Conditions must be right for anthuriums to thrive

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Hi Nick. I read your column and find it very informative. I hope you can solve my problem. I live in the lower Piihonua area and have planted hapu for shade and planted anthuriums with advice from many people, but I still have the same problem of the anthuriums doing well for a while then gradually dying.

Hi Nick. I read your column and find it very informative. I hope you can solve my problem. I live in the lower Piihonua area and have planted hapu for shade and planted anthuriums with advice from many people, but I still have the same problem of the anthuriums doing well for a while then gradually dying.

It ends up with just a brown stump where it was once thriving. I am planting in gravel with hapu chips with logs to form planting areas. Can you tell me what could be the problem and how to solve it so that I don’t keep losing my plants and flowers? I would appreciate any advice to keep my plants thriving. — E.M.

First, obtain and read the University of Hawaii College of Tropical Agriculture and Human Resources publication, “Anthurium Culture in Hawaii.” Anthuruim plants have specific environmental requirements for their development. These are spelled out in the publication. Oftentimes, anthuriums decline and even die, not because of insects or diseases, but rather because their growing conditions are not met. Here is a summary of their needs.

Night temperatures should never be lower than 65 degrees, with the day temperatures hovering around 80 degrees. The shade requirement is important and will vary with the cultivar and age of the plant, but normally ranges from 50 to 90 percent shade. The plants grow best in a well-aerated medium; wood chips, tree fern chips, macadamia nut shells, volcanic cinder and some artificial media have all worked well.

Good drainage and aeration are essential.

There are several insect pests and diseases that will cause either a slow decline or cosmetic injury. The gradual death of a plant may be caused by one of several fungal root rotting organisms in conjunction with the burrowing nematode. The publication mentioned above will give you a full description of symptoms of the disease, including pictures and various control measures.

Although it is possible that you have the nematode or the fungus, my inclination is that it is an environmental problem, especially having had hot, dry days during this past summer.

Dear Garden Guy, I have many coconut palms on my property in Hawaiian Paradise Park that appear mature enough to be producing nuts but do not.

One of them produces long and skinny nuts with almost nothing in the nut. The others seem to put out flower stalks but never set fruit. I am interested in better coconut production. Do you have any suggestions for what to do with coco palms that either produce poor nuts or none at all? I have heard of using rock salt (to more closely mimic coastal soil salinity), epsom salt (for Mg), and just organic fertilizer in general. Any particular suggestions? As always, thank you for your column, advice, and insights! Aloha, Mary

Palm trees appearing to be mature and actually being mature may be two different things. In general, coconut palms will flower in four to six years. They may not actually produce fruit, however, until they are 6 to 10 years old. And if growing conditions are unfavorable, they may not produce until they reach 15-20 years of age. Full production is at 15-20, they can potentially produce until they are about 80 years old.

Although coconut palms are tolerant of dry soil conditions, for optimum fruit production regular irrigation is recommended, especially during drought conditions. Palms can also endure temporary waterlogged soil conditions but will decline and even die when exposed to prolonged periods of wet, poorly drained soils. I would not recommend applying salt to the ground. Coconut palms will tolerate saline water and soils, as well as salt spray, but this does not mean that they prefer it.

Coconut palms will respond to applications of a balanced fertilizer, such as 10-10-30. Epsom salt is magnesium sulfate. I would not apply it unless a soil analysis indicated the need. Organic mulch and fertilizers are good and highly recommended.

Hilo resident Nick Sakovich is a professor emeritus of the University of California. He has worked in the field of agriculture for 30 years. Email your questions to Sakovich at askthegardenguy@earthlink.net.