diff --git a/frontend/src/pages/Properties/PropertyDetail.js b/frontend/src/pages/Properties/PropertyDetail.js
index 1bcbf15..a2224ec 100644
--- a/frontend/src/pages/Properties/PropertyDetail.js
+++ b/frontend/src/pages/Properties/PropertyDetail.js
@@ -661,13 +661,13 @@ const PropertyDetail = () => {
 
       const response = await propertiesAPI.createSection(id, sectionData);
       const savedSection = response.data.data.section;
-      
-      // Convert backend format to frontend format
+      // Convert backend format to frontend format; parse polygonData if string
+      const poly = typeof savedSection.polygonData === 'string' ? JSON.parse(savedSection.polygonData) : savedSection.polygonData;
       const newSection = {
         id: savedSection.id,
         name: savedSection.name,
-        coordinates: savedSection.polygonData.coordinates[0],
-        color: savedSection.polygonData.color,
+        coordinates: poly?.coordinates?.[0] || [],
+        color: poly?.color || currentColor,
         area: savedSection.area,
         grassType: savedSection.grassType || '',
         grassTypes: savedSection.grassTypes || []