Brown Spots on Potato Leaves: Water, Fertilizer, or Manure Issues?

Brown spots often indicate overwatering or excess nitrogen from fresh manure. Horse manure applied in September may not have fully composted by February planting.

Corrective Actions

• Water deeply only when top 2 inches of soil are dry.
• Add elemental sulfur to lower pH and mitigate nitrogen burn.
• Mulch with straw to stabilize moisture.
• For new planting, use only aged (6+ month) manure or compost.

Potatoes are resilient; later growth should normalize as manure finishes breaking down.