High fever, nausea and headaches are all signs that a person is ill. If
you pay attention
to the signs, your landscape plants will let you know
when they're sick, too.
"Plants put out symptoms just like humans do," says Todd Hurt, a
landscape specialist with the University of Georgia Center for Urban
Agriculture. "You have to learn to be a landscape detective and pick up
on the clues your plants are leaving you."
A former Cooperative Extension agent in Florida and Georgia, Hurt has
done his share of plant detective work. He finds that most plant
problems "are rarely the result of a single factor."
|Ask a few
When diagnosing problems in your home landscape, Hurt says to ask
yourself a few questions:
- Is more than
one plant species damaged?
- How many
plants are affected?
- Is the damage
on all the plants or is it
- When did you
first notice the problem?
- Have you
recently applied a pesticide, herbicide or
an insect attacks a plant, it is usually attracted to a specific
plant species. "You won't see an azalea pest hop over and feed on a
boxwood," he said.
or bottle 'em
If you find an insect on your plant, save it in a bottle of alcohol and
take it to your county Extension agent for identification. If your pest
is a caterpillar, preserve the critter first.
"If your wife is willing to let you use the family stock pot, blanch
the caterpillar briefly in hot water before placing it in a vial of
rubbing alcohol," Hurt said. "This will preserve the color until you
can get to your county agent."
Plant leaf samples should be placed in a ziplock bag and kept cool
until your county agent can identify the problem, he said.
“Do not add water to the bag,” Hurt said.
“Extra water will cause the sample to rot.”
Root samples should be placed in a separate bag to avoid
cross-contamination of soilborne diseases.
If you think your plants have been infected by a plant disease, take a
sample before you spray a fungicide.
“If you take a sample after you spray, you could actually
mask the disease,” he said. “If at all possible,
wait until after you confirm the problem with your county Extension
office. Most plant problems can be corrected without the use of
Plant diseases move through a landscape progressively. "They will start
in one area," Hurt said, "and gradually move to all the plants."
You can diagnose a plant problem, too, by looking at where the plant is
affected. "If the entire plant is brown, you're most likely dealing
with a root problem," Hurt said. "If it's just on the new growth, you
know that you've discovered the problem quickly."
|Don't rule out
Yellow leaves can show that your plant needs more water, he said. On
the other hand, Hurt has seen plant leaves turn yellow as a result of
"I once got a call from a man who wanted to know how to treat his
plants for yellow leaves," Hurt said. "All of the plants along one side
of his home had turned yellow. After looking at the plants and talking
with him, I figured out his plants were actually suffering from the
effects of the bleach he used to pressure-wash his house. No pesticide
or herbicide was going to cure them."
If the damage is distributed evenly across your entire landscape, the
cause is likely environmental, he said.
Environmental factors that affect plants also include cold or drought
damage or, as in the case of the bleached plants, damage caused by
humans, he said.
Another case Hurt solved involved burned leaves."It wasn't drought or
lack of water," he said. "The leaves were burned by the sheets of black
plastic he placed on the plants to protect them while he painted the
Source: Sharon Omahen, University of Georgia
Philosophy of Vegetal Life
Induced Resistance for Plant
Plants and Seeds