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How to Care for Cup Plant

Updated: July 8, 2022

Cup plant (Silphium perfoliatum) is a native plant in North America that produces stunning yellow flowers in late summer. It is named after the unique shape of its leaves, which are fused around the stem to form a cup-like structure that can hold rainwater. Cup plant is a great addition to any garden or landscape as it attracts pollinators and birds with its nectar-rich flowers and seeds.

If you’re planning on growing cup plants in your garden, there are a few things you need to know about caring for them. Here’s a guide on how to care for cup plant.

Soil Requirements

Cup plants prefer moist soils with good drainage. They can tolerate a range of soil types, including clay, loam, and sandy soils. However, they do not like dry or waterlogged soils. If your soil is too dry, water the plant regularly to keep the soil moist. If the soil is too wet, improve drainage by adding organic matter such as compost or peat moss.

Light Requirements

Cup plants thrive in full sun to partial shade. They require at least six hours of direct sunlight every day to grow and produce flowers. If you’re planting them in a shady area, make sure they receive at least four hours of direct sunlight every day.

Watering Requirements

Cup plants require regular watering, especially during dry spells. Water them deeply once a week or more frequently if the soil feels dry to the touch. Do not overwater as this can cause root rot.

Fertilizing Requirements

Cup plants do not require fertilizers as they can grow well in nutrient-rich soils. However, if your soil lacks nutrients, you can apply a balanced fertilizer once a month during the growing season.

Pruning Requirements

Cup plants do not require pruning except for removing dead or damaged stems. You can cut back the plant to the ground in late fall or early spring to encourage new growth.

Pests and Diseases

Cup plants are relatively pest and disease-free. However, they can be affected by powdery mildew, a fungal disease that causes a white powdery coating on the leaves. To prevent powdery mildew, water the plant at the base and avoid getting the leaves wet. If you notice powdery mildew on your plant, remove affected leaves and dispose of them in the trash.


Cup plants can be propagated by dividing the root ball in early spring or fall. Dig up the plant and gently separate the roots into several sections using a sharp knife. Replant each section in a new location or container.


How big do cup plants grow?

Cup plants can grow up to 8 feet tall and 4 feet wide.

When do cup plants bloom?

Cup plants bloom from late summer to early fall.

Do cup plants attract pollinators?

Yes, cup plants attract bees, butterflies, and hummingbirds with their nectar-rich flowers.

Can cup plants tolerate drought?

Cup plants prefer moist soils but can tolerate short periods of drought.

Are cup plants invasive?

Cup plants can spread easily through self-seeding but are not considered invasive.

In conclusion, caring for cup plants is easy as long as you provide them with adequate moisture, sunlight, and well-draining soil. They can add beauty to your garden while attracting pollinators and birds. With proper care, your cup plant will thrive for years to come.