There are a number of perennials listed above (yes, it would be helpful if that was indicated and if there was a link to each plant—we’re working on that). Some examples include lamb’s ear, astilbe, hosta, geraniums. It’s important to consider the specific needs of each plant: astilbe likes slightly acidic soil (around 6.0), coleus even more acidic (5.5 to 6.0), geraniums like it about 5.8 to 6.3, and lamb’s ear sweeter than all of these (6.0 to 6.5). To keep such plants thriving you could put them into the window box in plant pots and fill around them with sphagum moss or the like. The challenge of the plants in the window box, even in pots, if that they ae not protected from the harshest freezes; they are exposed on all sides, where as if they were in the ground, they would be —well—grounded. You could transplant them into the ground in fall and dig them up in spring. Or lift them from the window boxes (in pots, if you do that), and put them in a protected area (basement, garage). Do not abandon them; water them a bit every once in a while. Geraniums can be pruned to a few inches and brought indoors. Another way to keep your costs down is to start plants from seed, especially annuals. Hope this helps!
There are a number of perennials listed above (yes, it would be helpful if that was indicated and if there was a link to each plant—we’re working on that). Some examples include lamb’s ear, astilbe, hosta, geraniums. It’s important to consider the specific needs of each plant: astilbe likes slightly acidic soil (around 6.0), coleus even more acidic (5.5 to 6.0), geraniums like it about 5.8 to 6.3, and lamb’s ear sweeter than all of these (6.0 to 6.5). To keep such plants thriving you could put them into the window box in plant pots and fill around them with sphagum moss or the like. The challenge of the plants in the window box, even in pots, if that they ae not protected from the harshest freezes; they are exposed on all sides, where as if they were in the ground, they would be —well—grounded. You could transplant them into the ground in fall and dig them up in spring. Or lift them from the window boxes (in pots, if you do that), and put them in a protected area (basement, garage). Do not abandon them; water them a bit every once in a while. Geraniums can be pruned to a few inches and brought indoors. Another way to keep your costs down is to start plants from seed, especially annuals. Hope this helps!