What Kind of Annual Flowers Should I Plant in a Window Box?

Full Sun

• There are a number of annual plants that are ideal for growing in window boxes that will thrive in full sun. Petunias, especially the wave petunia, verbena, lantana, vinca and geraniums are ideal choices because they can handle hot, dry areas. Window boxes in full sun will need to be watered at least once a day, even if you select drought-tolerant plants. A good way to prevent the soil from drying out too quickly is to use water-absorbing crystals in your potting soil or use a potting soil designed for containers. An area that receives sunlight for at least six hours each day is referred to as being in full sun.

Intermittent Shade

• Intermittent shade occurs when a large object, such as a tree, filters the amount of sunlight the ground below receives. Coleus, fuchsia and caladium will thrive in intermittent shade. Coleus and caladium are grown primary for their foliage and are ideal for the back of the window box or, if you prefer, they can be grown alone. Fuchsia is a trailing plant, so plant it near the front of the window box so it can hang over the edge and soften the look. Fuchsia will stop blooming during the hottest part of the summer if the soil is not kept cool enough. Mulch and regular watering will go a long ways toward keeping the soil cool.

Light Shade

• Light shade occurs when an area receives full sun for five hours or less per day. Pansy, torenia, nasturtium, lobelia, bacopa, nemophila and tuberous begonia, as well as many annual plants that prefer full sun, will thrive in light shade. You will notice that full sun plants grown in light shade will not bloom as prolifically due to the decrease in light. The advantage of light shade is the soil in your containers will not dry out as quickly, although the soil in the window boxes still needs checked once a day to see if water is required.

Dense Shade

• Dense shade is the hardest type of shade to grow flowers in, especially annual flowers. The reason for this is because dense shade means there is very little, if any, light that reaches the area, which makes it hard for a lot of plants to thrive. For comparison purposes, think of what it is like when you walk deep into the woods. These are the same light conditions that annual plants grown in dense shade will receive. Impatiens and wax begonia are the two best annual flowers for growing in this type of shade.