COMMON PESTS AND DISEASES
in the PNW
You can avoid most
pests and diseases by following some simple procedures:
Plant in
clean containers with soil that drains well. Repot when soil gets packed hard.
Clean up dead
leaves and other debris. Pests and fungus hide there.
Ventilate the
plants well.
Water, misted
or sprayed, will remove many pests. Water in the morning.
However, there are times
when keeping up is difficult and problems occur.
Outdoors, fuchsias are not
bothered by many pests or diseases. Rain and ventilation help keep them happy.
Rust can appear in spring or mostly in fall when it is unusually wet.
Indoors in greenhouses,
particularly in spring, aphids may line up on stems for the new, tender growth.
White flies can show up any time.
Over summer, root weevils can get into
containers, eat the roots and kill the plant, indoors or out.
Besides the many commercial
products available in gardening centers, there are some homemade recipes that
NWFS members have found to be less expensive, easily kept on hand, and they work
well when things get out of hand:
For aphids, white flies, spider mites, and thrips-
ISOPROPHYL ALCOHOL- 70 % 1
part alcohol- 3 or 4 parts water.
Add a ‘spreader sticker’/wetting
agent.* Spray it on the fuchsia, particularly under the leaves and on the stems.
(* Spreader
stickers increase the effectiveness of contact sprays. Examples:
A
couple drops of Ivory Liquid (soap, not detergent) in your sprayer bottle.
A
couple drops of vegetable oil like Canola, the lightest and least expensive.
Ivory bath soap can be grated & kept in a jar. 1 T per quart.
)
Sticky leaves? Cause: aphids and/or white flies. Both insects
secret a fluid that is sticky, "honey dew". Look under the
leaves for aphids, and if you disturb the leaves, and you see
some tiny white things fluttering about, then you have white
flies.
You
can treat both problems with an insecticide or you can mix a solution
of 1 cup of rubbing/isoprophyl alcohol and a cup of Simple Green
in a quart of water and spray directly on the insects. Plus
the Simple Green will wash the sticky substance off of the
leaves. After a few minutes you can spray the plant with clear
water to wash all of the solution off. Two or three treatments
3 days apart should take care of your situation.
For fungus problems like rust, botrytis, gray
mold-
HYDROGEN PEROXIDE,
3 %, use full strength.
(NOTE: A higher concentration than 3% may harm
the plant.)
Keep it in its brown bottle and add
the sprayer to it.
Spray it on leaves and stems.
Make sure the plants are
well-ventilated around the leaves and in the soil.
For slugs-
Remove them.
Look for babies as well
Get rid of them in whatever manner you prefer.
There are some good 'slug riddance' products on the market.
Put
whatever you choose near moist, shady areas like where slugs can get
under wood, leaves...
For yellow leaves-
1 T. Epson salts. Dissolve in a
glass of hot water.
Add it to your gallon watering can and water
the soil.
For cleaning pots, greenhouses, eliminating mold
and algae-
Bleach/Clorox- 7 % ¼ c per gal. Spray
or dip.
For root weevil
(aka black vine weevil, rhododendron root weevil,
strawberry root weevil)-
Several products have been tried- coco fiber,
fine mulch, coffee grounds…sticky goo, but the most effective controls, unfortunately NOT
homemade, are…
BENEFICIAL NEMATODES
Use as directed.
A watering can with a nozzle with small holes
works as well as spraying.
Apply again in August
Available in gardening centers,
locally and by mail order.
For removing water/mineral marks on
containers:
Soap and water.
Vinegar if plant cannot be removed from
container.
For disinfecting tools and containers:
Chlorine bleach is corrosive and
can cause pilling and discoloration on metal. Instead, try alcohol,
Listerine, Lysol, or Pine Sol. Then rinse.
RECOGNIZING PESTS AND DISEASES:
P or D- Symptoms/ Cause
Aphids-
Curled leaves or sticky leaves- you can easily see them on stems with their
long 'beak'/ Not well-ventilated.
Botrytis- Damping off. Young stems
collapse./ Not well-ventilated.
Gray Mold- Fluffy gray mold on plants. /
Not well-ventilated.
Spider mites- Leaves get webbed, dappled and stripled with red or bronze areas, and drop. Tiny mites
can be seen under the leaves. / Too dry.
Root weevil - Plants collapse. Small white
grubs are found feeding on roots. Nearby rhodies show notched leaf margins- a warning.
Rust- Orangish, rusty areas
appear, usually under the leaves. /Not well-ventilated;
too moist.
Slugs - They love moist
greenhouses and tender growth to raise their young.
Look under the pots as
well.
Thrips- Small, narrow-bodied,
yellow, brown or black insects seem to be
smothering the plant. Shoots and flower buds are damaged. / Too warm or too little
water, not common in the PNW.
White Flies- Under the leaves, small white
eggs are laid- leaves become sticky.
When the plant is touched, little, white flies scatter frantically into the air.
Yellow leaves- The plant is lacking magnesium.