Removing the flowers as soon as they finish flowering also helps to keep the garden looking neat and tidy. You can leave some of the seed heads on the plant so it can serve as food for birds during winter. Make sure to deadhead plants before the seed heads ripen if you don’t want them to spread all over the garden. Removing the spent flowers also reduces the rate of self-seeding in the plant. However, some like the Black-eyed Susan must be deadheaded to ensure they grow flowers consistently throughout the season. Some species of coneflowers such as the Yellow and Purple do not require deadheading. It also encourages flower blooming for plants that are not doing well as well as reblooming in a new season. Here is an article I wrote about do coneflowers attract bees? Should You Deadhead Coneflowers?ĭeadheading, or clipping of wilting flowers from a plant, helps to redirect the plant’s energy toward the healthy root and leaf growth instead of seed production. Of course, prevention in the first place is always the best option and the defense against these is to have a healthy plant. Mulching, sanitary habits as well as crop rotation are further methods that can be used to treat these leaf spot diseases. Treatment for these two diseases is often done by spraying fungicide on the plants. You should always watch out for these two diseases and once they have gotten to a serious stage, they can kill the plant.

This location is frequently surrounded by a golden halo.īecause these patches do not travel on the veins, their spread is limited. This disease also has dark brown or black patches just like in Alternaria. The symptoms of this disease differ slightly from those of Alternaria leaf spot disease. Along the midrib of younger leaves, the spots can be observed.īacterial leaf spot, as the name suggests, is caused by bacterial organisms. These spots can sometimes even cover the pores and vines of the plant. After expansion, the centers of the spots become lighter. These develop pale centers and become oblong as they expand. There are two major causes of blackening coneflower foliage and they include Alternaria and bacterial leaf spot diseases.Īlternaria leaf spot begins as tiny black or brown spots on the plant’s leaves.

This means your plant is no longer healthy and has already been infested by a disease. You might have noticed your coneflower leaves changing from green to black in patches.

Purple coneflower turning black