How to Plant, Grow, and Care For Spigelia (Pinkroot)

Spigelia is one of those perennials that’s the total package: showy blooms, pollinator resources, easy growing, and little to no maintenance. It’s also a U.S. native from the southeast and an adaptable grower with versatile applications.

Underutilized, Spigelia, or woodland pinkroot, brings lively color to the spring and early summer display with a sweep of red and yellow trumpets. Its ecological benefits and aesthetic appeal make it a prime addition to the partially shaded border.

Eye-catching and compact, the abundant blooms bring delight to hummingbirds, butterflies, and gardeners alike. Whether the straight species or its robust-blooming selections, we should explore pinkroot for our gardens. It earns its keep as a long-lived, easy bloomer.

What is Spigelia?

Spigelia marilandica is an herbaceous native perennial that blooms in mid-spring with sporadic flowering throughout the summer. The clumping, well-behaved, non-aggressive wildflower improves each year as roots strengthen and stems and blooms increase.

Classified as a threatened species in some areas, Spigelia is perhaps more popular in Europe than in its native homeland, according to plantsman Tony Avent of Plant Delights Nursery, who introduced high-performing selections of the species. But, its popularity is on the rise as gardeners discover and delight in these selections.

Pinkroot draws hummingbirds and pollinators from near and far with flowers that advertise their nectar and pollen. Arrange them in groups or en masse for a drift of the colorful wands. Pair them with hosta, columbine, phlox, baptisia, bluebells, and penstemon for an early summer show.

Perfect as a specimen in the perennial border, pinkroot is at home in woodland, native, wildflower, pollinator, rock gardens, and cottage arrangements. They also make excellent cut flowers in fresh florals. Fire-resistant and drought-resistant, the perennial grows across varying conditions.

Other species not in cultivation include S. gentianoides, or purpleflower pinkroot, native to Alabama and smaller in form with loads of soft lilac flowers. The species is federally endangered. S. texana, Texas pinkroot, is a white-flowering species listed as vulnerable by the state, and prairie pinkroot, S. hedyotidea, is uncommon in parts of north central Texas. Florida pinkroot, S. loganioides, is rare and endangered, with white to pale pink blooms.

Characteristics

Quick-growing in the spring, Spigelia forms a clump of upright stems topped with red, tubular blooms. The flowers face upward to reveal a starry, five-petaled yellow center. The trumpet blooms are two inches long and appear in clusters on one side of the stem, opening from the bottom up. When deadheaded and in favorable conditions, they bloom sporadically into August.

After flowering, seed capsules emerge, and in optimal conditions, they burst (dehisce) and scatter to yield seedlings. Tidy foliage is fresh in glossy, medium green, and the wedge-shaped leaves reach up to four inches long.

Spigelia is a member of the Loganiaceae (Logania) family, which houses notoriously poisonous species that contain strychnine. While pinkroot has an ethnobotanical history, it is toxic if ingested in quantity and contains the alkaloid spigiline. 

These wildflowers are carefree growers. They enter winter dormancy after fall’s hard freezes to reemerge in spring.

Native Area

S. marilandica originates in the southeastern United States, ranging from New Jersey down to Florida and west from Illinois south to Texas. The woodland growers occur on forested slopes, in moist woods, and on stream banks. They now occur in more isolated areas due to habitat loss. With hardiness across USDA zones 5 through 9, the perennials bear good heat and cold tolerance.

Planting

The dense wildflowers form clumps and reseed to expand the colony, though they aren’t vigorous spreaders. When planting, space them at least 12 to 18 inches apart to allow room to spread. They reach one to two feet wide at maturity.

Transplanting 

Fall and spring are the best times for planting. Like other perennials, they benefit from mild seasonal conditions like cool temperatures and moderate moisture to establish. Seedlings and transplants planted six weeks before the first frost have time to establish before winter conditions for spring flowering.

How to Grow

The low-maintenance wildflowers tolerate a range of conditions with little gardener intervention. They benefit from consistent moisture and sun exposure, depending on the climate, for best growth and flowering.

Light

Spigelia shows the most vigor in dappled light with morning sun exposure. In cool climates, it grows in full sun with regular moisture. It does best with protection from the afternoon sun in southern regions. A woodland edge or partially shaded bed is ideal.

Adaptable selections thrive across exposures, with more sun equating to increased growth and flowering. Plants in deeper shade show leggier stems with fewer flowers.

Water

The woodland native is drought-tolerant but does best with regular moisture. Even moisture during the growing season ensures overall health. Avoid prolonged wet and soggy conditions, as they lead to weakness and potential diseases.

Soil

The flowering perennials are adaptable to varying soil textures and pH levels, with slightly acidic as ideal. They prefer loose, loamy soils but tolerate lesser conditions as long there is good drainage.

At planting, topdress Spigelia generously with compost over the entire area, especially in poor soils like clay and sand. The organic material helps with aeration, moisture retention, drainage, and nutrition. 

Temperature and Humidity

The southern growers tolerate heat and humidity and moderate winter climates down to zone 5. They appreciate cool, moist spring seasons for growth and seeding. 

Seeds need cold and moist stratification to germinate, benefitting from six to eight weeks of winter temperatures before sprouting.

Fertilizing

After adding compost at planting, add another layer in spring to refresh the composition.

If you have poor soils and opt to fertilize, use one tailored to acid-loving plants like hollies, camellias, azaleas, and rhododendrons. These share similar pH favorabilities and growing requirements. Apply it in early spring to support new growth.

Maintenance

The extremely low-maintenance pinkroot doesn’t ask much in optimal conditions. Mulch around plants (away from stems) for insulation and moisture regulation. Deadhead spent blooms to prolong flowering.

For end-of-season care, cut back brown foliage and stems after leaves completely die back after fall’s first hard frost. Clip them when dry to tidy up.

Propagation

These perennials are easiest to propagate from seed and division. Commercial growers propagate them vegetatively, which can be tricky at home. To try cuttings, take them early in the season, before spring flowering, to promote rooting.

For those protected under a plant patient, propagation is illegal. Make sure to check your variety.

Growing From Seed

Collect seed capsules as they turn dark brown in the summer (usually in July) and before they split open. Place them in a paper bag for a few days until the capsules burst to expel the seeds.

Seeds require cold and moist exposure to germinate. Direct sowing them in the fall or winter gives them two or more months of natural cold stratification below 40°F (4°C).

Division

Divide established plants when they’re three years old or more. While division creates new plants, they don’t require it to thrive. The mother plant doesn’t lose vigor or rejuvenate through division like some other perennials.

Divide established specimens in early summer so new shoots can establish during the growing season. Loosen soil around the plants to capture and lift the entire root system. Rinse away the soil. Separate rhizomes from the mother plant by pulling them apart or using a spade or serrated blade. 

Recover the mother plant and install the divisions 12 to 18 inches apart in their new garden spots.

Popular Varieties

Top-performing selections of the native species make beautiful specimens. Look for them at your local nursery or from online growers that carry the specialties.

‘Little Redhead’

S. marilandica ‘Little Redhead’ has a more compact form than the species and is very floriferous. Bloom stalks rise from mid-May to July.

The tubular blooms are dark red with light yellow starry centers. Growers propagate these vegetatively for a uniform, true-to-type habit. From Plant Delights Nursery, the Pennsylvania Horticultural Society gave this one their Gold Medal Award.

‘Ragin Cajun’

S. marilandica ‘Ragin Cajun’ produces more flower heads on a mounded habit. The trumpet blossoms are brighter orange-red compared to the scarlet of other varieties.

Plant Delights and Juniper Level Botanic Garden in North Carolina introduced the selection in 2016. They discovered it on plant explorations near St. Francisville, Louisiana.

‘Apple Slices’

S. marilandica ‘Apple Slices’ has the darkest flowers of the varieties in deep wine red. Plants are self-cleaning and faded flowers naturally drop from the stem.

Introduced by Walters Gardens of Michigan and carried by Proven Winners, a plant patent protects this variety.

Common Problems

Spigelia is free of most pests and diseases. They may occasionally experience aphids and botrytis. The best control is prevention through maintaining optimal cultural requirements. 

Pests

Aphids are sap-sucking insects and prolific reproducers that feed on tissues. They’re pear-shaped and soft-bodied in light yellow, green, pink, brown, or black. They colonize in large numbers on the undersides of leaves. 

Aphids prefer soft, new growth, including tender shoots, leaf undersides, buds, and blooms. They don’t often pose a severe threat but can stress plants. They also leave behind sugary honeydew, leading to unattractive black, sooty mold. Severe infestation presents as curling and yellowing leaves and stunted growth.

Spraying a strong stream of water early in the day may deter aphids by displacing them from leaves and stems. The stream detaches the mouthparts of piercing insects from their bodies. Do this as part of ongoing maintenance.

Natural predators are the best line of defense. Attract ladybugs, parasitic wasps, hoverflies, and lacewings with diverse blooming selections.

Since aphids congregate in numbers, pruning off impacted sections may eliminate small populations. Horticultural soap or oil like neem controls infestations. Plant-based insecticidal oils include garlic extract, clove, rosemary, mint, and cinnamon oils and are effective organic controls. Follow label directions, as these treatments affect all insects, including pollinators. Time of day is essential in application.

To prevent aphids, water consistently to achieve evenly moist soils. The insects gravitate toward drought-stressed specimens over healthy, well-watered ones.

Diseases

Common fungal diseases are seldom issues but may occur in overly wet or humid conditions. Provide good air circulation and proper watering to promote overall health.

Botrytis cinerea is a blight where leaves and flowers discolor, and brown spots and “fluffy mold” appear. The fungus thrives in the cool, humid conditions of spring and fall and affects a wide range of plants, from ornamentals to food crops.

Neem oil is effective early on, as is potassium bicarbonate. Use a powdered formula mixed with water as a regular spray treatment,

Take care not to overwater or overfertilize, which weakens the plant and increases susceptibility. Space them for ample airflow and follow proper watering to avoid wetting the leaves unnecessarily. Remove fallen debris that can harbor spores.