Oxalis Disease

Common diseases and infestations of the Oxalis genus of plants.

The genus Oxalis includes a large variety of plants with a wide set of reputations. Many people have considered the varieties as weeds, while others consider them herbs with healthful benefits. These plants live in a variety of regions and can handle a variety of temperatures.

Puccinia Oxalidis (Oxalis Rust)

This variety of rust appears on the underside of Oxalis leaves. The rust appears as mustard-yellow to light-orange concentric rings. Infected plants can be treated with fungicides and removed from the vicinity of other plants to prevent further spread of infection.

Fungus Gnats

Over-watered Oxalis plants may become susceptible to attracting fungus gnats. The larvae of the fungus gnat require constantly moist soil to hatch and live. The adult gnat will only lay their eggs in moist soil, so allowing the soil of the Oxalis plant to completely dry out between waterings may help alleviate some fungus gnat problems. If problems persist, sprays and insecticidal soaps may solve the problem.

Spider Mites

Spider mites are small, plant-eating mites that can cause severe damage to leaves. They pierce holes into the protective layer of the plant's leaves to extract nutrients from the leaf cells. The leaves will lose water and turn brown due to the damage caused by the mites.

Aphids

Aphids are small insects that feed on the juices of younger leaves. They can deplete a leaf of the nutrients it needs to grow properly, and sometimes curling or deformities may occur. Aphids excrete substances that attract larger insects and provide nutrients for fungal infections that Oxalis are prone to acquiring due to their frequently damp living conditions.

References

• Northeast Greenhouse, IPM Notes, May 2005
• HortChat.com: Fungus Gnats
• Pacific Bulb Society: Oxalis
• Living With Bugs: Spider Mites
• HortChat.com :Aphids