. in cultivation and you will be rewarded with a very floriferous, which means it flowers a lot, shrub or tree. [David Eickhoff, Native Plants Hawaiʻi]

Lehua ʻāhihi are sensitive to root disturbance. A few planting guidelines can help: Dig a larger planting hole than the root ball, perhaps as much as twice as large. Put good drainage material such as black or red cinder in the bottom. When planting lehua ʻāhihi never splay out the root ball but gently place in hole as is. Nor should lehua ʻāhihi be planted too deep. Soil should never cover the surface area around trunk base. Better to err on the side of planting too high than too low. Water soil thoroughly. A final watering of B-vitamin solution will help to alleviate stress and encourage new root growth. For small plants water everyday until established; larger plants every two or three days should suffice. New signs of liko, new growth, is a key to a successful planting. [David Eickhoff, Native Plants Hawaiʻi]

Apply 13-13-13 slow release fertilize every six months. Foliar feeding in early morning with a water-soluble or an organic fertilizer (e.g. kelp or fish emulsion) at one-third to one-fourth the recommended strength every other month has proved beneficial.

Moist

Lehua ʻāhihi does well with moderate amounts of water. Mulching helps to retain moisture in hot open areas.

Soil must be well drained

Full sun

Partial sun

Tolerances

Wind

Soils

Cinder

Organic

Pests and Diseases

Caterpillars can be detructive to new growth (liko). Black twig borer can be a serious problem. Cut off infected material well below the dead area, wrap securely in a plastic bag and dispose of or completely destroy right away. Whiteflies can infest ʻōhiʻa as well.

ʻŌhiʻa is susceptible to attacks by the bright yellow ʻōhiʻa, or guava, rust (Puccinia psidii) especially in wet environments or during the rainy season. This aggressive rust can be a serious problem if not taken care of in a timely manner. At the first sign of ʻōhiʻa rust, infected material can be carefully trimmed off, bagged securely, and disposed of. One untested suggestion is to put cut pieces in a bottle with a small amount of alcohol before disposing. Then, the plant and any others, including relatives (Eugenia spp., Syzygium spp.), in the area should be treated with a fungicide immediately. [6]

Never add trimmings damaged by ʻōhiʻa rust or black twig borer to a compost pile. [David Eickhoff, Native Plants Hawaiʻi]. 

Refer to the Pests & Diseases page for ways to deter these attacks.  

Galls left by insects occasionally disfigure its leaves. Adult female psyllids (jumping plant lice) lay eggs inside the leaves. When the nymphs hatch, they feed on the leaf from the inside, secreting substances that stimulate abnormal plant growth and form galls. read Google AI on "psyllid galls on metrosideros tremuloides"

Special Features and Information

General

ʻŌhiʻa (Metrosideros spp.) belong to the Myrtle family or Myrtaceae with a current figure at over 5,650 species. [5]

Other non-native relatives, many naturalized in Hawaii, are numerous and include myrtle, tea tree, strawberry guava or waiawī ʻulaʻula, pineapple guava or kuawa, allspice, eucalyptus, melaleuca or paper bark, bottlebrush (Callistemon), and Surinam cherry (Eugenia uniflora)--to name a few. Some of these have become seriously invasives displacing large tracts of native forests with a monoscape of a single species. An extreme example of this is the highly invasive strawberry guava (Psidium cattleianum) where little vegetation can grow beneath its dense canopy.

Native Metrosideros include five endemic species: Lehua ʻāhihi or ʻāhihi (M. tremuloides), lehua papa (M. rugosa), and three known by the name ʻōhiʻa (M. polymorpha, M. macropus and M. waialealae). But it is the species polymorpha that is by far the most common and widest ranging ʻōhiʻa in the islands.

Other native Myrtaceae members include the indigenous Beach cherry or nīoi (Eugenia reinwardtiana), and two endemics: the endangered Koʻolau eugenia or nīoi (Eugenia koolauensis), and the fairly common ʻŌhiʻa hā (Syzygium sandwicensis).

This species is unique among Metrosideros spp. by its characteristically small leaves with bright red petioles (portion from stem to leaf) and overall weeping habit.

Hawaiian Name

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Etymology

The generic name Metrosideros is derived from the Greek metra, heartwood, and sideron, iron, referring to the very hard wood of these plants [Gledhill 2008].

The specific epithet tremuloides means to tremble or to quake in reference to the leaves trembling in the wind.