Hanging Planters Draw the Eye

Yellow draws the eye, and purple keeps it there. Superbells Lavender calibrachoa and Bidens ferulifolia pair well in a hanging basket where they both need full sun and will deadhead themselves. Let the soil get almost completely dry before watering, as these drought-tolerant annuals don't like constantly wet soil. But during the hottest summer days, you may need to water daily.

Dynamic Duos

Lilies and clematis can be best friends because they like similar growing environments and bloom at about the same time. Both produce more flowers in full sun, but like their roots cool, moist, and shaded. Plant them together in a bed with rich soil where they'll get midday sun, but have protection from the late afternoon heat.

Bonus: Oriental lilies produce a sweet fragrance.

Golden and Sunny

Keep a garden looking sunny all season with golden barberry (Berberis thunbergii) such as 'Aurea' or Sunjoy Gold Beret. The barberry's thorns make an effective barrier for critters, and deer don't like to munch on the golden leaves. It coordinates beautifully with the red-violet 'Carnaby' clematis climbing on the rugged arbor and the white-and-purple 'Art Deco' iris.

Nature's Palette

A rustic path runs through beds of yellow mullein (Verbascum), blue catmint (Nepeta), and purple and pink lupines that look like Mother Nature planted them. To keep mullein blooming, remove the spent flowers before they form seeds. These spiky perennials are deer resistant, making them perfect for a country-style garden. Repeat the plantings to maintain the purple and yellow theme in a long bed.

Subtle Shades of Purple and Yellow

A color combination isn't always obvious. Saturated hues vie for attention in a composition of purple alliums, burgundy iris, purple lupine, gold arborvitae, and yellow yarrow. When planning a purple and yellow gold combination, remember that both colors run the gamut of shades from bold to pale and warm to cool. Any combination will blend but often looks best when you stick with similar blooms, such as all saturated, warm colors.

Layers Add Interest

If you have a tall plant, add dimension with something low-growing. Here, the bright blooms of low-growing perennial Sedum kamtschaticum and annual verbena make a splendid purple and yellow carpet at the feet of tall purple and yellow irises and spiky annual yellow butter and eggs (Linaria vulgaris). If you don't want butter and eggs to reseed, keep it deadheaded.

Texture Counts

When planning your flowerbeds, mix it up a little. Start with tall, spiky foxgloves (shown in pink and light purple) and spires of deep purple delphiniums. Add contrast with rounded shapes, such as yellow roses and nasturtiums. This grouping can easily be changed yearly since the nasturtiums are annuals, the foxgloves are biennials, and delphiniums are short-lived perennials.

Pink for Prettiness

Looking for the perfect partner to go with purple and yellow flowers? Pink always works. Pale yellow daylilies and pastel pink roses give a cool welcome in the foreground. At the same time, warm tones of purple coneflowers, red-purple liatris, purple catmint, and golden black-eyed Susans anchor the back. All prefer a full-sun location.

Accent Colors Add Interest

Some flowers carry color combinations within their structure, such as the Lemon Symphony African daisy, featuring yellow petals ringing a purple center. Play up the purple with a matching nemesia such as 'Bluebird." Nemesias and African daisies are cool-weather bloomers that don't like summer heat. So when temperatures drop in autumn, just trim them back and wait for flowers to reappear.

Thrillers, Fillers, and Spillers

You can't go wrong with the classic formula for container plants: thrillers (spiky, tall), fillers (midsize, rounded), and spillers (trailing). The blue pot adds depth to this combo because the color is close to purple on the color wheel. The thriller here is angelonia, the filler is a yellow dahlia, and the spiller is a deep purple petunia (look for trailing varieties.)

Roses and Clematis: Kindred Spirits

Roses and clematis are natural garden partners. Airy clematis vines can climb upward on a support or simply clamber horizontally among perennials. Select 'Polish Spirit' or Jackman clematis for a deep, rich purple variety. Roses, such as the award-winning golden English rose 'Graham Thomas,' can provide support—just make sure the rose bush isn't so smothered by the vines that it can't get enough sunlight to its leaves.

Paired to Perfection

Look to calibrachoa and Marguerite daisies for feathery foliage and long-lasting bodacious blooms. Place red-purple calibrachoa anywhere you want nonstop color. The yellow Marguerite daisy performs best in cooler weather, although new varieties, such as 'Butterfly', are more heat-tolerant. Both do well in the ground but excel in containers.

Spiffy Spring Performers

Count on these spring bloomers to put on a purple and yellow show, then quietly go away. Grape hyacinths and buttercup anemones combine well. From the many types of grape hyacinths, try Muscari latifolium, with florets of light purple on top and dark purple on the bottom. Plant both with other woodland perennials that will grow to cover the bare spots left when these go dormant.

An Easy Summer Combo

Some plants behave like well-trained dogs: Just unleash and watch them romp. The high-impact yellow of a black-eye Susan contrasts with the brilliant burgundy of a dark-leafed sedum. Both adore full sun and take almost no care, peaking in mid to late summer. Sedums are hardy perennials. While some varieties of black-eyed Susans only last one or two years, they readily reseed.

Sweet Fragrance

Adding heliotrope to any combination offers an enticing sweet fragrance; some say it smells like vanilla, while others call it cherry pie. Choose from purple, blue, or white blooms to contrast with yellow Asiatic lilies. For a fully fragrant duo, plant a yellow Oriental lily. The lilies are hardy, but heliotropes only last one season in northern climates. Both prefer a full sun location.

One Tough Trio

Want some rugged plants that will go ahead and make your day? Yellow yarrow, purple catmint, and deep-violet 'May Night' salvia stand up to almost anything nature dishes out. Once established, these three summer-blooming perennials are heat- and drought-tolerant. They prefer well-drained soil.