What Is Wrong With My Redleaf Rose Plant?

Are the flowers covered with gray mold?

Do the leaves and stems have black spots on them?

Are there any rust-colored spots on foliage?

Are the leaves covered with white powder?

Does the crown have swollen, tumor-like growths?

Does the trunk or the branches have sunken areas of dead tissue?

Are the leaves curled and distorted?

Do the leaves and flowers have holes?

Are the leaves distorted, yellowed, and stippled?

Are the leaves covered in coarse stippling and may appear silvery?

Are the leaves covered with small bumps?

Likely cause for these symptoms is a fungal disease - Botrytis blight. Other symptoms include brown to black spots that may appear on leaves and petals. You can only prevent Botrytis blight disease by planting sweet alyssums in areas with good air circulation. Water plants sparsely. Infected plants should be removed. Spray weekly with a copper fungicide until the disease is under control.

Black spots surrounded by yellow patches are caused by fungal disease - Black spot. Prune off and destroy all diseased leaves and clean up all fallen ones. If possible, avoid wetting the leaves when watering. For severe infections, the recommended control is weekly applications of sulfur.

Rust-colored spots on foliage indicate a fungal disease - Rust. Provide good air circulation around plants by thining them. Avoid making leaves wet when watering. All infected leaves should be removed. Spray leaves with sulfur early in the season to prevent rust or to treat mild infections.

White, powdery patches on the leaves are caused by a fungal disease Powdery mildew. Powdery mildew usually appears in damp places. Encourage good air circulation around the affected plants by thining them and any surrounding plants. Water plants from below to keep foliage dry. Any affected leaves should be cut off and removed. The appropriate fungicidal spray will protect your plant from further infections.

Bacterial disease Crown gall causes wartlike swellings on Redleaf rose crowns. Plants can become stunted, subject to drought stress and wind damage. Large enough galls may cause girdling which results in plant death. Avoid injury of the plant. If the plant is only slightly infected, prune off diseased growth. Destroy severely infected plants and avoid replanting tayberries or any other susceptible plant species in the same spot.

Sunken areas of dead tissue on Redleaf roses are caused by cankers. Cankers can be caused by several different kinds of fungi. Mildly affected plants will recover if you remove and destroy all affected branches. Heavily affected plants can't be cured and you should remove the whole plant. Avoid damaging your plant with lawnmowers, trimmers, or pruning tools because the wounds are the best place for cankers to start.

Distorted and curled leaves are caused by aphids. These tiny insects cluster under leaves and on growing tips where they feed on plant sap. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

Holes in leaves and flowers are caused by Japanese beetles, pests that can seriously damage foliage. Handpick adult beetles into a can of soapy water but make sure to wear gloves as Japanese beetles are blister beetles. Apply parasitic nematodes to the soil to limit beetle grub populations. Use pyrethrin powder or neem oil as a last resort.

Leaves stippled with yellow are caused by mites. These tiny, spider-like pests feed by sucking sap from the underside of the plants' leaves. You can control spider mites by spraying plants thoroughly with water 2-3 times a day for several days. For severe infestations, spray plants with insecticidal soap.

These symptoms indicate thrips. Severely infected plant parts should be removed and destroyed. Control thrips by introducing lady beetles or lacewings, their natural predators. Insecticidal soap helps in severe infestations.

Leaves covered by small bumps are caused by scales. Scrape off minor infestations with your fingernail. Prune out badly infested growth, or use a soft brush and soapy water to gently scrub the scales off the stems. Control scales by spraying insecticidal oil during the growing season.

Borers often cause stems of Redleaf roses to die. These pinkish, up to 2 inches long larvae enter the cane on the top and tunnel down. In fall, remove dry leaves as they might carry borer eggs and destroy badly infected plants in spring. In spring you can also dust the base of the plants with pyrethrin to kill emerging larvae.