Coneflowers wilting and drying up

(Question)

Hello, why are my coneflowers are wilting and drying up. I’ve attached a photo. It seems to be happening section by section as you can see some stems are still fine. I live in Scarborough. They’re planted in a flower bed at front of house where they get full afternoon sun, sandy soil, quite dry as they’re under the front window which has an awning. I water every other day, I’ve fertilized with MiracleGro and there’s mulch to help keep the soil moist. Thank you.

(Answer)

Thanks for contacting us and including an excellent photo of your coneflowers [Echinacea purpurea].

It seems that the affected coneflowers may have powdery mildew, a fungal disease. This disease occurs in overly moist conditions and/or when there is a lack of airflow around the plants. Judging from your picture, that seems to be the case–plants are somewhat congested. Given your dry, sandy soil, the mulch would help to keep the soil moist; however, watering every other day may contribute to creating moist conditions in which fungal diseases thrive. (We’ve also had periods of ample rain, although the awning may be preventing rain to water the area).

Removing the diseased plants will open up the area to provide better air circulation. And monitoring the moisture in the mulch/soil will hopefully prevent the fungus from spreading farther. Is the soil moist? If so, minimize watering–it’s best to water deeply and not so frequently–once the soil is moist, the mulch will help to retain the moisture in the soil. Furthermore, the moist mulch may be harboring the fungus and contributing to its growth and spread.

What type of mulch are you using? If you use compost or leaf mould (composted leaves) as mulch, there would be no need to use a fertilizer such as MiracleGro. Too much fertilizer can promote too much growth which may weaken the root system of the plants. The best time to use something like MiracleGro would be in the early spring.

Nevertheless, if you remove the diseased coneflowers, monitor the moisture level in the soil before watering, and make sure there is adequate air flow among the remaining plants, the problem should clear up.

July 26,2021