previous
  • Dwarf Citrus Trees
    Dwarf Citrus Trees
  • In Pursuit of the Perfect Potting Shed
    In Pursuit of the Perfect Potting Shed
  • Slideshow: Beautiful Clematis
    Slideshow: Beautiful Clematis
  • Colorful Selections for Shade
    Colorful Selections for Shade
  • Plant an Easy-to-Water Strawberry Jar
    Plant an Easy-to-Water Strawberry Jar
  • Make a Succulent Topiary
    Make a Succulent Topiary
  • Indeterminate or Determinate Tomatoes?
    Indeterminate or Determinate Tomatoes?
  • Comfortable Alfresco Dining
    Comfortable Alfresco Dining
  • Designing with Curved Terraces
    Designing with Curved Terraces
  • Save Money by Growing Your Own
    Save Money by Growing Your Own
  • Containers as Focal Points
    Containers as Focal Points
  • Homegrown / Homemade
    Homegrown / Homemade
  • NEW Video Series: There's a Better Way
    NEW Video Series: There's a Better Way
  • Building a Compost Bin
    Building a Compost Bin
  • Garden Confidential: A Plant Walks into a Bar
    Garden Confidential: A Plant Walks into a Bar
  • Elephant's Ears
    Elephant's Ears
  • Mulch for a Healthy Garden
    Mulch for a Healthy Garden
  • Meet Our Mini-Magazines
    Meet Our Mini-Magazines
  • Fragrant Plants for Pathways
    Fragrant Plants for Pathways
  • Thoughts From a Foreign Field
    Thoughts From a Foreign Field
  • Fast-Growing Trees for Impatient Gardeners
    Fast-Growing Trees for Impatient Gardeners
  • 6 Tips for Weed Control
    6 Tips for Weed Control
  • Pretty in Pink
    Pretty in Pink
  • Stylish Shady Containers
    Stylish Shady Containers
  • Fine Gardening's Tip Off!
    Fine Gardening's Tip Off!
next
Find a plant:

OR Browse All Plants


Genus Silphium (Prairie dock, Rosinweed)

Silphium Silphium perfoliatum Photo/Illustration: Michelle Gervais
SILL-fee-um Common Name: Prairie dock, Rosinweed
These perennials are native to prairies and open woods of Canada and the central and eastern U.S. They have daisy-like, yellow blossoms and resinous sap that is harshly scented. Their height makes them suited to the back of a border, native garden, or naturalistic plantings.
 Noteworthy characteristics: These tall native plants offer perennial, sunfloweresque blossoms to gardens and wilder settings.
 Care: Grow in moist, neutral to slightly alkaline soil (preferably heavy soil) in full sun to partial shade.
 Propagation: Sow seed in containers when fresh; divide in spring.
 Problems: Rust, downy mildew, Cercospora leaf spot.

Species, varieties and cultivars for genus Silphium

Silphium laciniatum Silphium laciniatum
(Compass plant, Pilot plant, Polar plant) (1 user review)
Hardiness Zones: 1 2 3 4 5 6 7 8 9 10 11

This tall, sturdy prairie plant makes an imposing statement in the garden with its large, deeply cut leaves and yellow sunflower-like flowers that face east and bloom in late summer and early fall. The leaves of the compass plant can grow up to 18 inches long and are deeply incised with a shape that looks like something from a painting by Matisse. They align themselves on a north-south axis to conserve moisture by avoiding the midday sun. This plant requires a few years to enlarge and flower, but once its deep roots are anchored, it will live for many years.
Silphium perfoliatum Silphium perfoliatum
(Cup plant) Be the first to rate this plant
Hardiness Zones: 1 2 3 4 5 6 7 8 9 10 11

A coarse but bold perennial giant for the back of the border with yellow, daisy-like flowers in summer. Cups form where the toothed leaves meet the thick stems; birds are said to drink from the water held in the cups. Tough prairie natives that will self-sow, these plants need lots of sun and lots of room—a single plant can reach 7 or 8 feet tall and 6 feet across.