*Common Rose Problems

When using any of the chemicals listed below, always be sure to read and follow all of the manufacturer’s directions before application. Some rose varieties are sensitive and can suffer from some temporary leaf damage due to the application of chemicals or oil sprays.

Spider Mites

spider_mite

Tiny microscopic spider-like pests that suck juices from the plant. Cause a stippling effect or webbing on the undersides and/or tops of leaves.

Some remedies include:

  • Neem Oil (Rose Defense)
  • Bonide All Seasons Spray Oil (Apply only in cooler weather. Some varieties may experience some temporary leaf drop)
  • Orthonex
  • Bayer 2-in-1 Systemic Rose & Flower Care
  • Bayer Systemic All-in-One Rose & Flower Care
  • Hose off with water

Aphids

More than 100 soybean aphids collect on the underside of a soybean leaf. Pest feeding can inhibit the plant's ability to make grain, or kill it outright.

Tiny green, red or black insects that suck plant juices. Generally they are seen on the tips of the tender new growth or on flower buds. They can distort the new leaves and spread viruses.

Some remedies include:

  • Neem Oil (Rose Defense)
  • Bonide All Seasons Spray Oil (Apply only in cooler weather. Some varieties may experience some temporary leaf drop)
  • Safer Insecticidal Soap
  • Malathion
  • Bayer 2-in-1 Systemic Rose & Flower Care
  • Bayer Systemic All-in-One Rose & Flower Care
  • Hose off with a strong jet of water
  • Ladybugs and other predatory insects

Rose Slug

rose_slug

The larval form of the adult Sawfly. The upper or lower surfaces of the leaves are eaten between the veins leaving a lacy, translucent layer of tissue that turns brown.

Some remedies include:

  • Greenlight Lawn and Garden w/Spinosad used to control the larva.
  • Sevin to control hatching pupae.

Powdery Mildew

powdery_mildew2

A white powdery fungus that can distort leaves and flowers. Usually occurs in spring or during periods of low clouds or humid weather.

Some remedies include:

  • Planting roses in full sun
  • Hose off with water in the mornings
  • Immunox Fungicide
  • Neem Oil (Rose Defense)
  • Bonide All Seasons Spray Oil (Apply only in cooler weather. Some varieties may experience some temporary leaf drop)
  • Bonide Lime-sulphur spray fungicide
  • Ortho Rose Pride (formerly Funginex)
  • Bayer Systemic All-in-One Rose & Flower Care

Rust

rose_rust

A fungus that causes rust-colored spots underneath leaves.

Some remedies include:

  • Avoid over-head watering
  • Stripping infected foliage from canes
  • Immunox Fungicide
  • Neem Oil (Rose Defense)
  • Bonide Lime-sulphur spray fungicide
  • Ortho Rose Pride (formerly Funginex)
  • Bayer Systemic All-in-One Rose & Flower Care
  • Watering early in the morning

Black Spot

black_spot

Most common in areas with moist and humid summers. Small black spots appear on leaves which then yellow and drop.

    Some remedies include:

  • Neem oil (Rose Defense)
  • Stripping canes of infected foliage
  • Immunox Fungicide
  • Bonide Lime-sulphur spray fungicide
  • Ortho Rose Pride (formerly Funginex)
  • Bayer Systemic All-in-One Rose & Flower Care

Downy Mildew

downy_mildew

Before the incredible rains of early 2005, most of us had never experienced Downy Mildew. This was a disease that was more prevalent on the coast or areas that have substantial rainfall. Downy Mildew is an air-born fungus. Leaf symptoms include purple-brown spots that resembles Black Spot. The leaves may then turn yellow and drop off rapidly. The fungus is most active when humid weather conditions persist (over 85% humidity and 55-65 degrees).

  • Reduced incidence is achieved by lowered humidity, a rise in temperature and a preventative application of fungicide. Since temperature and humidity can not be controlled, a regular application of the fungicide, Monterey Aliette, is recommended
  • Neem Oil (Rose Defense)
  • Keep rose beds clean of leaves, debris and clippings
  • Air circulation is important when choosing a site for your rose garden
  • Avoid overhead watering