What are some easy ways to tell when a product has been "greenwashed"?

I asked this question before, but I'm not happy with the answers so I'm reposting.

I'm thinking about when I shop for groceries, how can I be certain that what I buy is actually legitimately organic and green -- not just playing into the trend of late.

To quote Macmillan English Dictionary:

greenwash (also green-wash)

verb

to try to convince people that you are doing something which is good for the environment by being involved in small, environmentally-friendly initiatives, especially as a way of hiding your involvement in activities which are damaging to the environment

Source: http://www.macmillandictionary.com/New-Words/05011...