Floralis version: 6.2.0
Forge version: 43.1.1

Floralis flower seeds seem to be incompatible with other mods' farmland (tested with Farmer's Delight's Rich Soil Farmland, and Mystical Agriculture's Essence Farmlands). Flower seeds cannot be planted on it.

Thanks for reporting, I will take a look at it.

This will be fixed throughout the entire version range with the next update coming this week.