You don't get the 6th from Ivy's Hut. You DONT COLLECT FROM THE LILIES AS YOU PLACE THEM. Wait until you place the 5th crafted lily, collect from them all......as soon as you get a Static Sap from any of the lilies, a goal involving Ivy gives you the 6th lily. If for some reason this flashes too fast, the lily may be in storage, check there.