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QUESTION: What causes the holes in my rose leaves?
ANSWER: Every rosarian living in Hawaii recognizes the telltale signs after Chinese rose beetles have made a feast out of the foliage on their rose bushes. Left uncontrolled, these beetles may make a buffet out of every leaf on every bush growing in your rose garden.
A close relative of the Japanese rose beetle found on the mainland, the Chinese rose beetle is probably the most common rose pest to be recognized locally. If you have never strolled in your rose garden after sundown, you probably have not seen them, as they are nocturnal by nature.
Unfortunately, in the morning you find the damage they have left behind: leaves with so many holes in them that they often resemble lace and, in some cases, damage to rosebuds as well.
To control the beetles, plant roses close to a light source, whether a street light or an outdoor house light. Also, local gardeners are known to visit their roses at dusk with chopsticks in hand to pick adult beetles off leaves. Destroying the adult population will break the life cycle of this insect and allow your roses to recover. Spraying or treating the plant for these insects is not effective.
Learn more and take the mystery out of growing beautiful roses from rosarians of the Honolulu Rose Society by attending the Rose School. Visit www.honolulurosesociety.org.
Marsha Yokomichi is a Honolulu Rose Society rosarian. Jayme Grzebik is the urban horticulturist with UH CTAHR Cooperative Extension Service; she can be contacted at grzebik@hawaii.edu.
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