Spring ephemeral plants are popular in gardens and landscapes across the world and have been for centuries. American ephemerals especially are gaining admiration by gardeners and collectors.
Native ephemerals bring early season color and life into the garden. They occur naturally in shaded, moist woodlands. Often, these woodlands have slightly acidic, rocky soils that are rich in organic matter. Those who live in woodlands or have shaded gardens are likely to be the most successful in gardening with many of these species.
Moist, slightly acidic sandy loams and humusy soils, rocky or gravely soils, and rock gardens in full to part shade are ideal conditions for most of these species. In general, soils should be consistently moist but not wet or soggy. Since many of these species have bulbs, corms, or other underground storage organs they generally grow best in soils with good drainage. Heavy clay soils and soils that remain very soggy or wet are often not suitable for growing most of the ephemerals because bulbs and other storage organs will rot.
Avoid planting ephemerals in areas that receive hot, afternoon sun as well as areas that tend to dry out quickly. Some gardeners who wish to grow some of the popular ephemerals may benefit from amending their garden soils to meet the plants’ needs. Chopped, sphagnum peat moss is a great soil amendment for many woodland ephemerals because it retains moisture, adds organic material to the soil, and is naturally acidic. Add a small amount – no more than 10% of the overall soil. Composted leaves, pine needles and bark, leaf mold, and garden compost are also suitable soil amendments. Avoid using fresh manure or grass clippings as soil amendments.
Since the time the ephemerals shine in the garden is short and seasonal, mix them with species that bloom longer, later, or have season-long interest. Some native spring and summer bloomers suitable for shady gardens that make good companions to the ephemerals include creeping phlox (Phlox stolonifera), woodland phlox (Phlox divaricata), Indian pinks (Spigelia marilandica), lilies (Lilium sp.), violets (Viola sp.), nodding onion (Allium cernuum), wild bleeding heart (Dicentra eximia), cohosh (Actaea sp.), beardtongue (Penstemon sp.), green-and-gold (Chrysogonum virginianum), blue-eyed grass (Sisyrinchium sp.), eastern columbine (Aquilegia canadensis), catchflies (Silene sp.), and dwarf crested iris (Iris cristata).
Plants to compliment the ephemerals with attractive, persistent foliage include pussytoes (Antennaria sp.), woodland stonecrop (Sedum ternatum), Allegheny spurge (Pachysandra procumbens), wild live-forever (Hylotelephium telephoides), alumroot (Heuchera sp.), foamflower (Tiarella cordifolia), sedges (Carex sp.), as well as ferns and mosses.
For smaller ephemeral species, such as Hepaticas, trout lilies, Claytonia, and Dicentras, a position towards the front of a garden or border may be ideal so they are not lost among larger perennials. Rocky crevices in woodlands, rock gardens, or lightly-treaded pathways may also make suitable planting options. Allow spreading ephemerals to fill in under larger trees and shrubs, where they can remain green and attractive for as long as possible. Mayapples, bloodroot, bluebells, ramps, Dicentras, and Jack-in-the-pulpit will spread slowly over time either through seed or rhizomes to create a groundcover. Trilliums, wild hyacinth, and shooting star really shine when planted in masses. Plant them near masses of plants with later-season interest, or within a short groundcover.