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Ficus Scale
Large brown
bumps indicate a Scale
infestation
on Weeping Figs
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By: Sandy Feather ©2009
Penn State Cooperative Extension |
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Q.
We have a five-year-old Ficus plant that has sentimental value
to my wife since it belonged to her mother. This past summer we noticed what we
think are scale insects
forming on the branches of this weeping fig. We removed the
brown bumps
as soon as we found them, and the Ficus seemed to be doing well. But
now the plant has started dying off. It’s down to one healthy branch
with some faint signs of new growth. No sign of the scale, but I
don't know what the early signs of scale are. I just know the large
brown bumps.
What do I need to do
to get this plant back to good
health? Right now I am watching for more scale to appear, and watering it
several times a week with a Miracle-Grow mix. Will the scale come
back, and if so what can I do to get rid of it once and for all?
A. There are
several species of scale insects that infest weeping figs (Ficus
benjamina). If you are not seeing the brown bumps, you have them
under control for the moment. Continue monitoring the plant for
them, and physically remove any that you find. Immature scale
insects are known as crawlers, because it is the only time in their
life cycle that they are mobile. They range in color from yellow to
orange-yellow, but they are very small and can be difficult to see.
Once they settle into place on a stem or leaf, they insert their
piercing-sucking mouthparts and begin to feed. Then they secrete a
waxy coating over themselves that protects them from predators and
makes them almost impervious to insecticide applications. Physical
removal works over time, and is much safer than using an insecticide
indoors.
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Weeping Fig (Ficus
benjamina) is popular for Bonsai |
I am concerned that you are overwatering this plant. Now that it is
down to “one healthy branch,” it does not use as much water as it
did when it was full. By watering several times a week, you may be
keeping the soil too wet, which will eventually lead to root rot.
Allow the top couple of inches of soil to dry thoroughly between
waterings. Stick a finger into the potting mix and feel, rather then
guessing.
Consider repotting your ficus, especially if it has been growing in
the same container for a while. You will be better able to judge the
health of the roots once you remove it from the pot and get a look
at the root system. It the roots are white and firm, they are still
healthy and you can replant the tree in fresh soil in the original
pot. If the roots are brown and mushy, that is a sign of root rot.
Trim the ailing roots back to healthy ones as much as possible and
repot the tree in a smaller pot. This reduces the soil volume and
allows it to dry faster between waterings.
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Although your impulse to fertilize this plant to help it recover may
seem intuitive, it may cause more harm than good. Fertilizers are
basically salts, and salts can build up in the soil over time. If
you have ever noticed a white, crystalline substance on the soil
surface or the sides of a clay pot, you have seen soluble salts.
They can build up on the roots, too, and burn any tender new roots
that the plant produces. Also, if this plant is suffering from root
rot, you do not want to push new top growth that the reduced root
system cannot support. Hold off on fertilizing your ficus any more
until the root system recovers. You will know because the plant will
begin to sprout more healthy new growth. You can also pop it out of
the container from time to time to examine the roots. Firm, white
roots are also evidence of recovery.
We typically do not recommend fertilizing houseplants in the winter,
from October through late March or early April. Our houseplants are
not actively growing during the gray days of a typical western
Pennsylvania winter. Resume fertilizing in spring, when houseplants
respond to increased light levels outdoors by putting on new growth.
Always read and follow label directions as to how frequently to use
a fertilizer and how to mix it – more is never better when it come
to fertilizer.
Excessive nitrogen fertilizer can make plants MORE susceptible to
damage from insects such as scale, that feed with piercing-sucking
mouthparts, because nitrogen is a critical nutrient for them. By
fertilizing too frequently, you may actually be creating a situation
that favors the scale.
How valuable are
your trees?
Tree roots in
sewers
Trimming a Weeping
Cherry
Sandy's
Tree Tips
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