Common sage is a woody perennial herb grown for its gray-green aromatic leaves, used fresh or dried in cooking. In Zone 6b it survives winter and returns each spring, forming a low shrub that can produce for several years before the stems get woody and yields drop.
Sage needs sharp drainage and full sun; it rots in wet, heavy soil. Cut back lightly in spring once new growth appears, harvest leaves regularly to keep the plant productive, and replace plants every 3–4 years when the center turns woody and sparse.
Powdery mildew
White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.
Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.
Sage Root and Crown Rot
Wilting despite moist soil, yellowing lower leaves, blackened soft stems at the base, and brown mushy roots.
Improve drainage and reduce watering. Remove and destroy affected plants. Plant in raised or sandy beds and avoid waterlogged conditions.
Spider Mites
Fine stippling or bronzing on leaves, faint webbing on undersides, foliage drying out during hot, dry weather.
Spray foliage with a strong jet of water to dislodge mites. Apply insecticidal soap or horticultural oil to leaf undersides; repeat every 5–7 days as needed.