Swiss chard is a leafy green grown for its edible leaves and stalks. It is a biennial in the beet family, grown as an annual. Stalks come in white, yellow, pink, and red, and the plant tolerates both heat and light frost better than spinach, giving a long harvest window.
Chard is cut-and-come-again: harvest outer leaves and the center keeps producing for months. Seeds are clusters that produce multiple seedlings, so thin after germination. It bolts less readily than spinach but will eventually flower in its second year or under stress.
Cercospora Leaf Spot
Small round spots with tan or gray centers and reddish-purple borders on leaves. Spots merge in severe cases, causing leaves to brown and die back.
Remove infected leaves and avoid overhead watering. Space plants for airflow and rotate crops. Apply a copper-based fungicide if the infection spreads.
Downy mildew
Yellowing on top of leaves with grey-purple fuzz underneath. Spreads rapidly in humid conditions.
Remove affected leaves. Improve air circulation. Avoid overhead watering. Copper spray as preventive.
Spinach Leaf Miner
Pale, winding tunnels or blotchy translucent patches between the upper and lower leaf surfaces, caused by larvae feeding inside the leaf.
Remove and destroy mined leaves promptly. Cover plants with floating row cover to block egg-laying flies. Clear nearby weeds like lambsquarters and chickweed that host the pest.
Aphids
Clusters of small soft insects on new growth and flower buds.
Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.
Damping Off
Seedlings collapse at the soil line with thin, water-soaked stems; seeds may fail to emerge or rot before sprouting.
Sow in well-draining mix, avoid overwatering, and ensure good airflow. Remove affected seedlings and let the surface dry between waterings.