Can't plant seeds. HELP!

[Tyberio]

I've seemingly tried everything but the game isn't allowing me to plant seeds or dried flowers in planter boxes. I've built the boxes and I see the icon allowing me to drop the seeds into the box but when I pull them from my inventory and hover over the icon, nothing happens. There also isn't the "insert" option when I right click on the seeds. Tried it with just about everything in the game. I also verified integrity of game files. Any other ideas? Thanks!

[Argelle]

Some seeds need a small planter, some other a big one.
Not exchangeable :)

[Jaunitta 🌸]

Flowers need to be dried.
Once built, place a valid seed into the plot.
To place a seed in to the planting box, open the backpack, pick up the seed by pressing and holding down the Left Mouse Button and drag the item on to the planting box or press the Right Mouse Button and select "insert" from the drop down menu.
Here is a list of plantable seeds
https://greenhell.fandom.com/wiki/Plant_Cultivation