You worked for hours helping Mom plant pachysandra way back when, but that doesn’t help you now, as you try to nurture a briefly blooming geranium display in an outdoor window box. It’s time to throw in the towel — literally. A standard window box (like the one shown here from North Country Cedar, $43, www.northcountrycedar.com), installed inside, just below the sill, proves fertile ground for storing a colorful array of hand towels and washcloths. Stick to one shade or mix it up and you’ll have your own version of a window garden. Even Mom may reap the benefits.