Description & Overview

An herbaceous perennial that grows up to a height of six feet, sometimes more, Rosinweed is a towering and regal plant native to the southern third of Wisconsin. Standing tall and proud, it is found in dry-mesic to wet-mesic prairies, in clay to gravelly prairies, and in mesic meadows. Sturdy stems bear coarse green leaves that rise in late spring to show off bright golden yellow blossoms. Bumble bees, butterflies, and moths are attracted to the flowers, and once those have passed, songbirds relish the seeds. Rosinweed may also be known as Prairie Rosinweed or Whole-leaf Rosinweed.

Core Characteristics

Category: Perennial

Wisconsin Native: Yes

USDA Hardiness Zone: to zone 4

Mature Height: 2-6 feet

Mature Spread: 2-3 feet

Growth Rate: Fast

Growth Form: Erect, clump - forming

Light Requirements: Full Sun

Site Requirements: Dry to wet moisture, well - drained

Flower: Yellow, sunflower - like, 2 - 3" wide, 16 - 33 rays, many heads

Bloom Period: July – September

Foliage: Medium green, opposite, 3 - 6", rough

Fall Color: None

Urban Approved: Yes

Fruit Notes: Egg - shaped achene, 3/8", Sept - mid - October

Suggested Uses

While preferring dry conditions and full sun, Rosinweed is adaptable and not fussy. A deep taproot means it has decent drought tolerance, requiring less water than other non-prairie plants.

This is a great plant for both novice and master gardeners. Cheery yellow flowers that bloom in mid-summer are welcomed by bees and butterflies alike and seeds are a bird favorite in fall, making Rosinweed an excellent addition to a wildflower, wildlife, or pollinator garden. Rosinweed competes well with most prairie grasses and forbs and is a great option in a prairie restoration project or tall-grass prairie setting.

Rosinweed grows more quickly than many other members of the genus, such as Prairie Dock (Silphium terebinthinaceum) or Compass Plant (Silphium laciniatum), and is less aggressive in the landscape than Cup Plant (Silphium perfoliatum).

Strong stems help keep this plant erect and because of this, they make great cut flowers.

An herbaceous perennial that grows up to a height of six feet, sometimes more, Rosinweed is a towering and regal plant native to the southern third of…

Wildlife Value

Visitors seeking nectar and pollen include the Eastern Tiger Swallowtail (Papilio glaucus), Fiery Skipper (Hylephila phyleus), Clouded Sulphur (Colias philodice), Painted Lady (Vanessa cardui), and Monarch (Danaus plexippus). Honeybees (Apis mellifera), bumble bees (Bombus spp.), Little Carpenter bees (Ceratina spp.), Cuckoo Bees (Triepeolus spp.), Long-horned bees (Melissodes spp.), Leafcutter bees (Megachile spp.), Green Sweat bees (Agapostemon spp.), and Hoverflies will also frequent the nutritious flowers.

It is a host plant to the Rosinweed Moth (Tebenna silphiella) and Giant Eucosma Moth (Eucosma giganteana).

Ruby-throated hummingbirds will also visit the flowers.

The seeds are a favorite of Gold Finches, Sparrows, Chickadees, and Redpolls.

The Apical Rosinweed Gall wasp (Antistrophus silphii) will form galls at the top of the flower stalks. This gall wasp attracts a parasitic wasp, Eurytoma lutea, which feeds on the larvae of the gall wasp.

Maintenance Tips

As with all Silphium, Rosinweed forms a deep taproot. Site this plant with care as they do not transplant well.

In optimal growing conditions, this plant will readily reseed. If this is not desired, deadhead after blooming.

An herbaceous perennial that grows up to a height of six feet, sometimes more, Rosinweed is a towering and regal plant native to the southern third of…

Pests/Problems

Black Walnut Tolerant: Yes
Deer Resistant: No
Rabbit Resistant: Yes

Rosinweed has few diseases and is easy to grow. Powdery mildew, leaf spots, and rust can be potential problems however, they can be avoided by planting in an area with plenty of air circulation in well-draining soil.

The coarse leaves and flower height protect this plant from small herbivores such as rabbits, but cattle will readily eat Rosinweed.

Leaf Lore

The genus name Silphium is Greek for silphion, a plant native to northern Africa. The specific epithet integrifolium is Latin and means “having entire or uncut leaves.”

While somewhat similar looking to sunflowers (Helianthus spp.), Rosinweed differs in that its disk florets are sterile while the ray florets are fertile. It is the opposite for sunflowers.

Reaching upwards of six feet tall, Rosinweed is the shortest member in the Silphium genus, with Prairie Rosinweed or Dock growing more than 10′ tall!

Rosinweed and Cup plant (Silphium perfoliatum) can hybridize.

The sap of this plant contains a fragrant resin that has a slightly bitter taste and is likened to frankincense or turpentine.

Research is being done on Silphium integrifolium and its use as an oilseed. Studies have determined that it has the potential to be at least as productive as sunflowers in the proper conditions.

Traders were said to have chewed the resin to clean their teeth and mouths. The Mesakwai people used Rosinweed medicinally, steaming the roots to treat pain while leaves were infused to help bladder ailments.

Companion Plants

Combine this tall beauty with those that enjoy similar site conditions. Options include Big Bluestem (Andropogon gerardii), Wild Senna (Cassia hebecarpa), Ironweed (Vernonia fasciculata), Rattlesnake Master (Eryngium yuccifolium), Culver’s Root (Veronicastrum virginicum), Purple Prairie Clover (Dalea purpurea), Stiff Coreopsis (Coreopsis palmata), Switch Grass (Panicum virgatum), Golden Alexanders (Zizia aurea), Purple Coneflower (Echinacea purpurea), Prairie Dock (Silphium terebinthinaceum), and Wild Quinine (Parthenium integrifolium).

An herbaceous perennial that grows up to a height of six feet, sometimes more, Rosinweed is a towering and regal plant native to the southern third of…
beth delain1 avatar

Written by Beth DeLain