Irish Moss Diseases & Insects

Fungal Diseases

• Fungus attacks Irish moss when moist conditions are present. Too much water in the ground causes fungi to gain access through the roots of the plant. Portions of the plant turn brown, die and spread through the entire plant. Other types of fungus attach and spread through Irish moss when aphids are present. It appears as a sooty black mold on the leaves that prevents the leaves from performing photosynthesis, thus killing the plant.

Slugs and Snails

• Slugs and snails are a problem because the dense mat of Irish moss provides a place that is cool, moist and out of the sun's rays. Slugs and snails enjoy this type of atmosphere and they are right at home, chewing holes in the leaves and gnawing off whole portions of the plant.

Aphids

• Aphids are small brown to green insects that come with or without wings. They attach themselves to a plant and drain it of its life-giving juices. Leaves curl, turn yellow and die while a sticky substance, called honeydew, covers other leaves and sometimes drips to the ground. A severe aphid infestation can allow fungus to invade the plant and cover the leaves with black mold.

Controls

• In most cases, fungal-infected Irish moss must be removed. Prevent fungal infections by planting Irish moss in an area that is well-drained, which will also control slugs and snails. Control aphids to avoid the type of fungus that attacks during an infestation. Irish moss is not a true moss that thrives on moisture. It prefers dry roots and rich soil.
  Control slugs by handpicking at night and tossing them into a bucket of soapy water. Place beer in a shallow container dug into the ground so that the rim is even with the soil line. Slugs and snails will crawl in and drown.
  Mix 1 teaspoon of vegetable oil, 1 teaspoon of dishwashing liquid and 1 cup of water. Put it in a spray bottle and spray it on the plants on top and underneath. The solution blocks the breathing mechanism of the aphid. Leave the solution on for a few hours and rinse it off to prevent sun scald. Ladybugs are another alternative because they eat aphids.