Patch Plants Options Don't Appear

I recently downloaded the Garden Box and a few patch plants along with it, but I can't seem to get it to work. I can select the agent, click inject, and start dragging the green box that shows the area it'll grow - that all works just fine. But when I click it again to set the second corner of the box, the box disappears and the options that are supposed to show up never do, and nothing grows. (I have apples, pears, and chocolate roses and it did the same thing with all three of them.)