What Makes a Plant Work in a Window Box?

Enhance your home’s charm with a DIY window box, accompanied by the perfect choice of plants. Before jumping into the best plants for your window box, you must understand what makes certain plants work better than others in containers.

You’ll find that most window box plants require ample sunlight and well-drained soil. You can fulfill this need by placing your window box on the sunniest side of your house and ensuring it has sufficient drainage holes. Essentially, you’ll care for your plants’ biological needs, and they’ll take care of your design wishes.

Window box plants are often divided into three categories based on the aesthetic element they achieve. 

  • Thrillers are the main attraction of your window display. They boast bold flowers and foliage and usher in the eyes of onlookers.
  • Fillers are often trailing plants that fill out the empty spaces in your window box. 
  • Spillers are vine-like plants that cascade, or “spill,” over the sides of your window box, creating depth and flow for the viewer.

    Read also: Quick and Easy Fall Window Box

    Here are our picks for the 20 best plants to create the most appealing window box on your block.

    Petunias

    Petunias are ornamental annuals that come in various colors, including red, pink, yellow, purple, and white. 

    These flowers are an excellent choice for window boxes because they can withstand the hottest months of summer while producing numerous bright blooms.

    Spreading petunias are a relatively short variety, growing to about 6 inches tall. However, this flower will spread 2 or more feet in the summer, making it a fabulous window box filler. Spreading varieties like wave petunias will produce so many flowers that passersby will hardly notice any foliage.

    Coleus

    Coleus is a popular accent plant for window boxes because of its eye-catching, multicolored leaves. Coleus come in shades of pink, red, orange, green, and yellow and range in height from 1 to 3 feet. 

    Coleus is mainly known for its stunning foliage. However, the plant also produces small flower heads that attract pollinators, bringing life to your window.

    Coleus plant cultivars have varying light needs, so you can select a variety that best suits the location of your window box. For example, the Alabama Sunset Coleus will thrive well in a full sun location, while the Chocolate Covered Cherry type does fine in partial shade.

    Begonias

    Plant begonias in your window box for heat-hardy beauty all summer long.

    Wax begonias are perhaps the best variety for window boxes. These annuals bud continuously throughout the summer season, bringing red, pink, and white shades to your window sill.

    Begonias look best when planted closely in containers, so place them 8 to 10 inches apart for a fuller appearance. You can also mix them with other annuals to diversify your display. 

    Use begonias in a well-drained window box with adequate sunlight exposure for the best results.

    Geraniums

    Select geraniums for your window box planter if you want a flower as diverse as it is beautiful. Geraniums come in many cultivars that vary in leaf shape, flower color, and stem height.

    Geraniums aren’t drought-tolerant, so you should water them regularly to prevent wilting and breakage. If any flowers die, deadhead them to prolong the plant’s growth.

    Geraniums grow best in well-drained, fertilized soil. Plant them in a deep window box with enough room for their roots to take hold. The Clemson University Cooperative Extension recommends mulching around the plants to keep them moist and cool in the summer heat.

    Impatiens

    Impatiens are one of the most popular window box plants because of their ability to thrive in containers. These distinct annuals typically do best in partial shade, but newer varieties can tolerate sunnier locations. 

    Regardless of light tolerance, most impatiens do well in warm summer weather. You can keep the plant hydrated by applying a layer of mulch to the window box. If the soil isn’t moist enough, your impatiens’ stems will soften and wilt.

    Impatiens grow in bright pink, orange, violet, lavender, red, and white shades that attract pollinators and bring months of color to your window.

    Pansies

    Pansies are the perfect cool-season annual for your window box. With over a dozen color varieties and a pleasant perfumey aroma, your bed of pansies is sure to attract the eyes and noses of all who pass by. 

    Plant your pansies as the cool weather of fall arrives. Water the flowers well after planting and continue watering through the winter if the box gets less than an inch of rain per week. Pansies will live into the spring as long as you maintain them with mulch and fertilizer. 

    Pansies typically die off when hot weather arrives, so consider replacing them with a bright summer annual for the following season.

    Verbena

    The verbena is a heat-tolerant ornamental that can thrive as an annual or a perennial. 

    The trailing variety of verbena is perfect for window boxes because of its low-spreading form and ability to blossom all summer. Trailing verbenas will grow up to a foot tall with a 5-foot spread when adequately maintained. 

    These pink, red, lavender and purple beauties grow best in full sun and well-drained soil. Eight to 10 hours of daily sunlight will produce the most flowers and prevent diseases. 

    Verbenas are drought-hardy flowers, but they can get thirsty in window boxes. Water weekly during dry spells to keep your verbenas healthy. 

    Read our article to learn how to grow Verbena and discover everything you need to know about Verbenas.

    Creeping Jenny

    Creeping Jenny – also known as moneywort – is a trailing plant that will add a perfect touch of greenery to your window box.

    Creeping Jenny is a popular spiller for hanging baskets and window planters because it proliferates rapidly, spilling over the sides of its container. The stems can grow more than a foot per month if properly maintained.

    The plant can have variegated green or chartreuse leaves, but the most common moneywort is the golden Aurea variety.

    Creeping Jenny is easy to care for and flourishes well in moist, well-drained soil. It prefers bright, sunny locations with full sun or partial shade.

    Sweet Potato Vine

    Sweet potato vine is another spiller plant to consider for your window box. 

    These fast-growing vines, often called ornamental sweet potatoes, sprout heart-shaped leaves of maroon, purple, chartreuse, and pink. This article from the MSU Extension Service suggests pairing sweet potato vine with coleus plants for a bright array of colors. 

    Ornamental sweet potatoes grow vigorously and can quickly crowd your window box. Simply prune back the unruly vines to clean up the container and promote healthy growth. 

    Otherwise, they’re easy to care for and require full sun, consistent watering, and well-drained, high-quality soil.

    Lobelia

    The lobelia is a flowering plant that blooms from early summer through mid-fall.

    Lobelias have a diverse range of flower and foliage colors, depending on the variety you select. The blossoms can be red, blue, purple, or white with solid or variegated leaves.

    Like many other window box plants, lobelias grow best in a sunny location with well-drained soil. Some lobelia varieties are trailing plants, so you can use them as a filler in your window container. 

    However, the blue and violet cultivars are so vivid that you might want them to be your window box’s main attraction.

    Marigolds

    Marigolds are easy-to-grow container plants that will bloom all summer long. 

    The two most common marigolds are the French and African species. The African marigold has large pompom blooms that can grow up to 4 inches across. The French marigold – which we recommend for window boxes – is a more compact variety with smaller flowers. 

    Marigolds come in shades of yellow, orange, or rusty red and have fragrant fern-like leaves.

    Keep your marigolds strong by ensuring they have an inch of water per week and total sun exposure. Deadhead wilted blossoms to encourage bright new growth as the growing season progresses.

    See our guide on how to care for marigolds.

    Salvia

    Salvia is a herbaceous perennial perfect for adding dimension to your window box. The plant is quite fragrant and will deter deer and rodents from snacking on your flower bed.

    These flowering herbs – which are part of the sage family – grow 1 to 5 feet tall, depending on the variety. Their height makes them an excellent option for the back of your window box display.

    Some salvia varieties grow well as annuals in cooler climates. The most popular ornamental salvia is bedding sage, which blooms in vivid scarlet-colored petals. This variety works well in window boxes with full sun or partial shade. 

    Other bedding salvia cultivars come in shades of purple, blue, pink, and white.

    Snapdragon

    The snapdragon is a cool-season annual that works well in partially shaded window box planters. The flower’s name comes from its tube-shaped blooms that resemble the mouths of tiny dragons. 

    Snapdragons vary in color with fragrant red, white, yellow, purple, and pink flowers.

    Depending on the cultivar you choose, snapdragons can grow up to 4 feet tall. The plant’s height makes it a good choice for the back of window containers but can also cause it to droop and fall over. 

    You can keep your snapdragons upright by staking their stems with supportive posts. Avoid this task by selecting a shorter snapdragon variety to fill your container.

    Vinca

    Vincas are low maintenance, heat-loving plants that make lovely window box flowers. 

    They commonly grow in varieties of white, lavender, red, and pink blooms with rich, green foliage. 

    Vincas thrive in containers that receive eight or more hours of sunlight per day. According to the University of Minnesota Extension, annual vincas are “native to semi-arid regions of Africa, which is why they do well in warmer and drier settings.” 

    You’ll know your vincas need more sun if they get leggy, sprouting a long stem that reaches up to the light. Otherwise, these ornamentals are easy to care for and require little water and fertilizer.

    Zinnias

    Zinnias are diverse annuals that thrive with little to no care. 

    Zinnias do well in warm, well-drained soil with total sun exposure. Once planted, they grow quickly and display vivid blooms throughout the summer season.

    Consider the Profusion Orange zinnia for your window box if you live in a humid climate. This deep orange cultivar is highly tolerant of mildew diseases that damage other zinnia varieties. Profusion zinnias are low-growing flowers with narrow leaves, making them an excellent filler for your window planter.

    You can explore other kinds of zinnias and discover “hundreds of cultivars and varieties” with dozens of color and shape features.

    Sweet Alyssum

    Sweet alyssum is a compact annual that grows in mounds. These cool-weather bloomers serve well as window box spillers, spreading over the container’s floor with clusters of delicate white flowers.

    Like other window box favorites, alyssum grows best in a container with ample sun exposure and porous soil. The flower blooms through the fall and winter, bringing beauty to your window during chilly months.

    Sweet alyssum flowers are most commonly white but also come in shades of purple and pink. You can select a species of yellow alyssum, or “Basket of Gold,” to brighten your winter landscape.

    No matter the color, alyssum blossoms exude a sweet, honey-like smell that will please onlookers and pollinators alike.

    Calibrachoa

    Calibrachoa is a South American trailing flower with sticky foliage and delicate blooms. The plant’s spreading habit makes it an excellent choice for hanging baskets, containers, and window boxes. 

    Common calibrachoa floral colors include white, bronze, yellow, pink, magenta, red, violet, and blue. These lovely annuals are called “million bells” because of their bell-shaped blossoms.

    Fill your window box with organic matter to produce the best calibrachoas. These flowers grow best in full sun with easy access to rich, nutritious soil. 

    Water calibrachoas daily to keep the potting soil moist but not oversaturated. Choose a window box with suitable drainage holes to improve water and air circulation. 

    Licorice Plant

    Licorice is a popular spiller plant because of its tendency to “creep up anything that gives it support.” Licorice plant can also act as a filler plant that occupies space under tall, leggy flowers. 

    The most notable feature of this charming shrub is its fuzzy, aromatic leaves, which range in color from silvery-white to yellowy-green. 

    Licorice plant comes from dry South African regions, so it does well in drought conditions. If you overwater your licorice plant’s soil, it can develop harmful diseases like root rot.

    Give this plant lots of sun and well-drained soil, and watch it carpet the floor of your window box.

    Nasturtium

    Nasturtiums are the perfect window box flowers because of their distinct foliage and eye-catching blooms. You can easily distinguish nasturtiums from neighboring flowers by their round, lily pad-like leaves.

    These warm-season annuals are relatively easy to maintain and can accent your window container as fillers or spillers. Trailing varieties will cascade over the edge of window displays in an array of orange and crimson blooms.

    Plant your nasturtiums in well-drained soil with full sun exposure for the best results. While their South American heritage lends them drought and heat tolerance, nasturtiums will bloom all summer long with regular watering. 

    Fuchsia

    Fuchsia is another popular choice for window boxes because of its bold color and unique shape. 

    Fuchsia will accent your window box from early summer through late fall, typically dying out after the first frost.

    We suggest selecting hardy fuchsia, or fuchsia magellanica, for your containers, boxes, and hanging baskets. Hardy fuchsia is an easygoing perennial that flourishes in the shade with moist, organic soil. 

    Fuchsia magellanica is generally a deep magenta color, but other varieties can be pink, red, and white.

    Read also: Stripped vs Black Oil sunflower seeds

    Additional Ways to Spruce Up Your Window Box

    Once you’ve filled your window box with brilliant blooms, you can add some other design elements for a personal touch.

    • Fairy lights – Create a magical display by hanging dainty outdoor lights on your window box or stringing the lights throughout the container’s greenery.
    • Bird boxes – Situate a birdhouse or bird feeder amongst your window box flowers to attract feathery friends. 
    • Ribbons – Adorn your window box with ribbons during the holiday season for a festive design. Consider decorating the box with other holiday items like wreaths and ornaments.
    • Pumpkins and gourds – Place pumpkins in and around your window box to prepare it for the fall season. You can even paint the decorative gourds to fit your garden’s aesthetic.

    Final Thoughts

    The key to successful container gardening is choosing plants that will grow and flourish right where they’re planted. With a window box full of easy-to-maintain plants, you’ll have a beautiful garden to enjoy without leaving your home.

    Remember to experiment with different visual aspects for your window sill display. Fill your container with plants of varying heights, spreads, colors, and shapes to create a remarkable design. 

    We have no doubt you’ll love decorating your sill with these 20 plants. Get creative and enjoy the endless possibilities of window box gardening!

    Editorial Contributors
    avatar for Elisabeth Beauchamp

    Elisabeth Beauchamp

    Senior Staff Writer

    Elisabeth Beauchamp is a content producer for Today’s Homeowner’s Lawn and Windows categories. She graduated from the University of North Carolina at Chapel Hill with degrees in Journalism and Linguistics. When Elisabeth isn’t writing about flowers, foliage, and fertilizer, she’s researching landscaping trends and current events in the agricultural space. Elisabeth aims to educate and equip readers with the tools they need to create a home they love.

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    Lora Novak

    Senior Editor

    Lora Novak meticulously proofreads and edits all commercial content for Today’s Homeowner to guarantee that it contains the most up-to-date information. Lora brings over 12 years of writing, editing, and digital marketing expertise. She’s worked on thousands of articles related to heating, air conditioning, ventilation, roofing, plumbing, lawn/garden, pest control, insurance, and other general homeownership topics.

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