Why does hostas turn brown

What is happening to my hostas? The hostas may have petiole rot. Petiole rot is a serious disease of hosta. It is caused by the fungus Sclerotium rolfsii var. Petiole rot can also affect daylily, peony, phlox, columbine, and other perennials. Disease symptoms on hosta start as marginal yellowing and browning of the lower leaves. Increase watering so the plant receives at least 1 inch of water weekly, and cover the soil with a 2-inch mulch layer to help conserve moisture. Once the plant recovers, trim out any badly browned and damaged leaves to improve the appearance of the hosta.

The fungus Sclerotium rolfsii var. It's most common in warm, rainy weather. Affected hostas develop brown, mushy areas at the base of their petioles, where the leaf joins the base of the plant. As the disease progresses the edges of the leaves turn yellow, then brown. Heavy mulch against the crown of the plant can increase problems, so pull the mulch back so it doesn't rest against the hosta. Petiole rot is difficult to manage once present. Dig up and destroy infected hostas and do not plant any more hostas in the location for at least three years.

Add organic matter to the soil to improve the water-holding ability of fast draining sandy soils. Water the plants thoroughly and often enough to keep the soil slightly moist. Mulch the soil with shredded leaves, evergreen needles or other organic matter to keep the soil cool and evenly moist. Yes, I know, this also creates the perfect environment for slugs. If a slug problem develops, capture these slimy pests with beer in a shallow can.

Lesions can also travel down to the petiole of the plant. Anthracnose can affect hosta during warm, wet weather. Symptoms appear as large, irregularly shaped, tan to brown spots with dark borders. The centers of the spots can fall out, giving the plants a tattered appearance.