For a beautiful container, start with the thriller

The ‘thriller, filler, spiller” adage for successful container design, which advocates for a focal point plant, plants to fill in around it and plants to spill over the edges, is not the only way to design a container planting, but it is a recipe for success that almost always delivers. And the thriller plant is the most important part of the equation, setting the tone for everything else that goes into a design.

When starting from scratch, it’s usually helpful to start with the thriller plant, and there’s no shortage of excellent options.

In the “most bang for the buck” category, consider annuals that quickly grow to great sizes for the same price as other annuals. Tall growing salvias such as the “Rocking” series from Proven Winners, or the Skyscraper series will grow to more than 3 feet tall, and as a bonus, invite every hummingbird in the area to swing by for a drink. Tall angelonia (summer snapdragon) varieties offer a similar look.

Continous-blooming sunflowers like Sunfinity and Suncredible offer cheery yellow flowers all season and top out at about 3 feet. 

Grasses make excellent options for centerpieces and can grow to great sizes throughout the season. In most cases, the more water they get, the more they grow (within reason of course). Purple fountain grass (Pennisetum) is a can’t-fail classic, but also consider red fountain grass such as Fireworks or the variegated Sky Rocket. Vertigo has broad, strappy foliage that can’t be beat for very large containers but can overwhelm average-size pots. Papyrus is thought of as a water plant, but it will grow well in a container and comes in a variety of sizes that range from 18 inches tall to 5 feet or more.

Many grasses can benefit from being contained within a planter, but planting them in a large nursery pot that is sunk into the soil of the decorative container is often the best bet. This keeps the grass from taking up all the room in the pot and ensures room for other plants in the combination to grow well.

Tropicals can bring bold foliage to the planter party. Cannas are easy to find and work well in containers but can be damaged by Japanese beetles. Elephant ears — Colocasia for sunnier areas and Alocasia for shadier spots — are impressive centerpieces as are angel’s trumpet (Brugmansia) and devil’s trumpet (Datura), although both are poisonous. Red abyssinian bananas (Ensete ventricosum) grow to incredible sizes in a single season in large pots.

Ti plant (Cordyline fructosa) is a stunning centerpiece for shade containers (you might find it being sold with the houseplants), but good old-fashioned, tall-growing coleus works well too. Ferns, of course, are a natural fit that provide amazing texture as well.

And, for a twist, consider a non-plant thriller, such as a beautiful obelisk on which you can train a vine such as mandevilla, purple hyacinth bean (Lablab purpureus) or morning glory (Ipomoea).

If you’re stuck on what to put in a planter, start with a thriller — there’s lots to choose from.