Geraniums are some of the most popular summertime blooms. Propagating and growing geraniums requires extra care. Geraniums are susceptible to several bacterial and fungal diseases that can cause poor plant health and reduce your profits.

Phyton Corp is your partner for broad-spectrum disease control for bacterial and fungal geranium diseases. Our flagship product Phyton 27 is safe to use during propagation and throughout the life of the plant, including on open blooms. Let’s take a closer look at the types of geranium diseases and how to prevent and treat them.

Common Geranium Diseases in Greenhouse Plants

Geraniums are especially susceptible to Xanthomonas bacteria as well as the Botrytis genus of fungus and fungi in the order Uredinales, which causes rust.

Xanthomonas Bacterial Leaf Spot

Xanthomonas is the common cause of leaf spots on geraniums. These bacteria cause small, water-soaked lesions on leaves that are tan to dark brown. Some may have a yellow halo. They are often located along leaf veins.

Protect your geraniums from bacterial leaf spot with diligent sanitation and scouting practices. Minimizing splashing and reduce leaf wetness. Leaf spot can also spread through infected cuttings, seeds, and cutting instruments.

Botrytis Blight

Botrytis blight presents a threat and a challenge in each geranium production phase. Also known as gray mold, Botrytis blight typically thrives in wet, humid conditions. It can affect the geranium’s stems, buds, flowers, and leaves. They develop soft, brown spots that may be covered with a gray mold.

Protect your geraniums from Botrytis blight by following strict sanitation and air circulation practices. Allow plants to dry quickly after watering.

Rust

Rust is a common fungal disease that affects geraniums. It will first appear on the underside of leaves as small, yellow spots that develop brown pustules in the center. A second ring of pustules will then develop. Eventually, these rings push through the leaf and are visible on the upper surface. When this happens, leaves may become yellow and drop off.

Rust spreads by splashing water, air, and workers handling infected plants. Protect your geraniums with strict sanitation practices and good air circulation.

Geranium Disease Control During Propagation

Propagation is a particularly risky time for geraniums, and sanitation is key to protecting your plants against bacterial and fungal disease. Start with stock plants that are free of major bacterial, fungal, and viral diseases to guarantee a healthy crop.

Use Phyton 27 to Control and Prevent Geranium Diseases

Phyton 27 is a versatile, broad-spectrum bactericide and fungicide that is safe for use on geraniums. Phyton 27 can be applied as a spray, soil drench, fog, dip, injection, or chemigation. Here are a few tips for controlling bacterial diseases in established geraniums and during propagation.

Xanthomonas Bacterial Leaf Spot Control

• Apply to stock plants before taking cuttings to prevent disease spread.
• Apply at transplant time to full bloom. Phyton 27 is safe and effective at all stages of geranium growth.
• When symptoms are visible, use 5 ounces of Phyton 27 per 10 gallons every 3 to 5 days.
• As a preventative, use 1.5 to 4.5 ounces per 10 gallons every 10 to 14 days.

Botrytis Blight Control

• Apply to stock plants before taking cuttings to prevent disease spread.
• Apply at transplant time to full bloom. Phyton 27 is safe and effective at all stages of geranium growth.
• When symptoms are visible, use 2.0+ ounces of Phyton 27 per 10 gallons every 5 to 7 days.
• As a preventative, use 1.5 to 2.0 ounces per 10 gallons every 10 to 14 days.

Rust Control

• Apply to stock plants before taking cuttings to prevent disease spread.
• Apply at transplant time to full bloom. Phyton 27 is safe and effective at all stages of geranium growth.
• When symptoms are visible, use 2.0+ ounces of Phyton 27 per 10 gallons every 5 to 7 days.
• As a preventative, use 1.5 to 2.0 ounces per 10 gallons every 10 to 14 days.

Propagation

• Spray stock plants with Phyton 27 a few days before taking cuttings.
• Treat cuttings by dipping them for a few seconds before sticking or spray the stuck cutting a few days after transplant.

Phyton 27 is your best solution for safe, broad-spectrum bacterial and fungal disease control in geraniums. For more information about Phyton 27 and other greenhouse sanitation solutions that are safe for geraniums and other ornamentals, visit phytoncorp.com.