Experts and BHG readers answer.
Planting in front of windows
Choose plants that are adapted to full sun and dry conditions. Next the the house, plants are often get less moisture than those out in the open because of shielding by roof overhangs and walls. The exception is if plants are growing next to a downspout.
Good choices for drought-tolerant, sun-loving plants include: sedum, purple coneflower (Echinacea), red valerian (Centranthus), coreopsis, daylily (Hemerocallis), Russian sage (Perovskia), and catmint (Nepeta).