This is the first year I've had problems with mites - on my
brugmansia. Just like your article says, the leaves became pale &
yellowy & then started dropping off. I tried insecticidal soaps, but
then switched to simply hosing the plant thoroughly. This not only
washed them off, but also increased the humidity. Is there any was
to prevent these tiny critters from coming back?
In My Garden Blog
Coastal and Tropical South
August 13, 2009
By
Nellie Neal,
Baton Rouge, LA
Lantana infested with spider mites soon attracts other opportunistic pests.
Late Summer Pests
I was once asked to explain the difference between organic gardening in the South and elsewhere. I concisely explained that we live where the soil never freezes and the bugs never die. The interviewer, a brilliant Yankee, gasped audibly. At this time of the year we have multiple generations of some pests, and new arrivals, too.
Crispy Lantana
Lantana and spider mites share a mutuality that benefits only the mites. Both are best grown in hot, dry conditions, but the lantana gets badly abused when they find each other. By this point in the season, the mites have multiplied geometrically and the damage is done. Leaves get pale and may look stippled, then the leaves begin to die slowly as they are sucked to death by the mites. The leaves respond by drying up and sometimes changing colors, showing yellow or white patches or even a burnished tone. The plants stop flowering and the scene is ruined. Cut down the lantana, clean out all the debris, and do not compost it or risk creating a source of future infestation. In future dry spells, spray water under the leaves of the lantana weekly to keep the mites at bay.
Lawn Invaders
Both fungus diseases and chinch bugs find August accommodating, depending on the weather in your area. Wet summers fuel brown patch and take all root rot, two serious pathogens that are also encouraged by excess nitrogen fertilizers. Keep the lawnmower clean, mow at the recommended height, and consider a fungicide if the patches are consistently large and in the same part of the lawn. Chinchbugs also create browned lawn areas, but are more troublesome in dry summers. Granular insecticides can control them, and fall is a good time to replant ruined areas. Test before you invest time and money, to be sure chinchbugs are to blame: take both ends off of a can, sink it into the area where browned turf meets green, and fill it with water. Chinchbugs are half-inch, cigar-shaped bugs that will float to the top.
Webworms
One day your trees look fine, the next their leaves are stripped and a brown web forms in the branch crotch. Luckily, common webworms are more trouble to you than they will be to a mature tree. Young trees suffer more when any of the few leaves they have are eaten, so it is wise to consider control measures. It may sound silly, but a broom wrapped in cheesecloth is the perfect weapon for this hunt. Poke the broom into the web and twist it around. The cheesecloth picks up the sticky webs so you can get them out of the tree. If the problem is severe this year, watch it closely next summer for the first sign of tiny caterpillars feeding. Spray the tree with neem or another insecticide at intervals as directed on the label. Stop the feeding, stop the webs.
Good Arrivals
Of course, some of summer's insect guests are decidedly good guys and gals. If you are unsure whether a critter is a pest or if a spot on a leaf means trouble, do some troubleshooting before you start spraying. And when you do spray, target the insect, mite, or disease and the particular plants that are being damaged. No wholesale spraying!
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Comments on Late Summer Pests
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Mites in the Garden
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Liz
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The best way to keep mites from overtaking the garden is to let
nature do its job. I let accidental plants grow in amongst my
cultivated plants; I never use insecticides OR herbicides; there are
lots of lizards, wasps, frogs, and toads in my garden (lizards,
frogs, and toads are vulnerable to herbicides as well as
insecticides.) The combination of native plants (which provide
amble forage for what we call pests), and predatory animals keeps
massive outbreaks from happening in my yard. And I don't sweat the
small stuff.
Nellie
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Your strategy of wetting the plant is exactly what the mites hate,
and if you disrupt their environment regularly, they'll have a tough
time getting established. That not only cuts way down on the damage
to your plants, it makes them more vulnerable to the predators
mentioned in the previous comment. Prune harder this year, clean up
all the debris, and keep misting in dry weather, especially under
the leaves. This is a place for one of those 'sprinkler hoses' that
doesn't just soak, it sprays a few inches up, too.
DeEtte
I HAVE PROBLEM WITH RACOONS IN MY CORN . THIS YEAR I MADE A PEPPER
SPRAY WITH HARBANARO AND LET THEM SOAK IN A 5 GALLON BUCKET FOR 2
DAYS THEN I PUT IT IN A SPRAY BOTTLE AND SPRAYED ALL MY PLANTS. THE
WORMS WERE NOT EVEN ON THE BROCCOLI.AND I HAD CORN THIS YEAR.
AMAZING!!!