Perennial plants can make a gardener's life much easier. Beds don't have to be replanted, much of the structure of the garden remains throughout the year and plants don't have to be purchased annually.

By definition, a perennial is a plant that lives for more than two or three years. But just how perennial is that perennial you just planted?

Many wonderful perennials survive only two or three years. Still, we plant them happily and hope they will continue on by reseeding themselves. Examples include: baby's breath, blanket flower, delphinium, Dianthus, hybrid tulips, lavender, penstemon and Scabiosa.

Other perennials are old reliables we can trust to carry on year after year. For shade, hostas and ferns are dependable comebacks.

Not surprisingly, many of the longest-lived perennials for sun are deep-rooted grasses and prairie plants. They may not look like much in garden centers early in spring, maybe not even the first year or two they're in the ground, but they'll pay off in the long-term. If you're thinking years or even decades into the future, here's some to consider:

Culver's root, Veronicastrum virginicum, is a very tall erect perennial with spikes of small, white tubular flowers in July-August. Native to open woods and moist meadows, it prefers moist, well-drained soil in full sun or light shade.

Queen of the meadow, Filipendula ulmaria, has fragrant, creamy-white astilbe-like flowers that bloom from early summer into fall. Full to part sun.

Dwarf blue indigo, Baptisia minor, has beautiful blue flowers in spring and rich brown seed pods that are great for dried arrangements.

Skullcap, Scutellaria scoridifolia 'Mongolian Skies', is very drought-tolerant. Blue/purple flowers in early summer will return if deadheaded.

New Jersey tea, Ceanothus americanus, is a native shrub with clusters of white flowers.

Butterfly milkweed, Asclepias tuberosa, has dark orange-red flower clusters in summer and attractive seed pods in fall. Plant in full sun in dry soil or raised bed.

Pale purple coneflower, Echinacea pallida, is a sweet-scented coneflower with spidery petals that blooms June-July. Also a long-lasting cut flower.

Tennessee coneflower, Echinacea tennesseensis, is an adaptable, deep-rooted coneflower with bright, uplifted petals.

Spike gayfeather, Liatris spicata 'Kobold' grows to two feet in height and has deep purple spikes.

Other long-lived perennials include aster, astilbe, balloon flower, bee balm, bleeding heart, Campanula, catmint, daffodil, daylily, evening primrose, hardy geranium, iris, Joe-pye weed, lady's mantle, Lamium, leadplant, Lenten rose, peony, red hot poker, black-eyed Susan, sedum and yarrow.

If you want to cast your vote about short- and long-lived perennials, fill in a quick survey at arboretum.unl.edu, and we'll share the information in next month's "In the Garden."

"In the Garden" is provided by the Nebraska Statewide Arboretum. A podcast of "In the Garden" is available at the Arboretum Web site, www.arboretum.unl.edu. Click on the podcast icon on the homepage.