Black Spot- A rounded dark lesion on the foliage that defoliates the plant from the ground up. Leaves often turn yellow before falling. Appears in early summer. Spread by splashing water.
Powdery Mildew- Irregular white lesions that deform the young soft foliage. Appears first in spring. An airborne fungus.
Downy Mildew- Irregular purple-black lesions on canes and foliage. Defoliates quickly. Appears when nights are cool and days are warm.
Rust- Rust-red spots appearing on the undersides of lower leaves. Appears in cool conditions. Spread by splashing water.
Aphids- Soft green insects that suck plant juices from young growing tips and flower buds, producing sweet exudates that often attract ants.
Spider Mites- Very minute arachnids that give a salt and pepper appearance to the undersides of leaves. Can defoliate from the ground up and stop any new growth when severe.
Thrips- Tiny sucking insects that enter the young flower buds and damage the petals,
producing brown edges and streaked and distorted petals.
Beetles- Flying insects that eat large portions of the flowers, buds and often the foliage.
Midges- Soil borne insects whose larvae distort and devour the young flower buds and tips of growing shoots.
Borers- A larvae that enter fresh cuts and bores down the center of the cane.
Caterpillars- Larvae of moths or butterflies that appear sporadically in summer.