Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Beware of expiration!

Be aware that nowhere on the website does it say that this item must be opened and used within 30 days. However, that information was printed on the box so when I received it I called the company to determine if that 30 days is simply a "recommended to be used by" date (I wanted to give it as a Christmas gift). They informed me that while there could possibly be a 5-7 day "grace" period, the 30-day limit is pretty firm. The company will not refund or exchange this item. I'm sure this is a good product but be sure you are planning to open and start it growing immediately.