All of the summer bulbs listed below come in a range of colors and sizes. You'll want to tuck clumps of them between perennials in beds and borders. Tall Oriental lilies and dahlias that reach 5 to 6 ft. make good backdrops for borders; shorter kinds (2 to 4 ft.) are good accents among small-flowered perennials or in containers. We've grown many kinds of summer bulbs over the years. In this chart, we highlight our hands-down favorites for unique coloring and sheer flower power.

CALLA. Zantedeschia hybrids.

Elegant as they are, white callas pale beside the newer, more vivid dwarf calla hybrids. Plants range from 1 to 2 ft. tall, depending on kind. Some have leaves with tiny clear "windows" that make them look spotted. Their flowers come in hotter shades such as glowing orange as well as softer pink and lavender. In the garden, colored callas make excellent border plants, and they thrive when massed in large (16- to 18-in.-diameter) containers.

OUR FAVORITES: 'Mango' (shown here) bears brilliant orange flowers with red flames and red-orange throats. We grew ours in a black lava pot for startling contrast. Plant grows 2 ft. tall. 'Flame', another favorite, looks similar (yellow-orange blooms resembling candle flames darken to red as they age).

GROWING TIPS: Sunset Western Garden Book Climate Zones: 5, 6, 8, 9, 12-24; H1, H2.

Exposure: Full sun on the coast or in overcast areas, light shade or afternoon shade elsewhere.

Planting: Plant rhizomes rounded side down and "bumpy eyes" side up.

Water: Start regular watering when growth is 6 to 12 in. tall; keep soil moist but not soggy all season.

SOURCES: Calla rhizomes are available in nurseries through March. Or buy plants in gallon cans in late spring. A mail-order source for 'Mango' calla rhizomes is Pacific Callas (800/533-8573). For 'Flame' calla rhizomes, try Van Bourgondien (or 800/622-9997).

DAHLIAS

Festive, easy, and available in many shapes and sizes, dahlias are summer's perfect flower. Depending on variety, plants grow from 15 in. tall to 5 ft. or more. Flowers come in deep, rich colors with eye-catching frills, splashes, or stripes. Some resemble water lilies; others are shaped like anemones, cactus flowers, or daisies. The best ones for bouquets have long, strong stems and flowers not much bigger than 3 or 4 in. across that angle slightly upward, not sideways.

OUR FAVORITES: Waterlily Dahlia Mix includes flowers in oranges, pinks (pale salmon is shown here), reds, yellows, and bicolors. Blooms are 4 to 6 in. across and face upward, making them ideal for bouquets or for floating in a water-filled glass bowl. Plants grow 3 to 4 ft. tall.

GROWING TIPS: Zones: 1-24.

Exposure: Full sun.

Planting: Dig 1-ft.-deep planting holes that are 11/2 ft. wide for larger dahlias (more than 4 ft. tall), 9 to 12 in. wide for smaller types.

Water: Start regular watering when growth is 6 to 12 in. tall; keep soil moist but not soggy all season.

Fertilizer: Mix low-nitrogen fertilizer (such as 10-20-20) into the soil at planting time.

SOURCES: Dahlias grow from tuberous roots, sold at nurseries this month. Potted plants are sold later in spring. Waterlily Dahlia Mix, pictured, is from Dutch Gardens (800/818-3861). For a wide selection of tuberous dahlia roots, try Swan Island Dahlias (800/410-6540).

GLADIOLUS. Grandiflora hybrids.

Garden gladiolus, which produce flower spikes that reach 3 to 6 ft. tall, bear flowers (up to 30 per spike) that are widely flaring. Newer hybrids "are not your grandmother's glads," says Sunset's test garden coordinator, Bud Stuckey. In addition to common flower colors such as apricot, green, lavender, orange, purple, red, rose, salmon, and yellow, they now come in exciting new blends such as bright yellow with orange throats ('Jester'), Easter egg pink and yellow ('Mon Amour'), and shades of salmon all on one spike ('Columbine'). Small and miniature types grow 3 to 4 ft. tall, stand upright without staking, and bear up to 18 flowers per spike, each 2 1/2 to 3 in. across.

OUR FAVORITES: 'Far West' gladiolus (shown here) bears flowers of deep garnet red splashed with yellow. All blooms open at once. Plants grow 3 to 4 ft. tall.

GROWING TIPS: Zones: 4-9, 12-24; H1; annual elsewhere.

Exposure: Full sun.

Soil: Rich, fast- draining. Dig in 3 in. of compost.

Planting: Pointed side up, root side down.

Water: Start regular watering when growth is 6 to 12 in. tall; keep soil moist but not soggy all season.

Fertilizer: Apply a complete granular fertilizer 6 in. from plant base when the first five leaves have developed.

SOURCES: Gladiolus corms are sold in nurseries this month. A mail-order source is Dutch Gardens (800/818-3861), whose selection includes 'Columbine', 'Far West', 'Jester', and 'Mon Amour'.

ASIATIC LILIES

Asiatic lilies are the easiest and most reliable lilies to grow in the average garden. What their flowers lack in fragrance they more than make up for in their range of dazzling colors ― from bright orange, red, and yellow to rust, pink, salmon, cream, and snowy white. Some have upward-facing blooms, others have horizontal or drooping flowers. Stems are strong, erect, and short (1 1/2 ft.) to moderate (4 1/2 ft.). Shorter kinds, often sold as patio lilies, are superb in containers. These include 'Pink Pixie' (bright pink with a yellow throat) and 'Marlene' (pastel pink).

OUR FAVORITES: Strawberries & Cream Mix, a refreshing blend of colors from pinks, rose, and cream (shown here) to magenta, some with spots, on plants 30 to 40 in. tall. Great for cutting.

GROWING TIPS: Zones: 1-9, 14-24; A1-A3.

Exposure: Full sun on the coast or in overcast areas, light shade or afternoon shade elsewhere. Mulch to keep roots cool.

Planting: Pointed side up, root side down.

Water: Regular water all year (the bulbs keep growing even after tops die back).

SOURCES: Asiatic lily bulbs are sold at nurseries in early spring. Mail-order sources are White Flower Farm (800/503-9624), whose selection includes Strawberries & Cream Mix; also try B&D Lilies (360/765-4341) and Dutch Gardens (800/818-3861).

ORIENTAL LILIES

Perhaps the most exotic and most fragrant of all lily hybrids, Oriental lilies bloom mid-July through early September. Long-lasting 5- to 10-in. flowers come in pink, red, or white and are sometimes spotted with yellow and banded with red. They grow in clusters atop strong stems. Most are tall (2 to 5 ft. or more), including 'Casablanca' (white) and 'Salmon Jewels' (peachy salmon with butter yellow centers and a sprinkling of crimson spots). A few ― such as 'Miss France' (soft rose with a white edge) and 'Garden Party' (white with golden yellow stripes) ― are dwarf varieties (15 to 18 in. tall); they're striking in pots, where they need a rich, fast-draining soil mix.

OUR FAVORITES: The Perfumed Garden Oriental Lily Mix includes flowers in shades of cream, crimson, pink (shown above), and white, all very fragrant, atop 3- to 5-ft. stems.

GROWING TIPS: Zones: 1-9, 14-24.

Exposure: Full sun on the coast or in overcast areas, light shade or afternoon shade elsewhere. Mulch to keep roots cool.

Planting: Pointed side up, root side down.

Water: Regular water all year (the bulbs keep growing even after tops die back).

SOURCES: Oriental lily bulbs are sold at nurseries in early spring. Mail-order sources are White Flower Farm (800/503-9624), whose selection includes Perfumed Garden Oriental Lily Mix; and Van Bourgondien (or 800/622-9997), which sells 'Miss France' and 'Garden Party'. Also try B&D Lilies (360/765-4341) and