ANNUALS ARE nature on overdrive. If a garden is all about seasonal change, the ebbing and flowing of flower and leaf, then annuals are a concentrated form of that rhythm: They bud, bloom and die in the space of a few months.

Which makes them relatively inexpensive, fun to play around with and gratifyingly fast-growing. Plant a few seeds, plunk some starts into a pot or the ground — and there's your summer garden. All mistakes and regrets are erased at first frost when annuals turn to compost; you get to start over next May.

Despite their brief life span, annuals should never be underestimated. From leafy coleus to the latest little petunia, they enliven decks, patios and gardens. And unlike more permanent plantings, annuals are at their best mid-to-late summer when we're actually outside enough to appreciate them.

• Annuals have been derogatorily called "color spots" as if they're nothing more than blobs of color. Ageratum 'Lemon Lime' boldly celebrates being an entire color scheme all in itself. Blue-purple flowers are shown off by vividly variegated lemon and lime-colored leaves. Planted in a mass, they look like both sun and sky have settled into the garden.

• It's hard to remember a time we didn't have dwarf-flowering petunias (a.k.a. superbells or calibrochoa) to trail out of hanging baskets and tall pots. But I'd guess that 10 years ago these useful flowers were no more than a light in some plant breeder's eye. New this year is 'Cherry Star,' an especially eye-popping version in hot pink centered with a yellow star. Superbells need sun, regular water and fertilizer to put on their summer-long show.

• I love zinnias for their retro looks, and because they're a long-lasting cut flower. They're also easier to integrate into mixed borders than most annuals because they have tall, sturdy stems and the look of a perennial. Zinnia elegans 'Candy Scabiosa Mix' is noteworthy for a harmonizing yet wide range of colors that include pink, gold, orange, cream and red.

• While zinnias may look old-school, Salpiglossis sinuata 'Black Trumpets' is an instant garden update. The flowers are fashionably dark burgundy touched with a gold center deep in their shapely throats. They look a bit like mini-lilies or perhaps black orchids . . . definitely shadowy and exotic. Yet the plant is bushy and free-flowering, and the flowers are beautiful in a vase.

• Ornamental sweet potato vines have come on strong as foliage annuals the past couple of years. Their dramatically shaped leaves look their best draping down the sides of pots, window boxes or hanging baskets. But be aware: These heat-loving vines will sulk if you don't plant them in as warm a spot as you can find. Fresh this year is Ipomoea batatas 'Sweet Caroline Raven' with deeply cut, pointed, dark-purple leaves that give off a glint of magenta.

• It's impossible to talk about new annuals without considering at least one coleus. The ideal foliage plant for shady locations and the darling of colorists, coleus are part of the everything-old-is-new-again annual crowd. The new 'Keystone Kopper' coleus is striking, with pink/orange foliage that casts a metallic gleam. Each leaf is meticulously veined with delicately scalloped margins for a superbly decorative effect.

'Keystone Kopper' is being marketed as heat-tolerant and deer-resistant. As with all these new annuals, time will tell on virtues beyond beauty. In the meantime, their good looks should be enough to win them a place in the garden for summer.

Valerie Easton is a Seattle freelance writer and author of "petal & twig." Check out her blog at www.valeaston.com.