Norfolk Island Pine (Araucaria)
Plant Health Problems
Diseases caused by Physiological/Environmental Factors:
Branch drop, physiological.
Entire branches yellow and drop. This frequently starts at the bottom of the
plant and progresses upward. This condition has been associated with low light
and overwatering.
Branch drop can be minimized by careful attention to light and watering
practices. It is best to allow the potting mix to dry between waterings.
Insect Problems:
Mealybugs, Pseudococcus aurilanatus, P. ryani and Planococcus
citri.
Pseudococcus aurilanatus, P. ryani, and citrus mealybug may attack this
plant. Among the compounds registered for control of this pest in Connecticut
are insecticidal soap, horticultural oil, malathion and imidacloprid. When
needed, spray with insecticidal soap or ultrafine horticultural oil being sure
to contact the insects with the spray. If the plant is outside for the summer,
malathion can be used. Imidacloprid, applied as a systemic to be taken up by
the roots, will provide long-term control. Consult the labels for dosage rates
and safety precautions.
Scales, Eriococcus araucariae, Chrysomphalus
rossi.
These and other scales are known to occur on this plant. Among the
compounds registered for control of this pest in Connecticut are insecticidal
soap or ultrafine horticultural oil applied as needed. Malathion can be used if
the plant is outside. Scales producing honeydew can be controlled with
imidacloprid. Consult the labels for dosage rates and safety precautions.
Twospotted spider mite, Tetranychus urticae.
This is the most serious pest of Norfolk Island pine. It infests the leaves,
which turn orange, giving the plant a generally unhealthy appearance. Sometimes
the mites form webs, which more or less enclose the foliage. Among the
compounds registered for control of this pest in Connecticut are insecticidal
soap and ultrafine horticultural oil. Spraying with either product will give
sufficient control if applied at least twice at 7-10 day intervals. Special
care should be taken with soap or oil to obtain thorough spray coverage,
because they only work on contact. Commercial growers can use hexythiazox or abamectin
in greenhouses. Consult the labels for dosage rates and safety precautions.