Window box gardening

Window boxes are an ideal way to garden. You can experiment with different plant combinations on a manageable scale and at the same time add flowers and greenery to your surroundings. With a little bit of innovation you can add tremendously to your home landscape.

Window boxes should be as popular a passion as Christmas light displays. A balcony adorned with flowers brightens up an otherwise mundane looking apartment building. Clay pots filled with trailing geraniums are a splendid accessory to the front steps. It would be a sure sign that we have learned to appreciate the joys of horticulture if more of us took the time to plant window boxes and containers for the enjoyment of ourselves and others.

Planning an effective window box or container garden involves many of the same design considerations as when planning a garden bed. You must consider the microclimate that exists at the location such as amount of sunlight, rain and wind. Your garden centre can help you to select the suitable plants for your needs. The colour combinations can range from a single planting of ‘Purple Wave’ petunia to a riot of colour offered by a mixture of different annuals.

For a successful window box there are a few basic requirements which are easy to furnish. The soil should be a mixture of regular garden soil and a “soilless” mix comprised of peat and other organic material. The soilless component is important since these materials are lighter. They make containers easier to handle and window boxes are a lighter load on the structure on which they are attached. Be aware that a window box’s soil will dry out faster than the soil in the garden bed so will need to be watered more often.

Holes should be drilled in the bottom of the containers or boxes so that the water can drain out the bottom. It is important to consider where this extra water will go! Pebbles or broken pieces of clay pots should be placed in the bottom of the boxes and containers to ensure that the water can freely flow out of the pot and that the holes do not get plugged.

Containers can be made of any material that can withstand the weather. Terra cotta, wood and plastic are the three most common materials. Old tin watering cans, sinks, bathtubs or any similar type of vessel can be used as long as they are durable and able to drain.

Traditionally, trailing vines and colourful annuals combine to form most window boxes. The variety of annuals available to the gardener today make the assortment of designs almost limitless. Herbs, perennials and even shrubs can be used as long as protection from the winter elements are provided.

Window boxes can be changed throughout the year to reflect the changing seasons. The box can be used simply to hold flower pots which you may grow in other areas or purchase when you see something which suits your fancy. Pots of daffodils and crocus could be replaced by a mixture of trailing geranium, lobelia and marigolds after the spring bulbs have finished. Fall mums are readily available in many pot sizes and could be used to finish the season.

Window boxes should be jammed with as much plant material as possible. The goal is not to design a long term garden but to get as much out of a small space as possible. Fertilization is important with window boxes because there are a lot of plants growing in a relatively small space of soil. You may use a controlled release fertilizer which is mixed into the soil prior to planting, or use a water soluble 15-30-15 ‘Bloom Booster’ every 2-3 weeks.

This year, I am going to try a mixture of red verbena, blue lobelia, dwarf yellow marigold, coleus and perhaps an annual grass such as millet or foxtail.