Identifying coneflower problems, such as diseases or deficiencies, is important in order or keep your plant healthy or to keep your plant in general. Some conditions of your coneflower can be easily treated or go away on their own, others require extensive treatment.
The most important thing to remember is that, by keeping your plant healthy, keeping it watered, fertilized and free of pests and damage, it won't be easy for your coneflower to have problems. Simple plant upkeep will save you money and time in the long run. However, if you take good care of your plant and problems still pop up, no worries! Many illnesses are easy to spot and treat.
If you notice a bad smell coming from your plant or its root system, rot is likely the problem. Root rot is a major problem in commercially produced coneflowers and a common problem in your home landscape. The disease will usually appear in the plant's second year.
The root system provides water and nutrients to the plants so you will see an overall sick look to the plant. There isn't a cure for fusarium root rot. A fungicide drench can help prevent the disease from spreading and acquiring more infections, but the only cure is removing the plant, destroying it and sanitizing the soil.
Mottled leaves without any visible textural changes usually hint at a mosaic virus. Cucumber Mosaic Virus can occur in Coneflowers and has numerous and variable symptoms, making the cause difficult to determine, at times. If you have noticed mottling of the leaves of your coneflower, it is a good idea to send a sample in to your local plant pathology lab.
If CMV is confirmed and you'd like to keep your infected plants, they must be removed from all other plants as the virus spreads easily. If you want to protect your plant ahead of time, though, treat the plant with an insecticide or organic equivalent as the virus is often transferred by aphids. Certain weeds can also bring the virus in close proximity to your coneflower, so make sure your landscape is weeded often.
Textured Spots in Leaves
If you see spots on your coneflower leaves that have a noticeable texture and color, your plant likely has a fungal infection. One of the most common fungi of coneflowers is Powdery Mildew. It looks just how it sounds—as if white powder has been dusted over spots of your leaves. The fungus will be noticeable while leaves still look somewhat healthy. Rather rapidly, the areas with the fungus will decline, turning different colors and may also dry out the leaves, making them very brittle.
Luckily enough, powdery mildew is treatable. If you notice it only on a few infected leaves, you can clean the fungus off the leaves (don't forget to sanitize). For wide-spread infection, apply an insecticide for coneflower plants. Insecticides are highly effective with powdery mildew. If you'd like to make your own spray, there are numerous places to find recipes. You can even mix garlic and water to act as a sulphur fungicide spray.