By Bob Westerfield
University of Georgia

The muggy heat makes working in the landscape less appealing than
it was in the spring. But insect, disease and other plant
problems need attending to.

To keep your landscape looking its best, be a Sherlock Holmes in
your yard. Frequent visits to keep an eye on things is often all
you need to detect problems before they get too big.

A trowel, a white index card and perhaps a hand pruner will help
you with your landscape detective work.

First, visit your annuals or herbaceous perennials. These plants
usually need the most immediate attention. Are they healthy,
green and strong or spindly, yellow and weak? Perhaps they need a
little fertilizer. Annuals, in particular, benefit from light,
frequent applications.

Look closely

Be careful, though. Look closely. Yellowing of these plants can
also mean too much water, and recent rains have kept the soil
fairly wet.

Dig down a little to see how wet the soil is and how well it’s
draining. Heavy, wet soils can play havoc on many landscape
plants and may be hard to remedy without renovating the bed.

Look at the blooms of these plants. Deadheading, or removing
spent flowers, will help keep them blooming all summer. Check the
blooms, too, for signs of insects or disease.

Look carefully at the foliage on all plants. Are the leaves
spotted or riddled with holes? Are they speckled, bronze-colored
or different from the way you remembered?

Leaf spots

Leaf spots can be caused by insects or disease. Usually, if it’s
disease, a yellow or purple halo will be around the dark spot.
You may need to use a fungicide. Sometimes, improving the air
circulation by lightly pruning will improve a plant’s health, too.

Insect damage may appear as solid, blackish-brown spots, chewed
areas or speckled leaves. Be sure to look at the undersides of
the leaves. Many insects will feed and hide there.

Properly identifying the insect is the key in selecting the
correct control. Remember, there are far more beneficial insects
out there than bad guys. Beneficials do an outstanding job of
keeping damaging insects at bay on their own.

Buy a good insect-ID book and learn how to tell the good bugs
from the bad. Treat plants only when pests are causing more
damage than you can live with.

Hard to see

Some insects are so tiny they’re hard to see. This is where your
white index card can help. If you see speckled or off-colored
foliage and suspect insects but can’t see any, shake the leaves
briskly over the index card. You may see tiny red specks called
spider mites.

Spider mites can build up heavy infestations quickly if
conditions are right. To control these pests, use a product
labeled for mite control.

Check azaleas for off-colored foliage, too. A common summer
problem is lace bugs, which feed on the undersides of the leaves
of azaleas, cotoneasters and other plants. They have many
generations of offspring, so keep a watch and control this one
all summer.

Chewing damage

Chewing damage on leaves often indicates another type of insect
damage. This can be caused by many insects, including Japanese
beetles, leaf beetles, snails and slugs.

Once you know which culprit is munching on your plants, select
the appropriate control. Insects are usually easier to kill when
they’re young than when they’re mature.

The University of Georgia Extension Service office in your county
can help you figure out what caused your landscape problem and
the best control measure.

County agents have special diagnostic tools and resources to help
them solve almost any landscape problem. Be sure to describe the
damage accurately.

Better yet, bring in a fresh sample. While you’re at the county
agent’s office, pick up a few of their many brochures on insect
and disease control in the landscape.

(Bob Westerfield is an extension consumer horticulturist with
the University of Georgia College of Agricultural and
Environmental Sciences.)