by Ken Lain, the mountain gardener

Tall potted plants can turn ordinary container gardens into works of art. They add height, variety, and a little drama to mixed containers. But grouping plants in containers takes a finesse. The general formula is “thrillers, spillers, and fillers.” In other words, combine a tall (thrilling) focal point plant with something that spills over the side of the container to soften the lines. Finish with shorter filler plants between. Virtually any plant can succeed in a pot. Choose a large pot for the plant’s root ball as it grows. Also, ensure the container is heavy enough to anchor the plant in windy locations.

Here are Top 10 tall potted plants to grow in a container garden.

Agave is a large succulent type plant perfect as a focal point. There are many agave species, ranging in size and appearance. Several commonly grown varieties reach a few feet in height and width. Agave thrives in a relatively shallow pot with a drainage hole in the bottom. It prefers gritty soil, such as a cactus mix.

Alberta Spruce, Picea glauca, is a gorgeous conical evergreen with dense, bright needles. It is the number one seller for accent plants flanking door posts and beams. The Christmas tree format is natural for twinkle lights through the holidays.

Big Bluestem, Andropogon gerardii, is a lovely ornamental grass that adapts well in containers. This big plant crowds out others, so use a large pot when mixing in other flowers. Growing to 4′ feet tall by 2′ feet wide, they look fantastic in containers. Shade results in poor growth, so place the container where it will get at least 6+ hours of sun daily.

Boxwood, Buxus sempervirens, can be grown formally or funky. You can trim it to be anything you want. If you would like to exercise your creative flair, try a boxwood topiary. When left to grow, it reaches heights of about 5′ feet.

Canna Lily, with their large, showy flowers, adds instant tropical flair to container gardens. Summer flowers bloom multiple times, growing hip high. Cannas need lots of water and prefer “wet feet,” so keep the container moist.

Gilt Edge Silverberry, Elaeagnus ebbingei, offers a splendid combination of bright yellow margins on brighter green foliage, providing exquisite year-round interest. This 5′ foot plant is a bright specimen in partial shade gardens that need excitement. Suitable against darker backgrounds and a welcome color late in the year when flowering plants are done. A great way to interrupt long runs of dull foliage. 

Karl Foerster Grass, Calamagrostis acutiflora, is a cool-season grass, meaning it’s an early riser in the spring and blooms early in the season. After flowering, it remains upright and tall, not floppy or weepy like many other grasses. It is perfect for the center of a container, growing from 3 to 5 feet. It prefers damp soil and can even tolerate poor drainage.

Moscheutos Hibiscus look tropical.. This multi-stemmed perennial shrub is quickly grown in containers. Plant directly into Watters Potting Soil for the perfect drainage, and avoid deep containers to prevent the plant from expending too much energy on root development. Rose of Sharon Hibiscus is a much taller shrub variety with equally stunning hibiscus flowers.

Plum Passion Heavenly Bamboo, Nandina, is bred for increased color. A bright contrast in foliage-intensive landscapes. Skinny, graceful, and tall, it is perfect for narrow openings. Indispensable for courtyards, entry gardens, and high-profile architecture. A dramatic addition on a porch, patio, and balcony when planted in Glazed Ceramic Containers. Elegant when planted near water gardens and fountains.

Yuccas are about as hardy as they get and pretty enough to be the focal point of any container garden. Even the smaller varieties grow to roughly 3′ feet in height and width, so select a good-sized container. Many designers prune back the flower stalks and focus on the spiky foliage. Like Agave, they prefer gritty soil, such as cactus mix.

Free Garden Classes are offered @ Watters Garden Center

We go deep into growing better. Check out this Summer’s class selection offered every Saturday @ 9:30 am.

September  9 – Climbers & Covers in the Landscape

September 16 – Easy to Grow Mountain Plants

September 23 –Privacy Screens and the Secret Garden

September 30- Fall Containers that Bloom Like Crazy

Until next week, I’ll be helping gardeners grow healthy plants here at Watters Garden Center.

Ken Lain can be found throughout the week at Watters Garden Center, 1815 Iron Springs Rd in Prescott, or contacted through his website at WattersGardenCenter.com or Top10Plants.com.