SOYOUWANNA GROW A WINDOW GARDEN?

3. GET THE RIGHT PLANTER

Ultimately, you will want your planter to be more or less obscured by foliage, which means that the planter's appearance doesn't matter too much. A window box makes an ideal planter for a window garden-their rectangular shape is easier to secure than rounded pots, and they create the appearance of uninterrupted growth (even when individually potted plants are resting inside them).

Size

• You want your garden to fit the length of your window (that is, the vertical depth). Remember, your window garden acts like drapery to enhance your window, so don't buy a window box that dwarfs your home by comparison. Besides, if your window box is too big, it becomes unwieldy and difficult to install.
  
  
• Horizontal depth (that's "front to back" for the linguistically challenged) will determine how many rows of plants you can fit in your window garden. Typically, you don't want anything deeper than three rows.
  
  
• The remaining dimension to consider is the vertical height (how deep shall your garden grow?). If you only plan on growing your window garden from the spring through the fall, a depth of seven or eight inches is sufficient. If you wish to grow plants year round, however, you need a window box twelve to fifteen inches deep. Extra depth allows you to add insulating material to keep plant roots and bulbs from freezing.

Materials

• If you want a window box that is astoundingly elegant and heavier than Mama Cass, look for limestone, terra-cotta or cast-iron window boxes. These materials are great for window garden in formal architecture such as brownstone homes, museums and small castles, although they are not at all practical for beginners.
  
  
• For the frugal window gardener, a plastic window box will prove far more pragmatic, if somewhat less regal. They are the most affordable, are truly lightweight and hold moisture well. And while plastic may seem terribly tacky (or trendy in a kitschy way), bear in mind that your foliage will probably trail low enough eventually to cover most of the planter. However, plastic planters do become brittle and crack with age, so be prepared to replace them every couple of years.
  
  
• When buying a wooden window box, choose durable, rot-resistant wood such as California redwood, cedar, pine and marine plywood. Avoid spruces and firs.
  
  
• For a truly natural look, there are window boxes made from matted straw or similar organic materials set into an iron frame. They are surprisingly attractive on brick rowhouses, where they soften the severity and angularity of the architecture.
  
  
• Avoid tin window boxes. You don't want to bump into it and have to get a tetanus shot, do you?
  
  
• Window boxes are available in most hardware and gardening stores as well as chains like Wal-Mart, K-Mart and Home Depot. Of course, the truly industrious gardener can build a window box from scratch. Even Martha Stewart will be jealous.

Drainage

• Whether buying (or building) a window box, drainage holes at the bottom are a must. Although keeping the soil constantly moist is important, constantly saturated soil will cause your plant to rot. Waterlogged soil is prone to develop fungal and bacterial growth making it unfit for future plantings, not to mention slimy and stinky.