By Andrew Bunting, PHS VP of Horticulture 

As the weather warms, this is the perfect time to start thinking about planter ideas that provide instant impact in the garden. There are a myriad of reliable and unexpected annuals and tropicals that bring bold foliage, abundant flowers, and, in many cases, exceptional pollinator activity to the garden. 

Containers can be positioned throughout the garden in many ways. Groupings or vignettes of containers can effectively fill a corner of a patio. They can be used to flank entrances or provide symmetry on either side of a bench. A large single container can also become a stunning focal point. Whether you garden in full sun, deep shade, or a compact urban space, there are countless container gardening ideas that can transform patios, balconies, porches, and small gardens throughout the summer season. 

How to Design a Beautiful Summer Planter 

A noted container designer once coined the terms “thriller, filler, and spiller” when it came to designing a container. The “thriller” is the main focal point of the container. The “filler” plants soften and surround the thriller, while the “spiller” plants cascade gracefully over the sides. 

This simple approach remains one of the easiest ways to create balanced and visually dynamic easy summer planters. 

Bold Tropical “Thrillers” for Containers 

One of the fastest ways to elevate a container from ordinary to extraordinary is by incorporating plants with dramatic foliage and strong architectural form. Tropical plants excel in this role because they grow quickly, thrive in summer heat, and create an immediate sense of abundance. Their oversized leaves and upright habit naturally draw the eye, making them ideal "thrillers" in the center or back of a container design. Even a single tropical plant in a large pot can create a striking focal point on a patio, deck, or garden entrance. 

Elephant Ears 

Elephant ears, particularly species and cultivars of Colocasia, are excellent for their luxuriant tropical foliage and are ideal “thrillers” in large containers. 

One of the finest chartreuse selections is Colocasia Royal Hawaiian® ‘Maui Gold’, with leaves reaching up to four feet long. It performs beautifully in full sun and can also brighten a shady corner. 

Dark-leaved cultivars create a completely different effect. ‘Illustris’ remains a classic, with green leaves dramatically veined in black. Colocasia ‘Black Magic’ (syn. ‘Jet Black Wonder’) forms bold clumps of oversized black foliage reaching four to six feet tall and is hardy to USDA Zone 7B and above. ‘Black Beauty’ offers black leaves with contrasting green veins, while ‘Coal Miner’ combines impressive size with dark foliage. Colocasia esculenta Royal Hawaiian® ‘Diamond Head’ makes an unforgettable statement with glossy black leaves that shimmer in the light. 

Canna Lilies 

Cannas are another indispensable “thriller” for outdoor planters. Their upright foliage creates strong architectural lines, while the flowers add vivid color throughout summer. Like all tropical foliage plants, cannas benefit from a slow-release fertilizer in spring followed by regular feeding with a nitrogen-rich liquid fertilizer during the growing season. 

Canna Tropicanna® (syn. ‘Phaison’) remains one of the most spectacular selections available. The foliage is boldly striped with burgundy, pink, orange, and green, while vivid orange flowers rise above the leaves. Plants can reach seven feet tall under ideal conditions. 

A more compact version is ‘B. Marley’, reaching about 3.5 feet tall. Another longtime favorite is Canna ‘Bengal Tiger’ (syn. ‘Pretoria’), which combines orange flowers with green and yellow striped foliage. It performs equally well in sun or partial shade and can even be grown as an aquatic in shallow water gardens. 

‘Red Stripe’ is a newer introduction with striped foliage and striking pink-red flowers. Canna ‘Orange Punch’ and ‘Lemon Punch’ are slightly smaller selections reaching about four feet tall with brilliant orange and lemon-yellow blooms, respectively. 

The compact Cannova® series is especially useful for medium-sized containers. Cannova® Rose, Cannova® Yellow, and Cannova® Bronze Orange all provide exceptional flower power, while Bronze Orange pairs deep bronze-black foliage with vivid orange flowers. 

Two older cultivars still deserve recognition today: ‘Australia’, with shiny black-red foliage and scarlet flowers, and ‘Wyoming’, which combines burgundy-green foliage with glowing orange blooms.

The Best “Filler” Plants for Summer Containers 

While thrillers provide structure, filler plants are what make containers feel lush and complete. These plants help knit a design together by adding texture, color, and volume around the focal plant. Many of the best fillers bloom continuously throughout summer or offer colorful foliage that remains attractive even when flowers are not at their peak. They also help soften the strong lines of tropical plants and create a more natural, layered appearance. 

Begonias 

Begonias have experienced an extraordinary renaissance in recent years and are among the finest summer annuals for containers, especially in shade. 

Begonia ‘Canary Wings’ has quickly become a standout selection nationwide. Cherry red flowers bloom continuously from late spring until frost, while the foliage emerges bright yellow before aging to chartreuse. It performs exceptionally well in part shade and works beautifully in hanging baskets, window boxes, or mixed containers. 

The Jurassic™ and Jurassic Jr™ Rex begonias are equally valuable for their dramatic foliage. ‘Watermelon’ features striking silver, purple, and green variegation. ‘Cherry Spike’ combines dark burgundy margins with silver-veined centers, while ‘Silver Point’ offers luminous pewter foliage. 

Coleus 

Modern Coleus (syn. Solenostemon) now ranges from low-growing edging selections to towering focal plants exceeding four feet tall. 

‘Inferno’ reaches about 28 inches with rich rusty-orange foliage and performs well in both sun and partial shade. It combines beautifully with chartreuse foliage plants such as Canna ‘Pretoria’, Colocasia ‘Maui Gold’, or Xanthosoma ‘Lime Zinger’. 

ColorBlaze® Sedona Sunset offers similar coloration and vigor. ‘Redhead’ produces robust burgundy-red foliage that pairs beautifully with pink-flowering annuals such as Gomphrena ‘Fireworks’ and Salvia greggii ‘Mirage Pink’. 

‘Henna’ provides exceptional texture with frilled foliage that blends golden-yellow, pink, and red tones together. For smaller spaces or edging, ‘Limewire’ and ‘Inky Fingers’ offer finely cut foliage with dramatic dark centers and green margins. 

Zinnias 

Zinnia, Zinnia elegans is an old-fashioned annual which has seen a resurgence thanks to new breeding work focused on flower form, color, and disease resistance. They remain some of the best annual flowers for planters and also make great cut flowers. 

The ‘Benary Giant Series’ produces large dahlia-like blooms up to six inches across in shades of scarlet, orange, salmon, bright pink, golden yellow, and carmine. 

The ‘Oklahoma Series’ offers smaller but more abundant semi-double flowers on sturdy stems, while the ‘Zinderella Series’ features blooms resembling coneflowers or scabiosa in unusual antique shades of peach, lilac, and soft pastels. 

Marigolds 

Marigolds have also seen a resurgence in popularity. The Antigua Series produces large globe-shaped flowers, while the Crackerjack mix provides bold yellow, orange, and golden blooms throughout the season.

Best Heat-Tolerant “Spiller” Plants for Summer Planters 

No container feels finished without plants that gracefully spill over the edge. Spillers soften hard container lines, add movement, and create a fuller, more mature appearance. Because they are often exposed to reflected heat and drying conditions near the rim of a pot, the best spiller plants are vigorous growers that flower continuously and tolerate summer stress with minimal maintenance. 

Petunias 

Petunias remain among the most versatile and widely used spiller plants. Both the Supertunia® and Wave® series are prized for their vigorous spreading habit and nearly nonstop bloom in virtually every color imaginable. 

Verbenas 

Like petunias, verbenas will bloom all summer long and with a little deadheading, will be covered in flowers. The Superbena® series is especially notable for heat tolerance and flower production. ‘Homestead Purple’, despite being introduced decades ago, remains one of the finest deep purple selections available. 

Pollinator-Friendly Annual Flowers for Summer 

Many gardeners today are interested in incorporating pollinator-friendly container plants into patios and outdoor living spaces. Fortunately, many annuals combine ornamental beauty with ecological value. 

The following annuals are especially attractive to bees, butterflies, and hummingbirds: 

• Petunia (single-flowered types)  
• Verbena  
• Angelonia  
• Salvia  
• Cuphea  
• Zinnia  
• Pentas  
• Gomphrena  

Easy Summer Planter Ideas and Container Combinations 

One of the easiest ways to create a beautiful container is to follow the classic "thriller, filler, spiller" design approach. The thriller provides height and drama, the filler adds color and fullness, and the spiller softens the edges by cascading over the sides of the container. Below are some combinations to get you started!

Thriller, Filler, Spiller Container Recipes 

• Canna ‘Pretoria’ + Solentostemon ‘Inferno’ + Verbena ‘Homestead Purple’ 
• Colocasia ‘Illustris’ + Begonia ‘Canary Wings’ + Solenostemon ‘Inky Fingers’ 
• Canna ‘Orange Punch’ + Solenostemon ‘Henna’ + Verbena Superbena® Violet Ice 

Simple Two-Plant Container Combinations 

Not every container needs a thriller, filler, and spiller. For smaller pots or a more minimalist look, pairing just two complementary plants can be equally effective. 

If you are looking for quick and reliable planter ideas, the following combinations are especially effective: 

• Bold Tropical Container: Colocasia + Canna  
• Pollinator Planter: Salvia + Pentas  
• Shady Foliage Combination: Begonia + Coleus  
• Floral Profusion Container: Zinnia + Marigold  

Container Gardening Maintenance Tips 

Even the best-designed containers require routine care to look their best throughout the growing season. 

• Grooming and Deadheading: Regular grooming and deadheading will keep containers fresh, tidy, and blooming continuously. 
• Water is Essential: Containers dry out quickly during periods of heat and drought. Consistent watering is critical, especially for large tropical plants and flowering annuals. 
• Fertilizing is Critical: Use an organic-based fertilizer to encourage lush foliage and abundant flowering throughout the season. 

Why Container Gardening Continues to Grow in Popularity 

Container gardening is an approach that can be utilized by almost everyone. For city dwellers, it may be the only practical way to garden. For others, containers simply accent and embellish an existing landscape. 

Containers also provide an excellent opportunity for experimentation, allowing gardeners to trial new tropicals, annuals, and foliage plants each year while creating dynamic seasonal displays filled with color, texture, and pollinator activity.