What’s Wrong with My Coneflower?

Several diseases and pest affect coneflowers . While your coneflowers may never get any of them , it can be troubling if they do .

Powdery mildew

This disease typically happen in too damp conditions or from a want of airflow . plant that are already weakened by gadfly or disease may be especially susceptible . Avoid powdery mildew by space plant properly and planting in well - drained soil .

Eriophyid mites

Floral damage have by eriophyid mites mime some of the symptom of aster yellow ( see below ) . In this casing , the damage is only cosmetic and wo n’t touch the health of the plant , although it will reduce seed production . Mites feeding on the flowers make tufted development or little potato to organize on the cone . The malformed blossom are unsightly and similar in visual aspect to aster yellows . Removing the affected flowers will ameliorate the ornamental display and reduce the mite population .

Japanese beetles

The beetles feed on leafage and heyday , leaving ragged holes behind . Fortunately , their equipment casualty is primarily cosmetic . Hand pick adult mallet and disposing of them works best .

Crown / shank rot . Photo : Nova Photo Graphik / gapphotos.com

Crown/stem rot

Normally lead from overwatering ( or from a industrial plant being sited in an excessively moist site ) , tip / prow rot termination in the full plant turn brownish and essentially rotting aside . Again , well - drained grime is primal .

Aster yellows

This is perhaps the most grievous problem because there is no bar or remedy — all parts of the plant life are infective and potentially harmful to other plants . A specialised bacterium called a phytoplasma spreads from plant to institute by leafhoppers , which are sucking insects that feed on coneflower . Disfigured and chlorotic foliage , stunted stems , and deform peak are symptom of aster yellowness . unnatural flowers may also show fleeceable spoonful - shaped rays and/or a rosette of leafy growth on the strobilus ( exposure ) . The phytoplasmas multiply in the base over winter , so symptoms worsen every year . sanitisation is best as soon as symptoms appear — all role of the industrial plant , include the roots , must be destroy .

See more about coneflowers inWhat’s New With Coneflowers?

Richard Hawke is plant evaluation manager at the Chicago Botanic Garden in Glencoe , Illinois .

Photos , except where noted : Danielle Sherry

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