Can anyone tell me how or when to use the fertilizer? And what is the difference between them? I have bought some, but it does not let me use it on any of the available plants? Any help would truly be appreciated!

The fertilizer should be used on fully mature flowers. It won't work on immature flowers, or the vegetables. Certain flowers are more fragile than others, and the different fertilizers help keep them stable, but you should experiment to see which one works best on which flower (no sense in using a Tier 4 fertilizer on a Tier 2 flower!)

I should mention that all flowers will be vibrant while in inventory, but when they are planted, they might be brown, if they need water or fertilizer (if necessary).

Ahh! Thank you! That makes sense now.

A couple of observations on fertilizer:
-When your flowers turn brown, water them. IF after watering them they remain brown, they need fertilizer.

-When you go to the store to buy fertilizer, you will notice that the "type" will be highlighted. This seems to indicate the highest strength you currently need.

-When you have a flower that needs fertilizer, go ahead and "take" it (pick it up).
DO NOT FILL IN THE HOLE. Instead, go to your inventory and touch the flower.
(If you're still next to the hole, it will be replanted).
When you touch it in inventory, the name of the flower (I.e. Lemon Maranta) will be spelled out in different colored text indicating it's level of rarity.
*side note: this also applies to bugs and minerals*


I could be way off here, and if so hopefully some expert will step in and correct me. Still, this seems to fit my own personal observations and it's how I am doing it.

You're a little off on which plants need which fertilizer. I consider that spoiler information, BTW, but since you've posted it I'll correct it. I will leave the purpose of tier 4 fertilizer as an exercise for the reader.

I didn't know that about the highlights in the store. I'm excited to look at that today; I know one of my games has a brown seedling so it should be a hybrid.

Thanks for the corrections. Also, I didn't think about that possibly being spoilers, but maybe Xay will go back and hide it under a spoiler tag.

How about the fruit trees? Do they need fertilizer too or not, because I planted some trees and one of my apple trees is green while both of my pear trees are a bit brown looking...

Nope. No fertilizer for fruit trees. I don't know about the fir and pine and oak trees but I think not. I'll try it out and see.

I believe that the trees may be brownish because of the season? Just a hunch