The store stocks more marigolds everyday, so it is more profitable to grow them and then sell them. Also, the coins that come out of them can't be collected unless you or stinky the snail does it, but stinky falls asleep really quickly unless you feed him chocolate (then he'll stay awake for one hour).
A Full minus 1 garden of glowing Marigolds gives me around 16-17k per chocolate. Any non-marigold plant should be sold as soon as it's fully grown. --- A widespread wolfpigeon rebellion will be immediately countered with the release of hundreds of thousands of flying sharks.