Extension > Garden > Diagnose a problem > What's wrong with my plant? > Annuals and Perennials > Petunia > Discolored leaves
Petunia > Leaves > Discolored leaves
1 of 4
Aster Yellows
Phytoplasma
- Leaves are small and yellow on a few to all stems
- Flowers are small pale green to white and underdeveloped
- Clumps of weak shoots known as witches broom develop throughout the plant
- Infected plants are often stunted
- Often one to a few random plants within a flower bed are infected while others remain healthy
- More information on Aster Yellows
2 of 4
- - CLICK PHOTO TO ENLARGE -
Two-Spotted Spider Mites
Tetranychus basicola
- Active during summer, particularly abundant during hot, dry weather
- Pale stippling appears on the upper leaf surface
- Leaves are discolored off green to whitish, yellowish, or bronze
- Premature leaf drop can occur
- Visible webbing occurs on infected leaves when populations are high
- Adults are tiny (1/50th inch long) and oval, greenish or yellowish with a dark spot on either side of the body
- More information on Two-Spotted Spider Mites
3 of 4
Powdery Mildew
Oidium sp.
- Powdery, fluffy white spots or blotches on leaves, stems, and flower parts
- Tiny black round spheres may be visible within white spots late in the season
- Spots typically start on lower leaves but can spread to cover the entire plant
- Severely infected leaves may be completely covered in white or grayish white fungi
- In some cases, leaves become curled or twisted or turn yellow due to the infection
- More information on Powdery Mildew
4 of 4
Tobacco Mosaic Virus (TMV)
- Symptoms may vary depending on cultivar, age of plant and other factors
- Leaves have a mosaic pattern of light and dark green
- Leaves may be distorted, curled or twisted upward
- Lab test needed to identify which virus is causing the problem
- More information on TMV
