there is no card or spell to harvest. the instructions say that you can harvest repetatively until it gets to elder and then only once when elder is achieved. but i have bought all the spells from farley and none dsay to harvest, the closest one is only to plow
I haven't experienced this yet myself, still a couple hours to go, but I've been told that being mature isn't enough. Your "time to Harvest" lets you know when you will be able to harvest your plants. And putting things your plants like near them may help speed things up. :-)
Right. The pop-up tells you how much time is left UNTIL you can harvest. The pop-up will also tell you when you can harvest.
To actually harvest, you need to shut down the Gardening interface. Then, as you approach a harvestable plant, you'll get a "Press X to harvest" prompt.