diff --git a/web/src/features/moreCast2/util.ts b/web/src/features/moreCast2/util.ts
index 71ec26c2a..026c20a8d 100644
--- a/web/src/features/moreCast2/util.ts
+++ b/web/src/features/moreCast2/util.ts
@@ -149,8 +149,8 @@ export const fillGrassCuring = (rows: MoreCast2Row[]): MoreCast2Row[] => {
 
   for (const row of rows) {
     const stationInfo = stationGrassMap.get(row.stationCode)
-
-    if (stationInfo && row.grassCuringForecast) {
+    // fill the grass curing forecasted value, as long as it doesn't already have a value
+    if (stationInfo && row.grassCuringForecast && isNaN(row.grassCuringForecast.value)) {
       row.grassCuringForecast.value = stationInfo.grassCuring
     }
   }