Hame (Antidesma pulvinatum) – Pests and the Environment.

    

    The most vexing section of these webpages to write is the section on Diseases & Pests. This is because my experiences often differ depending on where I ground a plant, as well as from the reports of other native Hawaiian plant enthusiasts. An example of this is hame. The first time I put a hame in the ground was at The Cultural Learning Center at Ka‘ala in Wai‘anae kai, O‘ahu, not far from its majestic mother trees growing in a beautiful and rare dry forest remnant. The young hame grew well but was mercilessly attacked by Chinese rose beetles (in contrast to the mother trees). Similarly, on a visit to the Maui Nui Botanical Garden in Kahului, I saw the same rose beetle damage to the young hame planted there. Most recently, I have been planting hame at Leeward Community College in Pearl City, O‘ahu. There, the plants often become heavily infested with scale insects, but, so far, none have been attacked by Chinese rose beetles. Nearby (also in Pearl City), my friend David Eickhoff has some beautiful young hame trees that are free of Chinese rose beetle damage.

    Even more surprising, I have discovered these differences in pests can manifest over very short distances. For example, again at Leeward Community College, there are kauila (Colubrina oppositifolia) on the lower campus that almost never show signs of black twigborer damage. Yet, just a few hundred yards away is a row of young kauila that are consistently attacked by the twigborer.

    So what insights can we discern from these observations? First, as more and more people incorporate native Hawaiian plants into their gardens, we should expect more and more reports of new disease and pest problems associated with each native species. And, second, we are likely to discover that relatively minor changes in where you plant your native Hawaiian plant within your garden — to a slightly wetter site, to a more windy site, to a site with less shade — may do more to combat a disease or pest than a host of chemicals.   

Habitat & Appearance: Wagner et al. (1990) describes Antidesma pulvinatum as a tree (2-)4-12 meters tall, endemic to dry and mesic forests on O‘ahu, Moloka‘i, Maui, and Hawai‘i, with irregularly corrugated bark. (It was also recently reported growing on Lāna‘i.) I have only seen this species on O‘ahu, in the dry forests of the Wai‘anae Mountains where they were all quite large trees a foot or more in diameter at their base. The ovate leaves are shiny on top, with new leaves often having a bronze or pinkish tinge. The undersurface of the leaves have tufts of hairs in the angles formed by the lateral veins and midrib, which distinguishes A. pulvinatum from the other endemic hame (A. platyphyllum) which does not have these tufts.

    Hame are dioecious (male or female flowers are on separate trees). The tiny male flowers are pictured in the header photograph above. Female flowers are also in panicles. When pollinated, these develop into a cluster of small fruits which turn soft and red to purple when ripe, with each fruit containing 1-2 flattened seeds. 

(Top to Bottom) Ripe fruits (photograph courtesy of Forest & Kim Starr ©). Seeds. Seedlings. Young tree at Maui Nui Botanical Garden with heavy Chinese rose beetle damage (photograph courtesy of Forest & Kim Starr ©). Young tree in Pearl City, O‘ahu, with no Chinese rose beetle damage (photograph courtesy of David Eickhoff ©). (Header photograph of male flowers courtesy of David Eickhoff ©.)

Hame in Hawaiian Culture: Hawaiians fashioned the very dense wood of hame, which sinks in water, into tools and weapons such as spears, digging sticks (ʻōʻō), and kapa anvils for beating olonā (Touchardia latifolia), as well as into beams for hale. Juice from the ripe fruits was mixed with kamani (Calophyllum inophyllum) oil to make a bright red dye for bathing malos. The leaves were eaten to stop vomiting, while the bark, mixed with other plants, was used as a wash for sores and ulcers.

Collecting Seeds: Please note that my observations are limited to wild and cultivated hame on O‘ahu; optimum collection periods may differ on other Islands. For wild hame, look for ripe fruits in the fall and winter. Cultivated hame often have a more prolonged and/or multiple fruiting season that can extend throughout most of the year.

    Collect hame fruits when they are soft and red to purple. Remove the fruits' skin and pulp by hand from the 1-2 seeds within and air dry. Seeds stored in a refrigerator remain viable for 5-plus years.    

Growing from Seed: After soaking your hame seeds overnight (2-3 days for refrigerator-stored seeds), sow them using Method One. They should begin sprouting in about a month. Transfer the seedlings to individual pots after they have 2-4 true leaves.

    Unfortunately, hame seedlings are a pest magnet. Scale insects have been my most common infestation, but broad mites, aphids, and mealybugs also attack the seedlings. Rather than treating the infestations after they occur, I use a regular schedule of alternately spraying my seedlings with horticultural oil or sulfur every month (i.e., first month oil, second month sulfur, third month oil, ...) to ward off these pests. While I have read that spraying plants with horticultural oil and sulfur can cause leaf burn or worse, I have not see this happen with my hame seedlings (unless the leaves were already heavily infested with a pest); it seems the one month timing is enough separation to prevent a negative interaction between these two pesticides.

    With pests under control, your hame seedlings should grow quickly and be 12-18 inches tall in about six months. You can then start scouting for a place to plant them in your garden.

Growing from Cuttings: I have never tried to grow hame from cuttings, and do not know of anyone who has tried. However, the tropical alien Bignay (Antidesma bunius) is regularly propagated using greenwood cuttings and air-layering, so I encourage someone to try rooting the cuttings of our native Antidesma. If successful, this would be particularly advantageous since hame is dioecious.

Growth in the Garden: I have always planted out my hame when they were 12-18 inches tall in a site with full sun or partial shade; they did fine under both light conditions. Unfortunately, while all the wild hame I have ever seen were in dry forest where drought is common, all my cultivated hame have been incapable of enduring any type of prolonged drought. Therefore, I have always committed myself to regular weekly or biweekly watering. Depending on the rainfall at your site, your watering schedule may differ. Fortunately, a hame lets you know if it needs water — its papery leaves will either wilt or fall off.

    Sap-sucking pest infestations are common and deadly for young hame, therefore, the best strategy is to get them growing quickly until they are larger (six-plus feet) and better able to endure these attacks. Do this with regular watering and light fertilization. Additionally, you may want to regularly (every 3-6 months) treat your young tree with a systemic pesticide, or regularly spray (every 2-4 weeks) it with horticultural oil or insecticidal soap. Under best conditions, your hame will be six or more feet tall in a couple of years, and you can then be less vigilant and caring.

    Many of my older hame have died tragically, several in a brushfire and a few from girdling by careless weed-trimmers. Therefore, I do not have any firsthand knowledge on how long it takes for hame to mature and start flowering and fruiting. My best estimate (based on conversations with others) is that you will be waiting 5-10 years for those first fruits. Also remember that hame are dioecious, so plant several in your garden if you want to better the odds of having at least one male and one female tree.  

Diseases & Pests: Please read my discussion of pest inconsistencies in the Introduction above. Seedlings, saplings, and mature trees are all prone to infestation by sap-sucking arthropods such as scale insects, aphids, thrips, and mites. However, these infestations are only life-threatening for young hame. For large saplings and mature plants, I normally let nature run its course, and wait for natural predators such as ladybird beetles to control these pests. For small plants, I usually intervene with repeated sprays of horticultural oil along with a systemic insecticide. Chinese rose beetles will eat the leaves of hame of any age. While these attacks leave a plant unsightly, they have never killed any of my hame. Refer to Enemies in the Garden for methods of combating Chinese rose beetles. 


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