Plant Doctor Archive

Azalea flowers dying

MY azaleas flower beautifully at first then after about 10-14 days the blooms soften and go brown. I've had this trouble for the past three years and I've tried spraying with fungicide to no avail. This year I fed them with liquid sheep manure and, while the bushes look healthy, it makes no difference to the flowers dying off. Can it be cured?

THERE are several diseases that affect azaleas but it sounds like flower blight is the culprit in your case. It's a fungal disease that affects only the flowers, starting off as spots on the petals but eventually spreading to cause the whole flower to collapse. It is worse during rainy weather when the blooms stay wet for long periods, which also helps the disease spread from flower to flower.

The fungus lives from one season to the next in the mulch and decomposing organic material beneath the bushes, so one way to help break the cycle is to clean this up in winter and replace with clean mulch before the new season's blooms open. When the flowers do begin to open, you could spray with a fungicide such as Bravo or Greenguard, according to the label recommendations. Spraying every 10 days or so during the flowering season should help control the disease and, along with clearing up the debris under the bushes, the severity of infection should be a lot less next year.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.