Rob D. Brodman
1. CALIBRACHOA HYBRIDS; Sunset climate zones 8, 9, 14-24 as a perennial; zones 2-7, 10-13 as an annual. Tougher than petunias, calibrachoa has smaller flowers that last longer and fall off cleanly after bloom. They're also abundant with ample water and fertilizer.
MiniFamous series. This year includes the first double calibrachoa.
Superbells series. Heat-resistant for hot-summer climates, these have large flowers in a wide range of colors. 'Tequila Sunrise' flowers are bright orange streaked with yellow.
How to use them. Use trailing calibrachoas in hanging baskets, mounding varieties as bedding plants (space 8 to 10 inches apart). For a showstopper in a large pot, pair Trailing Light Blue or cherry red Superbells with 'Palace Purple' heuchera or purple Ipomoea batatas 'Ace of Spades'.
2. NEW GUINEA IMPATIENS HYBRIDS; perennial in zones 24, H1, H2; annual elsewhere. Plants need sun to bloom well. Choose an area that gets morning sun and light afternoon shade (full sun all day at the coast). Give them ample water. Feed regularly, starting 3 weeks after planting.
Pure Beauty series. Comes in a range of solid colors, including pink, violet, orange, and white. Plants grow as 18- to 24-inch mounds, great in pots and garden beds.
Celebration series. Flowers are large ― 3 inches across. Use trailing kinds in hanging baskets.
How to use them. Pretty in beds with colorful foliage plants that thrive in part sun. Mass them in patio pots or pair them (Celebration 'Pink' is pretty in a chocolate brown pot with Iresine herbstii 'Blazin' Rose'). In a 12-inch hanging basket, plant five seedlings of a trailer such as Fanfare 'Orange'.
3. SALVIA SPLENDENS; perennial in zones 21-24, H2; annual elsewhere. You can give them full sun in mild-summer climates, but they'll have a much longer season of bloom in partial shade where summers are hot. They need moderate water and occasional feeding to stay strong.
Picante series. Grows 15 inches high, 10 to 12 inches wide, and produces huge flower spikes in the red, salmon, and wine color range. If you have space, try 'Van Houttei', whose 3-foot-tall, 4-foot-wide stature supports maroon flowers tinged with scarlet-orange.
How to use them. The mixture has more zing than blocks of single colors (though scarlet has plenty of impact by itself, especially if contrasted with the chartreuse leaves of 'Marguerite' sweet potato vine). Bed these out in the shade of a high-branched tree.
4. TWINSPUR (DIASCIA BARBERAE); perennial in zones 1-10, 14-24, H1; annual in colder zones. Full sun, or afternoon shade where summers are hot. Regular water. Feed at planting time, then repeat at summer's end. Shear back after each bloom cycle for repeat flowers.
'Denim' (part of the Sun Chimes series). New this year and already a favorite. Deep blue flowers atop 10-inch stems have a pink wash on the petals. Two spurs (thus the name) on the back contain oils that attract bees. Also look for the species, whose flowers are pink.
How to use them. A mat-forming plant, twinspur looks great massed in beds. But it also makes a pretty companion for roses in 22-inch containers; it thrives in the same growing conditions and its colors complement a wide range of roses, especially those with blooms in apricot shades.
5. ZINNIA ELEGANS; annual all zones. Plant in full sun in a spot that gets good air circulation. Feed regularly and snip off faded flowers to keep new ones coming. Among the easiest plants to grow from seed, zinnias need protection from snails and slugs.
'Zowie!' Intricately patterned, flame-colored flowers make this such a unique zinnia that its breeder decided not to turn it into a series. This true annual grows 2½ to 3 feet tall.
Magellan series. Try this for 12- to 14-inch-tall zinnias in red, pink, white, yellow, and orange.
How to use them. In our trials last year, one seed packet of 'Zowie!' filled a 4- by 8-foot bed with color until frost. Just give the plants plenty of room (we spaced ours 18 inches apart). Mass them in pots, or try a trio of plants in a container with a fringe of trailing blue scaevola.