I've tried so far (not of it will grow anything):
- 2 Plain sweet + Very Sour
- 2 Very Sweet + Very Sour
And something will grow on following recipe:
- Plain sweet + 2 Very sour
Invalid combo so far
Plain Spicy + Very Sweet = Qualot Berry.
Plain Sweet + Very Sour = Grepa Berry
Another source (Im not the owner):
https://docs.google.com/spreadsheets/d/1QUjC6xY-UTDvAKRTWM_foVzEboVutteTxpblM0Bwfds/edit#gid=0