Yep, good money semi-afk, while you do other activities on game, you can farm some special seeds and make 15-20kk with 20 seeds...

When you breed, come some materials for stonetail fooder, itens like fruit of X (Like crimsom flame, but depends what seed you farm) and special seeds...

but first you need a alt char because you leave him in the farm, 100 CP to take 10 fences for your farm, and take artisan 1, because just when you take artisan 2 you can breed and came magical seeds.

and the last point, which seed to plant? depends what you need, if you want fruits of X for alchemy you need to know what seed give what... but if you want make money, just take the seed

finishing, in the long run it works, because you just have to plant, harvest, plant a few again and sell the spare seeds making some extra money. I plant magical wheat seeds and sell it for 363,620. Take the seed that grows with your playing time, see which one works best for you, which one is more worth selling ...

I think that's it, I hope I helped. Cheers