To make potpourri last longer, keep it covered as many hours a day as it is open. Many people close the jar or cover the dish at night, opening it each morning. Try to keep the blend out of the sun, which will cause it to fade and the scent to dissipate. If the fragrance does fade, simply treat it as you would a brand new mix - add orris root and oil and let it blend in a large jar for two weeks.

You can do the same thing to an old potpourri that you did not make yourself. If you can tell by looking at tit what its main fragrant ingredients are, add oils to match them. If you are not sure what its ingredients are, use rose or bay oil for a floral blend, jasmine or sandalwood for an oriental blend, and cinnamon or orange for a spice blend.