Brown Spots on Indoor Pepper Plants: Watering & Calcium Fix

Brown spots on ‘Boonies’ peppers by a sunny window usually signal inconsistent watering causing calcium deficiency (blossom-end rot on leaves).

The Mechanism

• Frequent shallow watering → roots stay near surface → calcium (immobile nutrient) can’t reach new growth.
• Result: necrotic spots on leaves and fruit tips.

Corrected Watering Routine

1. Water deeply once per week until water exits drainage holes.
2. Allow top 1–2″ to dry between waterings.
3. Use room-temperature water; avoid softened water (high sodium).

Supplemental Calcium

• Foliar spray: 1 tsp calcium chloride or calcium nitrate per gallon, weekly.
• Soil drench: crushed eggshells in vinegar (extracts calcium), diluted 1:10.

Environment Check

• Pot size ≥ 3 gal for mature pepper.
• 6+ hrs direct sun or supplemental grow light.
• Good air circulation (small fan) to reduce fungal risk.

Consistent deep watering resolves 90% of leaf-spot cases within 2–3 weeks.