What Is Wrong With My Sage Herb?

Are there any galls of various sizes on roots and root crown below the soil line?

Are there any small, dusty, bright orange, yellow or brown pustules on undersides of leaves?

Are there any dark spots on leaves that turn brown to gray, lesions may be round or angular and may possess a purple-black margin?

Are there any small, angular, gray-brown spots with defined red-brown margins on leaves?

Are the seedlings dying and the stems are girdled or rotted at soil line?

Are the leaves covered with white powder?

Do the leaves have large, ragged holes in them?

Are the leaves curled and yellow?

Are the leaves distorted, yellowed, and stippled?

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

Crown gall is a bacterial disease that enters through wounds on the plant. Plant only disease-free seeds purchased at a reputable nursery. Plant sage in well-draining soils. Avoid wounding the plants as much as possible.

Mint rust is a known fungal disease that attacks oregano. The disease also affects mint and can spread from nearby mint plants. Infected plants and rhizomes should be removed to prevent spread. Heat treatment of roots may help to control the disease, roots should be immersed in hot water at 111°F for 10 minutes, cooled using cold water and then planted as usual.

These symptoms indicate Alternaria leaf spot. Warm, wet conditions favor this fungal disease. Spray infected plants with copper and/or sulfur to prevent further disease development. Plant only pathogen-free seed from a reputable nursery.

These symptoms indicate fungal disease - Septoria leaf spot. This disease overwinter on old leaf litter, so rake up the leaves or bury them under a thick mulch in autumn. Copper sprays will help in controlling the spread. If defoliation occurs late in the season, it does plant little harm.

If your seedlings are falling over and the stems are girdled or rotted at the soil line, the most likely cause is a damping-off disease. Remove and destroy all infected plants. To prevent damping-off let the soil surface dry between waterings, thin seedlings to avoid overcrowding and do not add nitrogen fertilizers until plants have developed leaves.

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 bellow to keep foliage dry. Any affected leaves should be cut off and removed.

Large, ragged holes in the leaves are caused by slugs and snails. Slugs and snails feed on the plant leaves usually at night. To control slugs and snails use diatomaceous earth around your plants. You can also handpick them during the night or use shallow dishes filled with beer as a trap.

Distorted, curled leaves are caused by aphids. These tiny insects cluster under leaves and on growing tips where they feed on plant sap. Leaves, stems, and buds get distorted, and later leaves and flowers drop from the plant. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

Leaves stippled with yellow are caused by mites. These tiny, spider-like pests feed by sucking sap from the underside of the plants leaves causing yellow flecking on the upper leaf surfaces. 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 may indicate thrips. Thrips are tiny, yellow to black flying insects. 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.

Spittlebugs will sometimes attack sage. The insect produces a protective foam that looks like spit. The foam helps protect the insect from ultraviolet light, predators, and insecticides. Use a strong spray of water to wash the foam away. The resulting exposure to UV light will kill the insect and expose it to predators. A stronger spray of water may also remove the insect from the plant.