Perennials are plants that live three or more years, die in the ground each fall and return in the spring. Short –lived perennials are those that live three to five years; long lived perennials live indefinitely. Perennials can be grown in nearly any garden location – sunny, shady, wet, dry, border or background. Iowa State University Extension and Outreach horticulture specialists recommend perennials to meet specifications of many gardeners. To have additional questions answered, contact the Hortline at 515-294-3108 or firstname.lastname@example.org.
All perennials require some maintenance. Watering, fertilizing, pinching, staking, deadheading, dividing and providing winter protection are common maintenance chores. Some perennials require frequent attention through the growing season. Others require minimal care.
Low maintenance perennials for sunny locations include butterfly weed (Asclepias tuberosa), false blue indigo (Baptisia australis), hardy geranium (Geranium spp.), hardy zinnia (Heliopsis helianthoides), daylily (Hemerocallis spp.), Siberian iris (Iris sibirica), blazing star (Liatris spp.), daffodil (Narcissus spp.), peony (Paeonia hybrids), Russian sage (Perovskia atriplicifolia), moss phlox (Phlox subulata), balloon flower (Platycodon grandiflorus), coneflower (Rudbeckia spp.), perennial salvia (Salvia x superba), sedum (Sedum spp.), speedwell (Veronica spp.) and ornamental grasses (various species).
Low maintenance perennials for partial to heavy shade include lady’s mantle (Alchemilla mollis), Canadian wild ginger (Asarum canadense), heartleaf brunnera (Brunnera macrophylla), turtlehead (Chelone spp.), bleeding heart (Dicentra spp.), barrenwort (Epimedium spp.), hosta (Hosta spp.), creeping phlox (Phlox stolonifera), lungwort (Pulmonaria spp.), bloodroot (Sanguinaria canadensis), foam flower (Tiarella spp.) and ferns (various species).
When selecting perennials, it’s important to choose plants that are suitable for the planting site. Perennials that grow well in moist to wet soils include sweet flag (Acorus calamus), Jack-in-the-pulpit (Arisaema triphyllum), goat’s beard (Aruncus dioicus), swamp milkweed (Asclepias incarnata), turtlehead (Chelone species), black snakeroot (Actaea racemosa), Joe-pye weed (Eupatorium purpureum), queen-of-the-prairie (Filipendula rubra), rose mallow (Hibiscus moscheutos), Japanese iris (Iris ensata), yellow flag (Iris pseudacorus), cardinal flower (Lobelia cardinalis), obedient plant (Physostegia virginiana) and spiderwort (Tradescantia species).
Excellent groundcovers for shade include bugleweed (Ajuga spp.), wild ginger (Asarum canadense and A. europaeum), barrenwort (Epimedium spp.), sweet woodruff (Galium odoratum), hosta (Hosta spp.), spotted deadnettle (Lamium maculatum), creeping lily-turf (Liriope spicata), Japanese pachysandra (Pachysandra terminalis), lungwort (Pulmonaria spp.), foam flower (Tiarella cordifolia) and vinca (Vinca minor).
Variegated bishop’s weed (Aegopodium podagraria ‘Variegata’) and lily-of-the-valley (Convallaria majalis) are two other shade-tolerant groundcovers. Unfortunately, both plants spread rapidly and often become invasive. These aggressive spreaders should not be planted with other perennials as they quickly crowd out neighboring plants. Variegated bishop’s weed and lily-of-the-valley should only be planted in areas where they can be confined (for example, between a building and sidewalk) or allowed to spread freely.
Native woodland wildflowers that make good additions to the home landscape include wild columbine (Aquilegia canadensis), Jack-in-the-pulpit (Arisaema triphyllum), goat’s beard (Aruncus dioicus), Canadian wild ginger (Asarum canadense), Dutchman’s breeches (Dicentra cucullaria), shooting star (Dodecatheon meadia), Virginia bluebells (Mertensia virginica), woodland phlox (Phlox divaricata), May apple (Podophyllum peltatum), Solomon’s seal (Polygonatum biflorum), bloodroot (Sanguinaria canadensis), false Solomon’s seal (Maianthemum racemosum), merrybells (Uvularia grandiflora) and others.