Window Box of Flowering Plants Creates High Impact Summer Color

Last Updated on July 3, 2019 by Kimberly Crawford

Grab the attention of passersby by stringing a couple of railing planters together and planting the potting soil with high impact flower colors. The foundation of this colorful summer garden is a zonal geranium, sweet alyssum and new million bells.

The seen-from-the-street combination begins with inspiration from a new plant that will be available in 2012, Superbells® Cherry Star. A zonal geranium, Pelargonium ‘Cola Purple,’ and a favorite sweet alyssum, Easter Bonnet in violet, were used to complete the container planting.

Unexpected foliage color is a good backdrop while a new flower will undoubtedly garner double takes. When assembling containers, gardeners may want to add more plants for heightened value; with foliage for variety, feathery flowers for soft edging or familiar colors for eyes to rest.

New Calibrachoa Cherry Star

Superbells® Cherry Star is a new Calibrachoa hybrid that will be out in spring 2012. This million bells variety grows well in full sun and tolerates summer heat. The bloom’s shining deep pink color is inlaid with a well-defined star, the lines streaming from the petite yellow-painted trumpet center. The miniature petunia-like flower form is a favorite of hummingbirds and butterflies.

The Superbells® Cherry Star plant eventually acts as a trailing plant that reaches 7” – 10” tall. Gardeners should leave 10” – 12” between plants when growing several side-by-sides in a landscape. This annual needs no deadheading.

Calibrachoa, often called million bells, is a frequently used annual for a combination in potted gardens. Only in hardiness zones 9 – 11, Calibrachoa is a perennial plant.

Zonal Geranium Cola Purple

Annual geranium plants are very popular in northern gardens because, although they reliably flower in hot summer locations, the plants like a cool bed to grow their roots. Pelargonium x hortorum ‘Cola Purple’ was chosen for this combination for its 10” height, iridescent coral color and the zonal marked leaves. Each leaf has a rounded form with scalloped margins; an inner portion of dark burgundy is set over green.

Annual geraniums, botanically called Pelargonium, have a flower shape often described as a dense umbel, tending towards 2” – 3” in diameter. Pelargonium ‘Cola Purple’ has flowers on stems, which rise high above the zonal leaves.

Geraniums are susceptible to a number of diseases triggered by humid environments; clearing out dead leaves and stems and deadheading dying flowers is sound plant care for geraniums. Annual geraniums are also favorites of Japanese beetles; whether in planting beds or containers, refrain from growing geraniums in the same location from year to year.

Sweet Alyssum Easter Bonnet Violet

Easter Bonnet Violet is a sweet alyssum chosen for the railing planter because of its fine-textured ball of color, a quality the plant has been known for many years to have. The fragrant flowers make a compact edger that will flourish in full sun, somewhat less in part sun.

Lobularia maritime ‘Easter Bonnet Violet’ grows 4” – 6” tall. Its light dainty appearance will soften a garden, placed at the rim of a pot or landscape’s edge. This sweet alyssum prefers cooler temperatures and tends to shut down mid-summer. Other sweet alyssum with similar habits and colors include Royal Carpet with a violet purple and Rose O’Day with lavender rose hues.

The recently new Lobularia ‘Snow Princess’ is a much more assertive sweet alyssum. In this planter combination, it is likely Snow Princess would overpower other annual flowers as one plant requires a wide space to spread.

Growing Flowers in a Railing Planter

Railing planters are pots preformed to rest over a thick railing of fencing that closes off a patio or deck. Predrilled planters from the manufacturer may have plug inserts, gardeners putting live plants inside the containers will want to remove these stoppers. Drainage holes at the base must be opened before filling the containers with soil to grow plants successfully.

The daily watering, required for plants withstanding the heat of summer sun, will wash nutrients from the soil over time. To maintain healthy plants the entire growing season, gardeners will want to add continuous-feed fertilizer pellets at the start and, at mid-summer, use a diluted half-strength liquid fertilizer, at two-week intervals.

Bold Colors in a Summer Planting for a Container Garden

Gardeners, who choose bold colors in their flowering plants, will garner attention to their container gardens. Among the newest blooms to add to summer plantings, Superbells® Cherry Star will be an annual that can be used as a filler and spiller in a pot.

Window box and hanging basket combinations come in numerous configurations. Geraniums, sweet alyssum and million bells are frequently used annual plants for this purpose or in landscaped beds.