HAWAI'I GARDENS
Water, soap can fight garden pests
By Heidi Bornhorst
Q. I need your advice about my red and pink gingers. I've noticed that my once-beautiful garden of gingers is slowly withering before my eyes. The leaves have a thick layer of black soot-like substance and the flowers are speckled with a lime-green, seed-shaped substance. Also, when I trim the plants, lots of tiny white flying insects emerge from the leaves. Please help. I've been reluctant to use any type of chemical because I also have two small dogs who enjoy romping around in the yard.
A. This sounds like sooty mold from the feeding of aphids (the lime-green things) and white flies.ÊThere are simple ways to control these pests without harming your dogs.
First shoot the plants with a fairly strong stream of water, aiming for the undersides of the leaves where the insects like to hide. Water alone helps knock down insect pest levels. Then make a soapy water solution (one tablespoon liquid soap or peppermint soap to one gallon of water) and spray this on the aphids and whitefly eggs. Wait a day or so and with a soft rag, and wipe the leaves to remove the sooty mold and dead aphids.
Some people use Simple Green at the same rate, or even a little stronger, with good effects.
Q. My girlfriend has a gourd tree, The gourds that are used to make the uli-uli hula implements. Everyone I've asked says that it's called the uli-uli tree or the uli-uli fruit; I know that it has another name (besides its Latin name); do you know it?
A. This great tropical American tree has many names. The Latin, for all you budding scientists, is Crescentia cujete. It also is called la'a mia and calabash tree. It is related to the sausage tree, African tulip, gold trees, pink and purple tecoma trees, and jacarandas, among many other, trumpet-flowered relatives. Look for the green, trumpet-shaped flowers, close to the trunk, which will in time, if pollinated, produce the mini tree gourds.
In bloom
I am starting to see gorgeous red tree-type poinsettias in bloom in some of our older neighborhoods. Amazingly, plumeria trees are still in flower here and there, on some branches on some trees. Aloe is starting to bloom with nice orange colors. Christmas cactuses are in bud if they've been watered and nurtured carefully through the year.
Thai hybrid crown of thorns are looking very lush and colorful at some of our drier botanical gardens. Hong Kong orchid trees are blooming well on the leeward side, but look a little battered in windward areas.
Bougainvillea, in so many colors (thanks largely to the late great plantsman Donald Angus), are looking fabulous all over the Islands. The bits of rain seem to have done them well, as they are looking lush and floriferous.
Holiday decor
I like simple holiday decor — stuff that you find in nature, transformed into art — and I saw a simple festive idea along my daily commute that I wanted to share:ÊA home along a busy street has a high (and ugly) hollow tile retaining wall, but its wall is cloaked in creeping fig or Ficus retusa. At this time of year, there are large red bows stuck amidst the creeping vines. The colors are very bright and cheerful together.
Any of you observant, artistic readers seen any decor that you think is naturally artistic?ÊPlease let me and your fellow readers know about it.
Heidi Bornhorst is director of Honolulu's botanical gardens.
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