foetida is usually self pollinating; edulis may or may not be self compatible OR "self" pollinating; caerulea may or may not be self compatible OR self pollinating. When in doubt- pollinate by hand and keep careful notes. Transfer pollen as soon as flowers open for best results or when the anthers drop down to the plane of the petals. Edulis on caerulea might work. Foetids will not pollinate the other two in my experience