When you shop for bulbs, you’ll see some labeled as “good for naturalizing.” This means that they can be counted on to come up year after year, and spread informally throughout your garden. The following spring- and summer-flowering bulbs are reliably perennial in habit. Plant bulbs in autumn.

(Average blooming periods in parentheses.)

Alliums

Require sun. They can also manage on the sunny edges of woods.
Allium aflatunense – Ornamental garlic (summer)
Allium giganteum – Giant onion (summer)
Allium karataviense – Turkestan onion (summer)
Allium moly – Lily leek or golden garlic (summer)
Allium neapolitanum – Naples onion, daffodil garlic, flowering onion (summer).
Allium oreophilum – Ornamental garlic (early summer)
Allium sphaerocephalon – Drumsticks, ballhead onion, round-headed garlic (summer). The best allium for naturalizing.

Anemones

Need sun and are beautiful in borders.
Anemone blanda ‘Blue Shades’ – Greek anemone, windflower (spring)
Anemone blanda Mixed – Windflower mixed (spring)
Anemone blanda ‘Pink Star’ – Windflower (spring)
Anemone blanda ‘White Splendour’ – Windflower (spring)

Crocuses

Come in a wide range of colors and will spread quickly.
Crocus ancyrensis – Golden bunch crocus (late winter/early spring)
Crocus ‘Blue Bird’ – Botanical crocus (early spring)
Crocus ‘Blue Pearl’ – Botanical crocus (early spring)
Crocus Botanical Mixed – Species crocus (early spring)
Crocus ‘E. P. Bowles’ – Botanical crocus (early spring)
Crocus ‘Cream Beauty’ – Botanical crocus (early spring)
Crocus ‘Jeanne d’Arc’ – Dutch crocus (spring/early summer)
Crocus ‘Pickwick’ – Dutch crocus (spring/early summer)
Crocus purpureus grandiflorus – Dutch crocus (spring/early summer)
Crocus ‘Remembrance’ – Dutch crocus (spring/early summer)
Crocus ‘Ruby Giant’ – Botanical crocus (late winter/early spring)
Crocus ‘Whitewell Purple’ – Botanical crocus (late winter/ early spring)
Crocus Yellow – Dutch crocus (spring)

Irises

Don’t naturalize in a competitive area.
Iris danfordiae – Dwarf iris (late winter)
Iris reticulata ‘Harmony’ – Dwarf iris (early spring)
Iris latifolia – English iris, can cover whole yard (early summer)

Muscari

Tolerate late snowfalls and work well with crocuses.
Muscari armeniacum – Blue spike, grape hyacinth (spring)
Muscari botryoides ‘Album’ – Grape hyacinth (spring)

Daffodils

Bring sunny colors to the garden before the taller tulips are in bloom.
Narcissus ‘Actaea’ – Small-cupped daffodil (late spring)
Narcissus ‘Barrett Browning’ – Small-cupped daffodil (midspring)
Narcissus ‘Birma’ – Small-cupped daffodil (midspring)
Narcissus ‘Carlton’ – Large-cupped daffodil (midspring)
Narcissus ‘February Gold’ – Botanical daffodil (early spring)
Narcissus ‘Flower Record’ – Large-cupped daffodil (midspring)
Narcissus ‘Fortune’ – Large-cupped daffodil (midspring)
Narcissus ‘Hawera’ – Botanical daffodil (late spring)
Narcissus ‘Ice Follies’ – Large-cupped daffodil (midspring)
Narcissus ‘Jack Snipe’ – Botanical daffodil (early to midspring)
Narcissus ‘Minnow’ – Botanical daffodil (early spring)
Narcissus ‘Mount Hood’ – Trumpet daffodil (midspring)
Narcissus ‘Peeping Tom’ – Botanical daffodil (early spring)
Narcissus ‘Salome’ – Large-cupped daffodil (midspring)
Narcissus ‘Suzy’ – Botanical daffodil (midspring)
Narcissus ‘Tete a Tete’ – Botanical daffodil (early spring)

Tulips

Hard to naturalize. You must be cultivar-specific in choosing those you plant, as only certain ones will work. The following are recommended for a naturalized setting.

Tulipa ‘Candela’ – Botanical tulip (early spring)
Tulipa ‘Orange Emperor’– Botanical tulip (midspring)
Tulipa ‘Don Quichotte’– Triumph tulip (midspring)
Tulipa ‘Kees Nelis’– Triumph tulip (midspring)
Tulipa ‘Praestans Fusilier’– Botanical tulip (early spring)
Tulipa ‘Princeps’– Botanical tulip (early spring)
Tulipa ‘Purissima’– Botanical tulip (early spring)
Tulipa ‘Red Emperor’– Botanical tulip (early spring)
Tulipa ‘Red Riding Hood’– Botanical tulip (midspring)
Tulipa ‘Toronto’– Botanical tulip (early spring)

These showy, lilyflowering tulips will also spread:
Tulipa ‘Aladdin’– (late spring)
Tulipa ‘Ballade’– (late spring)
Tulipa ‘Maytime’– (late spring)
Tulipa ‘Red Shine’– (late spring)
Tulipa ‘White Triumphator’– (late spring)

Darwin hybrid tulips such as these are great multipliers:
Tulipa ‘Apeldoorn’– (midspring)
Tulipa ‘Apeldoorn’s Elite’– (midspring)
Tulipa ‘Beauty of Apeldoorn’– (late spring)
Tulipa Darwin Hybrid Mixed– (mid- to late spring)
Tulipa ‘Golden Apeldoorn’– (midspring)
Tulipa ‘Holland’s Glorie’– (late spring)
Tulipa ‘Oxford’– (midspring)
Tulipa ‘Striped Apeldoorn’– (late spring)

Also Good for Naturalizing

Brodiaea – Star flower (early summer)
Camassia cusickii – Quamash, Cusick camass (late spring)
Chionodoxa gigantea – Glory-of-the-snow (early spring). Need sun.
Chionodoxa luciliae – Glory-of-the-snow (early spring). Need sun.
Colchicum autumnale – Meadow saffron (autumn). Need sun.
Erythronium – Dog-toothed violet (spring). Good in shade.
Fritillaria meleagris – Guinea hen flower (spring). Very good at naturalizing.
Galanthus nivalis – Common snowdrop (late winter/early spring)
Ornithogalum umbellatum – Star of Bethlehem (early summer). Good in shade with some sun.
Puschkinia libanotica – Striped squill (spring)
Scilla campanulata Mixed – Spanish bluebells (spring)
Scilla siberica – Siberian squill (spring)