Cup Plant

Silphium perfoliatum

Description & Overview

Attractive to us, attractive to wildlife; Cup Plant fosters a habitat with a native ecosystem and works in conjunction with the environment to create a full perennial hedge. The beautiful, large-yellow flowers have an analogous appearance to a Sunflower or a large, yellow Aster, and they will bloom for the hot months of the summer (July-September). At the peak of the season, this native can produce privacy which is uncommon for perennials. This maintenance-free plant will also make the perfect addition to a rain garden!

Core Characteristics

Mature Height: 7-8 feet
Mature Spread: 3-5 feet
Growth Rate: Perennial
Growth Form: Clumping
Light Requirements: Full Sun to Partial Shade
Site Requirements: Tolerant of clay, sandy, and loamy soils. Requires moist soil, however slightly drought-tolerant.
Flower: 3″ diameter, showy with 20-40 yellow rays.
Bloom Period: July- September
Foliage: Medium green leaves, ovate, coarsely-toothed, opposite. Many leaves lacking petioles.
Fall Color: Not Significant
Fruit Notes: Dry Seeds

Suggested Uses:

Cup Plant is a wonderful addition to any prairie, woods, bank, or butterfly garden. Reaching a large (tall) size for a perennial, this Wisconsin native brings a dominant vertical accent to any area. The blooms will open in a sunflower-like way during July and persist into September when the colder nights encourage the plant to seed. Cup Plant needs full sun and is easily propagated by seed collected in late September and October. Being tolerant of wet conditions, this is a perfect match for a rain garden or wet site. With the ability to grow to 8’ tall, Cup Plant has the power to over-crowd a smaller perennial garden. A central taproot will hold the large stalk steady while it spreads by shallow rhizomes to reproduce vegetatively.

The name “cup plant” comes from the physical characteristic the plant has with its’ middle leaves. If you look closely, you’ll see that there are no petioles and that the opposite leaves are attached to form a cup. This cup will catch rainwater and will be used by insects and birds for water and nesting.

Wildlife Value:

Cup Plant flowers provide a wonderful feast for native bees, it also provides a balanced structure and materials for bees to nest. The water caught in the cup-like leaves allows it to be used as a birdbath for native populations and the large seed head is quite attractive to birds. Cup Plant attracts hummingbirds, monarchs, skippers, moths, and a diversity of bees, wasps, and bee flies. Gold Finches are known to drink water from the cups and take shelter in the dense stems. Learn more about how to attract monarch to your yard.

Maintenance Tips:

Cup Plant is a maintenance-free, easy grower. You’ll know your cup plant has been successfully established in your landscape once it begins to produce seed. This may take a year or two; however, it will flourish after establishing. Stems can be cut back to the ground if the plant is encroaching other areas. Be sure to only prune a couple of stalks in a growing season because creating a wound can leave any plant vulnerable to infection. If in a drought, it may drop lower leaves until vigor can be returned to the upper leaves and flowers. Brown buds or leaves, stunted growth, and aborted blossoms are indications of stress. Again, it’s a maintenance-free plant, so first consider whether or not external factors (light, water, soil, etc.) are meeting this plant’s needs.


Cup Plant doesn’t have any major pests or diseases. Native wildlife, such as the Gall Wasp will feed within the stems of the leaves. This can attract a parasitic wasp; however, this process will not affect the health of the plant.

Since it’s a tall, leggy plant, strong winds may cause it to fall over, this can also occur from the weight of the blooms. This is a normal characteristic of the plant and can either be left alone, or you may attempt to stake the plant.

Leaf Lore:

The genus name Silphium comes from the Greek word for ‘Silphion’, a plant also known as ‘laserwort’ or ‘laser’. The resin that exudes from the stems of this genus was once made into chewing gum to prevent nausea and vomiting. Perfoliatum is said to be translated to “leaf surrounding or embracing the stem”. This family of plants was found by Carl Linnaeus, an 18th century Swedish Botanist and the developer of the binomial nomenclature of modern taxonomy.

Companion Plants:

Cup Plant is a great plant for a large, wetland garden, and can be paired with other tall natives, like Ironweed, Joe-Pye Weed, Meadow Rue, Spiderwort, Wild Quinine. It can be accented with shrubs like Gray Dogwood or trees like Black Cherry to really befriend all the birds. Some smaller perennials that would look great in front of the Cup Plant are: Wild Bergamot, Wild Geranium (Geranium maculatum), Prairie Smoke, Anise-Hyssop, and there are many more. Cup Plant makes a great backdrop for a perennial garden or an integral piece of a wetland hedge.

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