With a little effort, you can keep box displays going strong all year. Regularly check the soil, daily in hot weather, and water thoroughly when it feels dry a half inch down. Since nutrients wash out quickly from containers, fertilizer is a must. Good options include fish emulsion or liquid kelp, diluted to half strength and applied every two weeks.
Switch out cool-weather plants—pansies and cyclamen, say—for heat-lovers, like marigolds, as summer arrives. And as temperatures drop, try sneaking in edibles, like lettuce, for fall and a row of dwarf conifers for winter color.
Read on for more planting strategies to embellish a window-box planting, one that can last as long as you wish and will never stop pleasing.
Shown: A cheery combo of lantanas, impatiens, geraniums, petunias, and sweet alyssum spills over a deep box that spans three windows.