In this promo you plant seeds and keep them watered to harvest gifts from them, and evetually, your plant that you can harvest a Divine from will be matured and you can harvest it.
Pass buyers hold the advantage here as you get fertilizer in HoPs and your divine plant, the Divinitis, will only make it by the ending date with a LOT of fertilizer. Most plants gain about 10% a day average, but this plant can only get 1% a day and 1% from fertilizer so you'll be spending well over 100 passes on it if you hope to get anything.
The way it works is you plant seeds in the garden plots, water them ever so many hours, and if you want to spend the passes fertilize them too. You can win a lot of free tack apples, turnips, BMIs ranging from 1 pass things like C. fortunes or WoYs, to expensive or priceless things like Nyx packs or Hestia's gifts or Hermes' Winged Staff.
Eventually you will get to unlock more plots and grow more at once and get a seed for the Divinitis plant, and you can grow the new Divine, Agate with it
A little about Agate fomr the horse's ? tab:
"Agate is a valuable horse.
The turnip button can change into a diamond button and give you the opportunity to win one diamond.
You can increase its skills using diamonds."
It doesn't say that it's a gemstone horse although it looks like one and awards diamonds and can be boosted skill wise with them, like all the gemstone divines, so that seems to be a gray area.
This is Agate:
As always, happy Howrseing,