Our Recommendation - Cold Wash / Air Dry / Hot Iron
Your dress will last for years if you take care of it properly.  
To ensure wear for years, we "HIGHLY" recommend handwashing your dress separately by itself and air drying it like our grandmothers used to do.
If you prefer to machine wash your garment, you can wash it in cold water, and hang dry.
For a fresh and new look, use a hot iron to flatten any wrinkles.  
Clean and store your dress in a protective dust bag during dormant months.