Bring water to a boil on the stove, then immediately remove from heat. Add hibiscus & rose petals, then steep for 5 minutes. Carefully strain out the solids. Add sugar, then return the pot to the burner. Bring to a simmer, then simmer for 1 minute. Remove from heat & allow simple to cool completely.
Once cool, strain through a fine strainer. Store your syrup in a clean, airtight vessel in the refrigerator for up to 1 month!