Starf

Starf is a type of Berry that can be planted in the Farm. It can be obtained by having at least 1 empty plot while encountering a shiny Wandering Pokémon. To start encountering wandering Pokémon you need at least 1 ripe berry on your farm.

Possible Planting Formations
You can fill your farm in the following way to have the best chance to obtain Starf berries. Note that the setup omits a 24th Roseli, as that would allow Custap berries to mutate, which would occupy the empty plots. Purple squares indicate where mutations can occur.

Important Notes
If possible, it is highly recommended to obtain at least 8 Passho berries prior to obtaining the Starf Berry mutation. Without any Passho berries surrounding the Starf plot, harvesting a Starf plant (Even with a rich mulch applied) will only ever yield 1 Starf Berry. Furthermore, harvesting a single ripe Starf berry with the maximum yield modifier (surrounded by ripe Passho berries (8 spots) and with a rich mulch applied to the plot it is on) will still only yield 8 Starf berries. It is necessary to use a combination of Passho berries and Ripe Mulch to increase the total amount of Starf berries one has (excluding finding additional Starf berries randomly or using the Enigma berry).