Flowering Bulbs: A Complete Guide to Spring and Summer Bulbs for Every Garden

The allium is actually a type of onion.

BULBS are nature's talent for packaging—containing all essentials to grow and flower. Some don't even need soil—witness paperwhite narcissus blooming in marble chips. But outdoors, bulbs really shine. Most are hardy and undemanding; some naturalize for years of color. Whether for borders, cutting gardens, containers, rock gardens, or naturalistic plantings, bulbs belong in every garden.

Generally, bulbs fall into two categories: spring-flowering (planted fall) and summer-flowering (planted spring). Lilies (Asiatics, Orientals, tigers) are exceptions—plant spring or fall for summer blooms.

Another crucial factor: hardy vs. tender. Hardy bulbs (daffodil, crocus, hyacinth, tulip, lily) survive winter in ground to bloom again. Tender bulbs (gladiolus, canna, dahlia) also flower yearly but in cold climates must be dug up ("lifted") in fall, stored indoors, replanted spring.

Naturalizing Hardy Bulbs

Naturalized plantings are popular for landscape bulbs. Instead of formal beds, scatter in irregular groupings across lawn/meadow/woodland edge. For natural effect, avoid straight lines or patterns.

Naturalizing in lawns works with smaller, daintier flowers: crocuses, puschkinia, squill (Scilla), grape-hyacinth (Muscari), snowdrops (Galanthus). These bloom early, foliage dies back quickly. If planting in lawn, don't mow until foliage yellows and dies—plant stores food for next year's bloom.

Most bulbs appreciate well-drained soil and sun. But early spring bulbs bloom and fade before deciduous shrubs/trees leaf out. Think of them like spring wildflowers. Open woodland or orchard suits long-stemmed showy ones like daffodils and early tulips, visible at a distance.

Some bulbs need dividing. Daffodils multiply into dense clumps, compromising flowers. Dig after flowering (while locatable), divide, replant immediately or store until fall.

For all bulbs, don't remove/mow spent foliage until withered naturally. Avoid planting long-standing bulbs in lawns where dying foliage creates mess. Try fields, meadows, or areas mowed once/twice yearly. Or plant at base of deciduous shrubs or in mixed beds where later-blooming plants hide spent foliage.

Prechilling and Forcing Bulbs

Nearly all hardy spring-flowering bulbs need "chilling" or cold dormancy before growth/bloom. For most North American gardeners, fall planting provides this. Just select bulbs hardy in your zone.

Gardeners in mild winter regions (Zones 9-10) must select carefully. Daffodils in December/January (coldest time), but tulips, crocuses, hyacinths may need special treatment. Select varieties rated for warm springs/summers.

Many tulips grow well as annuals in the South if prechilled. Good warm-climate bulbs: crocuses, hyacinths, lilies, muscari, colchicum (autumn crocus), alliums (ornamental onions).

Easiest prechilling: store in refrigerator at 40-45°F in breathable mesh bags (like garden center bags). After required weeks, remove and plant outdoors or in containers.

If refrigerator space allows, plant bulbs in containers and remove whole pot after chilling. Place forced containers in warm, sunny spot and wait for green leaves. After bloom, water pots, let foliage die naturally, then replant bulbs outdoors.

Most popular for winter forcing: paperwhite narcissus (no prechilling needed). But you can prechill other bulbs for indoor winter/early spring color.

Florists often sell forced single-type containers (dark purple or pink tulips)—smashing display. But be creative: force several kinds for mixed displays.

Unless large container or good design eye, experiment with only a couple types per pot. Plant bulbs of similar height with complementary form/color (pink alliums and white Dutch crocuses).

Forcing pots often lack drainage holes (paperwhites grown in stones, not soil). Can grow other bulbs this way, but probably can't replant outdoors unless grown in soil. For soil forcing, ensure drainage holes and catch dish.

Tulips

Although technically perennials, many gardeners find tulip bulbs short-lived, declining over 2-3 years with smaller flowers, eventually dying out. Unless climate/conditions ideal (hot dry summers, cold winters, well-drained soil), some varieties won't commit long-term.

But some types, with special care, flower repeatedly and increase in size/beauty—"perennial tulips." Many highly recommended varieties fall here. Note: Darwin hybrids with deep colors naturalize better than pastels.

For best perennial tulip conditions: top-dress with well-rotted cow manure or slow-release fertilizer (9-9-6 or lower) in fall. After spring bloom, deadhead spent blossoms, allow foliage to mature/wither naturally for next year's energy.

Lilies

Lilies are no harder than other hardy bulbs, with a few important differences.

Plant immediately upon receipt, fall or spring. Lacking papery tunic, they dry out quickly in storage.

Demand well-drained soil more than other bulbs. Plant at 6" depth, but till soil to 12"+, remove rocks, add leaf mold/peat moss for structure/drainage. Bone meal at planting hole bottom appreciated, but no other fertilizers needed then. Wait for green leaves, then sprinkle complete organic fertilizer and water in.

Mulch with compost, well-rotted manure, or wood chips/cocoa shells for moist, cool soil. Cover beds over winter with straw/evergreen boughs against freeze/thaw cycles.

During flowering, remove spent blooms but don't cut >1/3 of stem (reduces vigor/longevity). Difficult if cutting for arrangements—consider some in perennial beds, others in cutting garden.

Growing Tender Bulbs

Tender bulbs = summer-flowering group: dahlia, gladiolus, tuberous begonia, canna, calla lily (Zantedeschia).

Technically not "true bulbs"—don't contain tiny flower/stalk inside. Grow from corms (gladiolus), tubers (dahlia, caladium), rhizomes (canna). But just as dependable, grown similarly.

Exotic summer-blooming bulbs integrate into perennial gardens, but popular for arrangements—often planted in vegetable or cutting gardens. Plant ~same time as beans, after last spring frost. Around first fall frosts, dig up and store for winter.

Vary in hardiness—impossible to give general instructions; distinct preferences for light, soil structure, fertility.

Zone 8+ gardeners can overwinter cannas, callas, others. Most popular method: dig around first fall frosts, dry briefly, store in paper/mesh bags or shallow pan/box covered with dry peat moss. Ideal storage: dry, dark, cool (40-50°F).