Silphium terebinthinaceum - Prairie Dock

Silphium terebinthinaceum, commonly known as Prairie Dock, is a bold herbaceous perennial that produces tall, airy stems topped with bright yellow, daisy-like flowers. The blooms rise well above a dramatic basal clump of very large, rough-textured, heart-shaped green leaves, creating a strong architectural presence in the garden. Blooming from midsummer into early fall, this plant adds height, texture, native charm, and valuable late-season colour to borders, prairie gardens, meadow plantings, pollinator gardens, or naturalized perennial beds.

Thrives in well-drained soil with dry to medium moisture. Avoid planting in heavy, waterlogged conditions, though established plants are highly tolerant of drought. Requires minimal maintenance once established and develops a deep taproot, so it is best planted where it can remain undisturbed. Deadhead spent blooms for a tidier appearance, or leave seed heads for wildlife value and natural winter interest. Pairs well with echinacea, rudbeckia, liatris, monarda, asters, and ornamental grasses for a bold, naturalistic garden display. Attracts bees, butterflies, and other beneficial insects. Generally avoided by deer and rabbits. Excellent for native plant gardens, prairie-style landscapes, sunny borders, pollinator plantings, meadow gardens, or large naturalized areas. Silphium terebinthinaceum is a striking and long-lived native perennial that thrives in sunny gardens, adding massive foliage and tall yellow flower stems with strong ecological value. Its drought tolerance, architectural form, and pollinator appeal make it a valuable choice for low-maintenance, wildlife-friendly, and naturalistic landscapes.

Sun Requirements:

Full Sun. Performs best in full sun, where it develops the strongest stems, largest foliage, and most abundant flowering.

Maximum Growth Height:

72–120 inches (180–300 cm), with a spread of about 24–36 inches (60–90 cm).

Bloom Month:

July to September. Blooms from midsummer into early fall, producing tall stems of bright yellow daisy-like flowers that provide strong seasonal colour and attract many beneficial pollinators.