Asiatic lilies are low-maintenance perennials that provide graceful blooms and long-lasting cut flowers. They bloom from late June to the middle of July and most are hardy to USDA Zone 3. That leaves them standing headless in the garden for another three months in most places until their leaves have done their job and wilt back. Use companion plants to provide a succession of bloom that will complement the Asiatics in your garden.
Division I, or Asiatic lilies, are hybrids of various species lilies. They have the widest variety of colors; whites, yellows, oranges, reds, violets and various mixtures. They may be freckled or plain. They are often up-facing but may be outfacing or hang in Turk’s caps or pendants. They are the longest-blooming of all the lilies. Although they do not all bloom at the same time, one variety or another is in bloom over a month of early summer. They grow in brightest sunshine but bloom well in light shade, too. These elegant, undemanding plants are the perfect choice for the beginning perennial gardener.
Asiatic lilies plant their feet deep. Bulbs planted 4 to 6 inches below the surface pull themselves downward as they grow larger. Because they “sit” so deep, a variety of shallow-rooted plants can be interplanted with them. Asiatic lilies prefer slightly acidic, very well-drained garden soil that's just the right environment for most garden perennials. Asiatics grow from 2 to 4 feet tall, rising above many peonies and leaving room for shorter plants to shine.
Other lilies make good companions if they extend the bloom of Division I lilies. Division VI (trumpet and Aurelian hybrids) bloom mid to late summer but are not as cold hardy. Division VII oriental lilies are the latest bloomers but require partial shade and mulch for cool roots. Division VIII hybrids are later bloomers, descending from trumpet, Aurelian and oriental lilies. Like the Asiatics, they are hardy and dependable. Tiger lily, a native American species lily, blooms last of all atop 6-foot stalks. Although all types are not hardy to USDA Zone 3, most are hardy to Zone 4 and, with the appropriate light, coexist easily together.
Most annuals have shallow roots and bloom later than lilies. Snapdragons, rudbeckia, sweet peas or any annual that likes moist, well-drained, slightly acidic soil will make a good companion. Peonies, iris and columbine are all shallow-rooted plants that will precede lily blooms. Gladiolus is shallow-rooted and will not overgrow lilies until after they are finished blooming. In warmer zones, cannas or torch lilies can be added as midsummer companions.
Daylilies and hostas are hardy summer-blooming companions but hostas should be slug-resistant varieties. Dahlias, campanula, coreopsis, dianthus and Shasta daisies make good summer-flowering companions clustered around the tall, leafy lily stalks. Chrysanthemums and asters provide late-season color to finish the succession of bloom and mask lily stalk bases as they begin to brown.