Best Summer Bulbs: Calla, Dahlia, Gladiolus, Asiatic & Oriental Lilies

Summer bulbs bring explosive color and form to borders and containers. Tall types (5–6 ft.) like Oriental lilies and dahlias make dramatic backdrops; shorter ones (2–4 ft.) accent perennial plantings. After years of trialing, here are our top picks for flower power and unique coloring.

Calla (Zantedeschia hybrids)

Dwarf hybrids outshine classic white callas with vivid colors—glowing orange, soft pink, lavender—and some have "windowed" leaves. Plants 1–2 ft. tall. Excellent in massed containers (16–18 in.).

Favorites: 'Mango' (orange with red flames), 'Flame' (yellow-orange aging to red).
Zones: 5, 6, 8, 9, 12–24; H1, H2.
Exposure: Full sun on coast; light/afternoon shade inland.
Plant: Rhizomes rounded side down, bumpy eyes up.
Water: Regular once growth hits 6–12 in.; keep moist, not soggy.
Sources: Pacific Callas (800-533-8573) for 'Mango'; Van Bourgondien (800-622-9997) for 'Flame'.

Dahlias

Festive, diverse, and bouquet-perfect. Heights 15 in. to 5+ ft. Flower forms include waterlily, anemone, cactus, daisy. Best cut stems are long, strong, with 3–4 in. upward-facing blooms.

Favorite: Waterlily Dahlia Mix (oranges, pinks, reds, yellows, bicolors; 4–6 in. up-facing blooms; 3–4 ft.).
Zones: 1–24.
Exposure: Full sun.
Plant: 1-ft. deep holes, 1½ ft. wide (large), 9–12 in. wide (small).
Water/Fertilizer: Regular water from 6–12 in. growth; low-nitrogen fertilizer (10-20-20) at planting.
Sources: Dutch Gardens (800-818-3861) for mix; Swan Island Dahlias (800-410-6540) for tubers.

Gladiolus (Grandiflora hybrids)

Modern hybrids offer exciting blends: 'Jester' (yellow/orange throat), 'Mon Amour' (pink/yellow), 'Columbine' (salmon shades). Small/mini types (3–4 ft.) need no staking.

Favorite: 'Far West' (deep garnet splashed yellow; 3–4 ft.).
Zones: 4–9, 12–24; H1; annual elsewhere.
Exposure/Soil: Full sun; rich, fast-draining (add 3 in. compost).
Plant: Pointed side up.
Water/Fertilizer: Regular water from 6–12 in.; granular fertilizer 6 in. from base at 5-leaf stage.
Source: Dutch Gardens (800-818-3861) for corms including 'Columbine', 'Far West', 'Jester', 'Mon Amour'.

Asiatic Lilies

Easiest, most reliable lilies. No fragrance, but dazzling colors (orange, red, yellow, rust, pink, cream, white). Up-facing, horizontal, or drooping blooms. Stems 1½–4½ ft. Short 'patio lilies' (e.g., 'Pink Pixie', 'Marlene') excel in pots.

Favorite: Strawberries & Cream Mix (pinks, rose, cream, magenta; some spotted; 30–40 in.).
Zones: 1–9, 14–24; A1–A3.
Exposure: Full sun coast; light/afternoon shade inland. Mulch for cool roots.
Plant/Water: Pointed up; regular water all year.
Sources: White Flower Farm (800-503-9624), B&D Lilies (360-765-4341), Dutch Gardens (800-818-3861).

Oriental Lilies

Most exotic and fragrant. Mid-July–Sept. bloom. 5–10 in. flowers in pink, red, white, often spotted/banded. Clusters on strong stems. Most tall (2–5+ ft.); dwarfs like 'Miss France' (15–18 in.) shine in pots.

Favorite: Perfumed Garden Oriental Lily Mix (cream, crimson, pink, white; very fragrant; 3–5 ft.).
Zones: 1–9, 14–24.
Exposure/Plant/Water: Same as Asiatic.
Sources: White Flower Farm (mix); Van Bourgondien (800-622-9997) for 'Miss France', 'Garden Party'; B&D Lilies, Dutch Gardens.