As explained in the introductory post on shade grown coffee, there is no set definition of the term “shade grown.” Coffee may be labeled shade grown even if it is grown under minimal overstory that does little to preserve biodiversity.
The Smithsonian Migratory Bird Center has made the most well-known effort to establish criteria for shade grown coffee. In order to carry their trademarked “Bird Friendly” label, coffee must be grown under a minimum shade cover of 40%, and the overstory should include at least ten different species of shade trees, with no more than 70% of the trees being Inga species. Pruning of the overstory and the removal of epiphytes is discouraged, and buffer zones are encouraged. These are the most stringent environmental criteria. Bird-Friendly certification is primarily focused on growers in Central and South America, but expanding to Africa. A description of Smithsonian’s Bird Friendly criteria is here.
The Rainforest Alliance has a certification program (using standards of the Sustainable Agriculture Network) which they apply not only to coffee, but to other crops as well. For coffee, it deals with an array of ecosystem issues such as water conservation, and as well as use of chemicals, community relations, and fair treatment of workers. Certification is awarded based on a score for meeting a minimum number of an array of criteria. More information on Rainforest Alliance standards can be found here.
Unlike Smithsonian’s Bird-Friendly standards, RA has no required criteria for shade management. Therefore it is important to note that Rainforest Alliance-certified coffee may NOT be shade grown. The requirements for shade that are one of the optional criteria under ecosystem conservation can be seen in comparison with Smithsonian’s criteria here. There are seven other criteria relating to ecosystem conservation in the RA standards.
There are pros and cons to the certification process, including the cost to the farmers and roasters (particularly expensive in the case of SMBC), and problems with applying one-size-fits-all biodiversity criteria to different regions. Coffee farmers, particularly small producers, are ultimately in the business of growing coffee to support their families. They are not in the biodiversity preservation business. If we want them to do so, we have to respect that and be willing to make it profitable for them.
Some roasters offer shade coffee that is not certified, but evaluated in various ways. Some say they use independent auditors, or visit the farms themselves.I don’t know how many, if any, of these evaluators have experience in actually assessing biodiversity, from a scientific viewpoint. For more on this topic, please see Who evaluates non-certified coffee?