Starry rosinweed (Silphium asteriscus)

Also known as: Starry Rosinweed, Starry Sunflower, Prairie Star

Starry rosinweed (Silphium asteriscus) exhibits several distinctive features and adaptations that enable it to flourish in prairie environments:

1. **Distinctive Flowers and Stems**: The plant is recognized for its star-shaped yellow blossoms and robust, upright stems, which typically bloom in late summer.
2. **Leaf Arrangement**: It features heart-shaped leaves with toothed edges, arranged in a basal rosette.
3. **Deep Root System**: The extensive root system penetrates deeply into the soil, allowing the plant to access water and nutrients from lower soil layers, providing drought resistance.
4. **Soil and Water Adaptation**: It thrives in dry, well-drained soils common to prairie habitats.

These traits make starry rosinweed well-suited to the challenging conditions of prairie ecosystems.

In This Article

Care Tips Water Sunlight Temperature Soil Fertilize Prune Propagation Repotting

Attributes of Starry rosinweed

Lifespan

Perennial

Plant Type

Herb

Plant Height

61 cm to 1.5 m

Spread

45 cm to 90 cm

Leaf Color

Green

Flower Size

2-3 inches

Flower Color

Bright yellow

Images of Starry rosinweed

Quickly Identify Starry rosinweed

Robust stature reaching 3 feet (91 cm) tall as a herbaceous perennial.

Lemon-yellow flower heads, 1.5 inches (4 cm) in diameter, resembling silver dollars.

Bright yellow flowers, 2-3 inches (5-7.5 cm) wide, with vibrant, daisy-like petals.

Dry, one-seeded achene fruit, brown and ridged, 0.1 inches (2-3 mm) long.

Papery involucre enclosing fruit, providing a distinctive texture.

Scientific Classification of Starry rosinweed

Phylum

Vascular plants

Class

Dicotyledons

Order

Asterales

Family

Daisy

Genus

Rosinweeds

Species

Starry rosinweed

Planting and Growing of Starry rosinweed

Care Difficulty

Easy

Watering Schedule

Every 3 days

Sunlight Requirements

Full sun

Sunshine Duration

6-10 hours

Ideal Temperature

65-80℉

Soil Type

Potting Mix, Peat Mix

Soil pH

6.5-7.5

Fertilizer Type

Balanced

Pruning Season

Spring, Summer

Pruning Area

Branches, Leaves

Pruning Frequency

2 times a year

Repotting Season

Spring

Pot Type

Plastic, Ceramic

How to Water Starry rosinweed?

Silphium asteriscus requires moderate watering, where you should aim to provide approximately 250 milliliters per watering session. The soil should be slightly moist, but not soggy. Be attentive to drainage and ensure water reaches the roots without pooling on the surface.

What are the symptoms of an underwatered Starry rosinweed? ›

What should I do if my Starry rosinweed is not getting enough water? ›

What are the symptoms of an overwatered Starry rosinweed? ›

How to save an overwatered Starry rosinweed? ›

What Are the Sunlight Requirements for Starry rosinweed?

Sunlight Requirements: Full sun, Partial sun

Duration of light: 6 to 8 hours

Silphium asteriscus ideally requires full sun or partial sun conditions. This ensures optimal photosynthesis efficiency, promoting robust growth, vibrant foliage, and prolific flowering.

What type of sunlight does Silphium asteriscus prefer? ›

How can I ensure ideal lighting for Silphium asteriscus? ›

What are the benefits of providing ideal lighting? ›

What Is the Ideal Temperature Range for Starry rosinweed?

Ideal Temperature: 65 ~ 80℉

The ideal temperature range for Silphium asteriscus is between 65°F to 80°F. Within this range, the plant can perform photosynthesis effectively and maintain optimal growth. Ensuring these temperatures during the active growing season aids in developing healthy foliage and a robust flowering process.

What Soil is Best for Starry rosinweed?

Soil type: Sandy loam, Loam

Soil PH: 6.5 ~ 7.5

Silphium asteriscus thrives best in soils that are well-draining to prevent root rot. Good drainage helps maintain optimal moisture levels, ensuring robust root development and healthy plant growth. A nutrient-rich soil is essential, promoting vigorous growth and vibrant flowering. It supports the plant by providing necessary macro and micronutrients, enhancing its resistance to pests and diseases. Inclusion of moderate organic matter improves soil structure and water retention without causing excessive dampness, benefiting Silphium asteriscus by providing a balanced environment for its roots.

How to Fertilize Starry rosinweed?

Fertilizer type: Balanced

For Silphium asteriscus, application of fertilizer should be done cautiously to avoid over-fertilization. A general recommendation is to apply a balanced liquid fertilizer at half the strength every two weeks during the growing season. For slow-release fertilizers, use 1/2 to 1 pound per 100 square feet at the beginning of the growing season. This ensures healthy growth without overwhelming the plant.

How to Prune Starry rosinweed?

Pruning Time: Spring, Summer, Autumn

Carefully trim off any dead or damaged stems at a 45-degree angle, just above a leaf node. This encourages new, healthy growth and ensures that the plant remains attractive and vibrant throughout the growing seasons. If Silphium asteriscus becomes too tall or ungainly, reduce its height by about one-third. This helps maintain the plant's structural integrity and prevents it from becoming top-heavy or flopping over. More About Pruning Techniques→

How to Propagate Starry rosinweed plant?

Propagate Time: Spring, Early summer

Choose healthy and mature seeds for propagation. Avoid seeds that appear shriveled or damaged. For best results, use seeds from the most recent growing season to ensure a high germination rate.

Select a healthy parent plant and cut a 4-6 inch segment of stem. Ensure the cutting is taken just below a node, and remove the leaves from the lower half to prevent rotting when planted.

For division propagation, gently dig up the plant and shake off excess soil. Carefully separate the root ball into sections, ensuring each has roots attached. Replant the divisions promptly into prepared soil.

More About Propagating Techniques→

How to Repot Starry rosinweed plant?

Repotting frequency: Every 2-3 years

Look for signs such as roots emerging from drainage holes or stunted growth indicating the plant is root-bound. Spring or summer is ideal as the plant is in active growth, making it resilient to the stress of repotting.

Select a pot that is 1-2 inches larger in diameter than the current one, with ample drainage holes. This size ensures enough space for growth without overwhelming the plant, preventing root rot and ensuring better nutrient absorption.

Opt for a sandy loam soil that offers excellent drainage while retaining enough moisture to nourish the plant. A balanced mix prevents waterlogging and supports sustained growth, mimicking natural conditions.