And season after season, we see visitors pulling out smartphones and cameras to photograph and document those gorgeous combinations.

In this month's Smart Gardener, we bring you a few of the most visually exciting summer combinations. These seven terrific trios can translate easily to your own yard, garden, deck, or patio.

(Click the image of each triplet for a larger view.)

A "Wow" Trio

The colors and textures of Redbor kale, dahlias, and Cherie hibiscus are the focal points of a bed that also includes a profusion of lantana, impatiens, petunias, and ornamental peppers.

Even insiders at the Garden look to the entrance bed at the Visitor Center for great combo ideas. For summer, horticulturist Dan Dion planned a stellar grouping of plants, including this gorgeous yellow/coral/burgundy trio:

• Kale 'Redbor' (Brassica oleracea 'Redbor')
• Bishop of Llandaff dahlia (Dahlia 'Bishop of Llandaff')
• Cherie hibiscus (Hibiscus rosa-sinensis 'Cherie')

Dan's full roster for the bed also includes:

• Diva dahlias (Dahlia 'Diva')
• LITTLE LUCKY^â„¢ Red lantana (Lantana camara 'Balluced')
• FANFARE^â„¢ Orange trailing impatiens (Impatiens 'Balfaforg')
• Storm Blue petunia (Petunia x hybrida 'Storm Blue')
• Garda Fireworks pepper (Capsicum annuum var. annuum 'Garda Fireworks')

A Trio That Sings

Not yet displaying its distinctive catkin-like inflorescences, the serrated edges of the burnet leaf complement the coleus leaf; perilla mimics coleus's coloring as the transition plant in the trio. Tiny, peachy pimpernel flowers complete the look.

Near the Heritage Garden, horticulturist Tom Soulsby assembled a strong trio for the Asia bed that he based on the interesting foliage of burnet:

• Burnet (Sanguisorba tenuifolia purpurea)
• Trusty Rusty coleus (Solenostemon scutellarioides 'Trusty Rusty')
• MAGILLA^â„¢ Purple perilla (Perilla frutescens 'Balmagpurp')

A note on burnet: later in the season, it will set its distinctive, catkin-like purple flowers, and show its brilliant orange and gold fall color. While waiting for the burnet to bloom, Tom accents with Wildcat Mandarin pimpernel (Anagallis monellii 'Wildcat Mandarin'), an unusual peachy-orange pimpernel.

Container #1

Mauerelli Abyssinian banana (Musa ensete 'Maurelli')

Million Kisses® tuberous begonia (Begonia 'Yadev')

Foxtail fern (Asparagus densiflorus 'Mysersii')

Container #2

Alumroot 'Black Beauty' (Heuchera 'Black Beauty')

Coleus 'Giant Exhibition Chivalry' (Solenostemon scutellarioides 'Giant Exhibition Chivalry')

Joseph's Coat 'Sommelier Pinot Gris' (Alternanthera 'Sommelier Pinot Gris')

Container #3

Bauer's dracaena (Cordyline 'Baueri')

Million Kisses^® tuberous begonia (Begonia 'Yadev')

Silver Falls silver nickel vine (Dichondra argentea 'Silver Falls')

1 + 1 + 1

In the Circle Garden, horticulturist Dale Whiting simplified the idea of a trio by planting one big, healthy, interesting plant in a single pot, then clustering three pots together.

This easy-to-execute solution for a dull garden or patio corner has big extra benefits: glory flower sends up fantastic spikes in late summer, curry plant packs a powerfully spicy fragrance, and the variegated Swedish ivy trails luxuriously down to the ground as summer goes on.

• Blue glory bush (Tibouchina grandiflora)
• Curry plant (Helichrysum italicum)
• Variegated Swedish ivy (Plectranthus coleoides 'Aurea-marginatus')

A Tiny Trio

Even a single trough can make a big statement. In the troughs at the English Walled Garden, horticulturist Heather Sherwood designed "mini-landscapes" by combining small plants with powerful textures:

• String of pearls (Senecio rowleyanus)—those "pearls" are actually the succulent's modified leaves!
• BLACK SCALLOP^â„¢ bugleweed (Ajuga reptans 'Binblasca')
• Swedish mosaic ivy, or spurflower (Plectranthus oertendahlii)

Horticulturist's tip: String of pearls grows quickly and trails beautifully—and is easy to share with fellow gardeners!

Dwarf Conifer Garden

At the top of the stairs to the Dwarf Conifer Garden, horticulturist Ayse Pogue recommended a permanent trio—two dwarf conifers and one perennial—that could be the solution for lightening up a dark corner of your yard with bright, golden color.

• Repens Gold creeping Norway spruce (Picea abies 'Repens Gold')
• Krakus arborvitae (Thuja occidentalis 'Krakus')
• Thriller lady's mantle (Alchemilla mollis 'Thriller')

Three in One

And for those who have the smallest spot of sun on the smallest balcony of the smallest apartment, distill the idea of a trio all the way down to a single plant. Rosa 'Savalife' is better known as RAINBOW'S END^â„¢ for a good reason: it combines three of the colors of the rainbow in one gorgeous flower.

Wish you had room for pink roses, coral roses, and yellow roses? The clustered flowers of RAINBOW'S END^â„¢ give you all three in one.