Black Truffle Cardinal Flower

Black Truffle Cardinal Flower

Black Truffle Cardinal Flower is a selection of the native cardinal flower, Lobelia cardinalis, chosen for its dark foliage. Leaves emerge nearly black in late spring and mature to a glossy deep maroon and purple, holding their color until hard frost. Upright, bushy stems form a clump about 3–4 feet tall and 2–3 feet wide. It was selected in Pennsylvania from open-pollinated cardinal flower seedlings over about ten years of trials.

From midsummer into early fall, tall terminal spikes open bold, deep red tubular flowers from the bottom up. The red blooms stand out sharply against the dark leaves. Hummingbirds visit the flowers heavily, along with swallowtail butterflies and large bees. The spikes also make long-lasting cut flowers. In the landscape it suits rain gardens, pond and stream edges, wet meadows, and the middle or back of moist borders, and it works as an accent in large containers.

Black Truffle grows in full sun to partial shade, with afternoon shade helpful during hot summers. It needs rich, organic soil that stays moist to wet and should never dry out; it tolerates brief flooding, which makes it useful in low spots where many perennials fail. Deer tend to leave it alone. Clumps persist through basal offsets, and individual plants may live only a few seasons. Steady moisture is the key to success.

Care Instructions:

Planting: Plant in spring or early fall in a site that stays moist, such as a rain garden, pond edge, or low area of a border, setting the crown at soil level.
Soil: Prefers rich, organic soil of any texture that holds moisture; work in compost where soil is sandy or lean.
Watering: Keep the soil consistently moist from planting onward and water deeply during dry spells, since plants decline quickly when the soil dries out.
Fertilizing: Apply compost or a light balanced fertilizer in spring as new growth begins; rich soil usually provides enough nutrients.
Pruning: Cut spent flower spikes back to the foliage after bloom, and remove old stems in late fall or early spring once the basal rosettes are visible.
Spacing: Space plants approximately 12–18 inches apart; the clumps will meet and form a continuous band of dark foliage and red spikes.
Maintenance: Keep mulch, leaves, and debris off the low winter rosettes so they are not smothered, and replace plants that fail to return in spring.

Gardeners choose Black Truffle for the contrast of red flowers over nearly black leaves, a combination that holds interest long before and after bloom. As a native cardinal flower, it supports hummingbirds during late summer migration. It performs best in consistently moist, sunny to partly shaded sites, where it pairs well with ferns, blue lobelia, and other moisture-loving natives that share its preference for wet ground.

Landscape Solutions:

• Tolerance of wet soil and brief flooding makes it a strong choice for rain gardens, downspout areas, and other low, soggy spots.
• Bright red tubular flowers from midsummer into early fall provide nectar for hummingbirds in pollinator and native gardens.
• Nearly black foliage adds dark color and contrast among green, gold, and silver plants for months before and after bloom.
• Deer tend to avoid it, which helps it hold up in yards where browsing damages other perennials.
• Its upright clumps soften the edges of ponds and streams where many garden plants cannot handle saturated soil.