Previously, flower farm set up worked great. Bottom up: dispenser with bonemeal facing upward into soil platform. Place chosen flower on top of block and turn on clock to fire bonemeal, while using pistons to move platform and break flowers. Now it will only dispense bonemeal if soil has no flower or grass on it. Yet I can bonemeal flowers manually and spread them.

https://youtu.be/tuXgtad26YQ