Disease and Pest Control of Hosta

Hosta sunburn

symptom

Hosta prefers semi-shaded and humid environment and cannot be placed in the sun. When exposed to strong light, the leaves may become thinner and yellow at best, or dry up and develop spots on the edges at worst. This phenomenon is called sunburn, a physiological disease.

Solution

This is easy to solve. Just don't place it under strong light. Place it under the shade of a tree or on the north side of a building to avoid strong light.

Hosta Anthracnose

symptom

Anthracnose mainly harms the leaves, petioles and flowers of hosta. Many spots appear on the leaves. As the disease worsens, the spots will gradually break and fall off, forming holes. The leaves will dry up, and the petioles and pedicels will turn brown.

Solution

① In late autumn, remove the withered leaves, be sure to clean them up, remove diseased leaves in time, and take shelter from rain during the rainy season.

② Spraying medicine: When the disease occurs, spray 800 times of 70 % thiophanate-methyl solution, once every 10 days. The number of sprays can be appropriately increased depending on the condition of the disease.

Hosta leaf spot

symptom

Leaf spot disease mainly harms leaves, and often occurs on the tips or edges of old leaves. In the early stage, many small chlorotic spots will appear, which will gradually form large spots. In severe cases, the entire area will dry up.

Solution

① Strengthen management: apply more fertilizer to cultivate strong seedlings; reduce rain and water at the right time; ventilate more and lower the temperature. Pay attention to timely removal of diseased and residual bodies.

② In the early stage of the disease, clean the diseased leaves in time, mix Bordeaux mixture with 0.1% sulfur powder in the ratio of 1 : 0.5 : 200 , spray once every 5 to 7 days, and spray 2 to 3 times in total.

Hosta gray spot

symptom

Mainly harms leaves. The spots are small in the early stage with dark red edges, and a light gray mold layer appears in the later stage.

Solution

① Thoroughly clean up the diseased plant remains around the potted plants to reduce the source of infection.

② When watering, be careful not to water from above the plant to reduce the spread of pathogens through splashing water droplets.

③When the disease occurs, spray 1% Bordeaux mixture to kill bacteria in time.

Main pests of hosta

The main pests of hosta are snails, aphids and whiteflies.

Solution

① If snails appear on the plants, apply 6% of Methida by spreading it.

② If aphids and whiteflies appear on the plants, spray the leaves with 2,000 times diluted 10% aphid killer.