Identifying and Treating ‘Fire Blight’ In Roses

Fire blight (Erwinia amylovora) is a relatively common infectious disease that targets roses, pear trees, and apple trees. Early symptoms of the disease typically include brown-colored cuts and lesions – where the bacterium entered. If left untreated, the fire blight can kill its host while spreading to other nearby plants.

Whether your roses are currently suffering from fire blight or not, it’s important for gardeners to familiarize themselves with this disease. While fire blight can prove deadly if left untreated, taking immediate action at the first signs of infection will drastically increase your chances of a positive outcome.

Symptoms of Fire Blight In Roses:
•Shriveled, wilting blossom clusters
•Twigs and shoots begin to blacken
•Brown/dark-colored cuts and lesions
•Reddish-brown steaks running down stems
•Infected shoots bend at the tip; a condition referred to as “Shepherd’s Crook”

Risk Factors of Fire Blight

According to a report published by researchers at the University of Arizona, Fire Blight forms in mild-to-moderate temperatures ranging between 60 and 85 degrees Fahrenheit with a relative humidity of 60% and above.

Under this formula, many regions are safe from Fire Blight with the exception of a few “peak” months during the summer. The report notes, however, the higher elevation, such as mountainous regions, may increase the prevalence of Fire Blight.

How To Treat Fire Blight In Roses

As with most infectious disease, timing is crucial to saving an infected plant’s life. Failure to take immediate action may result in the plant dying, or even worse, the disease spreading to other nearby plants. So, what’s the best approach to treating Fire Blight in roses?

Begin by pruning away any dead, dying and/or infected tissue. Even if your rose bush is not currently suffering from Fire Blight, you should still get into the habit of pruning away dead shoots and leaves. The bacterium responsible for this disease loves to thrive in decaying plant matter, so trimming it away in a timely manner will discourage the disease in your plants.

There are also chemical-based treatment products which have proven to be effective in combating Fire Blight. One particularly effective product is an antibiotic known as Streptomycin sulfate. Agri-Strep and Agri-Mycin 17 both contain this powerful Fire Blight-fighting antibiotic. Applying this chemical to your plants will kill the infection, allowing your plants to revert back to their normal, healthy state.