For GS campaign 10, you must find 5 hyper fertilizers along with the flower seeds. Instead of getting one hyper fertilizer from each of the npc's that carries it, you can get all 5 hyper fertilizers from one person. Go to the space port on second miltia, and talk to Rosa (the old lady by the save point). Talk to her over and over, and she will keep on giving you hyper fertilizer until you have enough.