Home Remedies & Natural Answers to Pest Problems
Roses may attract certain insect pests or foliar diseases, especially during cool, wet weather. Many problems can be managed with cultural controls before they get out of hand (prune infected leaves or physically remove pests). If, however, you are losing the battle, try these environmentally-friendly alternatives to pesticides. Many of these solutions require more frequent application to achieve control, but do not pose significant health risks like traditional chemicals. As an added benefit, they are generally inexpensive to prepare! Don’t forget to spray the underside of leaves as well as the upper surface during application.
Aphids, Mites, Scale & Whiteflies
Orange Oil Cleaner – Dilute 1 teaspoon per gallon of water. Use when needed (apply to leaves). Good coverage is important; wet leaf surfaces to point of drip.
Soap Spray – Mix ½ teaspoon mild dish soap and 1 teaspoon cooking oil to a 1-quart sprayer filled with water. Spray liberally over entire plant.
Bring in Ladybugs – To keep aphids in check, release on the affected plant. They will stay as long as there is shelter and host bugs to feed on. Aphids may also be dislodged by a strong jet of water.
Slugs & Snails
Beer – One inch in bottom of an empty tuna or cat food can. Set in garden. Slugs and snails are attracted to the yeast in beer and essentially drown.
Handpick – Collect them at night and remove from the garden area.
Coarse Sand, ¼”-minus Gravel or Hazelnut Shells – Apply sand or gravel in trails around roses, or topdress beds with crushed hazelnut shells (slugs and snails prefer not to cross abrasive surfaces).
Powdery Mildews, Blackspot & Rusts
Baking Soda Spray – Mix 1 tablespoon baking soda and 1 teaspoon cooking oil in one gallon of water. Place in spray bottle or tank sprayer and apply liberally (repeat as needed).
Sanitation – Remove infected leaves and destroy. Keep the ground surrounding your roses free of leaf debris and weeds.
Cold Water – For Powdery Mildew, spray affected leaves with cold water early in the morning and allow sunshine to dry off.
Leaves fall when tapped = Too much water.
Leaves stay on when tapped = Too dry.
Crunchy leaves = Too dry and too late. Cut back as needed and let grow back.
Exceptions: Some rose leaves turn yellow in the fall. This is normal coloration.
Aphids reproduce rapidly and like tender new growth
Spider Mites are found on the undersides of leaves and may cause stippling damage
Slug damage on rose leaves
Black spot spreads by rain or overhead watering and may cause leaf drop if untreated