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Articles listed under “disease”

Rust — October 13, 2009

You’ll spot powdery rust, orange or brown spots, like these on a snapdragon, on either side of the leaf.

Crown rot — September 8, 2009

Crown rot affects hosta, bleeding heart, phlox, daylily and many other perennials.

Cedar-apple rust — August 18, 2009

In fall, you’ll spot hard brown galls on twigs of Eastern red cedar. In spring the galls swell, turn orange.

Hosta virus X — July 7, 2009

Unusual leaves, like the one in the photo, could be symptoms of hosta virus X (HVX).

Blackspot on roses — June 2, 2009

In spring small black spots appear on the leaves, and occasionally the stems, of roses.

Powdery mildew — May 12, 2009

The white granular patches look like dust on the stems, the tops and bottoms of leaves and occasionally on flowers and fruit.

Anthracnose — April 14, 2009

When anthracnose strikes after a cool, wet spring, you’ll find irregular dark blotches on leaves.

Botrytis gray mold — March 24, 2009

Botrytis gray mold appears as small, wet-looking spots, usually in spring, on tender new flower buds and blossoms.

Fire blight — February 24, 2009

This aptly named infectious disease makes a tree look scorched, with leaves and stems withered to brown or black.

Aster yellows on coneflower — January 13, 2009

One disease that can infect purple coneflower is aster yellows. It’s caused by a phytoplasma, a disease-causing organism smaller than bacteria but larger than a virus.

Daylily rust — November 18, 2008

Like other rust diseases, daylily rust causes orange spots and streaks on the leaves.

Septoria leaf spot — August 19, 2008

Septoria leaf spot is a common fungal disease that can affect black-eyed Susans. It begins with brown-black spots on the leaves.

Blossom-end rot on peppers — August 5, 2008

Blossom-end rot is a common problem with peppers, tomatoes, melons and squash. It starts out as a round, sunken, soft spot at the end of the pepper and grows steadily larger.

Botrytis on peonies — July 22, 2008

Peony bushes can suffer from a variety of fungal diseases and Botrytis is a big one

Verticillium wilt — July 1, 2008

If the leaves of your annual flowers and vegetable plants seem to be yellowing and curling, your garden may be infected with verticillium wilt.

Aster yellows — June 24, 2008

Deformed flowers, yellow foliage and stunted growth are classic signs of this disease. Symptoms vary according to the temperature and the age and type of plant.

Fireblight — November 20, 2007

This aptly named infectious disease makes a tree look scorched, with leaves and stems withered to brown or black.

Blackspot on roses — November 6, 2007

The name says it all. This fungal disease causes black spots with fringed margins and a yellow halo on leaves.

Crown gall — October 9, 2007

A good word to describe crown gall on roses and other ornamental plants is “yuck.” The lumpy growths around the base of the plant are unattractive, to say the least.

Powdery mildew — July 3, 2007

In mid- to late summer, you may notice a gray-white film on a plant, and the plant may begin to lose leaves. The culprit is powdery mildew. You’re most likely to see this problem on roses, phlox, zinnias, bee balm and lilacs.