What is wrong with my trilliums?

Are there any small, circular red lesions with a distinct margin develop on leaves and stems, lesions may enlarge during humid weather conditions?

Are there brown to black spots or blotches present on the leaves?

Are the leaves pale on their upper side and are there any dusty blisters on the undersides?

Do the leaves have large, ragged holes in them, mucous trails may be present?

Is the head replaced by a brown, powdery mass of fungal spores covered by gray to brown membrane?

These symptoms indicate a fungal disease - Anthracnose. Disease emergence is favored by wet conditions. The fungus is spread by splashing water. Keep plants dry when watering to prevent spread. Spray plants with copper when the first pods develop if you have had problems in the past.

Leaf spot diseases are caused by several fungi that thrive on moist leaf surfaces. Brown to black spots develops on the leaves of infected plants. These spots often come together to form larger patches of dead tissue. Pick off and discard infected leaves, and spray the vine foliage every seven to ten days with sulfur. Avoid wetting the foliage while watering the vines. Mulching around plants helps prevent fungi from being splashed up from the ground by rain.

Likely cause for these symptoms is a fungal disease - Rust. Provide good air circulation around plants by thining them. Avoid making leaves wet when watering. All infected leaves should be removed. Spray leaves with sulfur early in the season to prevent rust or to treat mild infections.

Large, ragged holes in the leaves are caused by slugs and snails. Slugs and snails feed on the plant leaves usually at night. To control slugs and snails use diatomaceous earth around your plants. You can also handpick them during the night or use shallow dishes filled with beer as a trap.

Smut is a fungal disease promoted by cool, dry soils. The entire head may be affected by the fungus or it may be localized at the top, bottom, or sides of the head. The disease can be prevented by growing resistant varieties or controlled with the application of appropriate fungicides.

Mineral deficiencies can cause tip chlorosis or necrosis or cause foliage to discolor, fade, distort, or become spotted, sometimes in a characteristic pattern that can be recognized to identify the cause. When nutrient deficiencies occur, nitrogen and iron are the most commonly seen deficiencies. Apply only the mineral found to be deficient. Excess nutrients, on the other hand, cause symptoms like leaf tip dieback, marginal leaf chlorosis, necrosis (or burn), branch dieback, and pest problems. In this case, you should provide good drainage, and use good practices during fertilization and irrigation.