Origin
Silphium terebinthinaceum Ell., non Jacq., commonly known as Prairie Dock, is a native plant to the central and eastern regions of the United States. It can be found growing in prairies, fields, and waste areas throughout the Midwest and the Great Plains.
Common Names
Prairie Dock is also known by a variety of other names, including Indian Cup, Rosinweed, and Gum Plant. The name Gum Plant comes from the plant's resinous sap, which has been used in medicinal and industrial applications.
Uses
Prairie Dock has a long history of use by Native Americans and early settlers in the United States. The plant's roots were often used as a traditional remedy for coughs, fevers, and other respiratory ailments. The resinous sap was also used to make glue, varnish, and pitch for boats.
Today, Prairie Dock is valued for its ornamental qualities. The plant's large leaves and tall, sturdy stems make it a popular choice for landscaping and garden design. It is also an important food source for bees and other pollinators.
General Appearance
Prairie Dock is a large, herbaceous plant that can grow up to 10 feet tall. It has a deep taproot that allows it to survive in harsh, dry conditions. The plant produces large, serrated leaves that can be up to two feet long and six inches wide. The leaves are green and slightly fuzzy to the touch. In mid to late summer, Prairie Dock produces tall, branching stems topped with clusters of yellow flowers. The flowers attract a variety of pollinators, including butterflies and bees.
Light Requirements
Silphium terebinthinaceum Ell., non Jacq., prefers full sun to partial shade. It can tolerate shade, but it may result in reduced growth and flowering.
Temperature Requirements
This plant is hardy to USDA zones 5 to 9, which means it can thrive in temperatures ranging from -20°F to 30°F. Silphium terebinthinaceum Ell., non Jacq. prefers a moderately warm climate and does not like extreme heat or cold temperatures. The optimal temperature for its growth and development ranges from 68°F to 86°F.
Soil Requirements
The plant prefers well-drained, fertile soils with a slightly acidic pH ranging from 6.0 to 7.5. Silphium terebinthinaceum Ell., non Jacq. is tolerant of different soil types, including loam, clay, and sandy soils. The addition of organic matter to the soil can improve soil fertility and promote healthy growth.
Cultivation of Silphium terebinthinaceum Ell.
The Silphium terebinthinaceum Ell. plant is commonly known as Prairie Dock, making it an excellent addition to prairie gardens or mixed borders. Growing to a height of up to 12 feet, it is a widely popular plant among gardeners, thanks to its stunning yellow flowers.
Being native to North America, the Prairie Dock plant prefers full sun conditions and well-draining soil. It grows well in USDA hardiness zones three to nine and can survive in both dry and moist soils.
For best results, sow the seeds of Prairie Dock plant in the fall or early spring. You can also propagate the plant by dividing its roots from early spring to mid-spring.
Watering needs of Silphium terebinthinaceum Ell.
The Prairie Dock plant is drought-tolerant once it's fully established. However, it would be best to water the plant regularly, especially during its first growing season. Provide enough water to keep its soil consistently moist but not waterlogged
During the dry season, you may have to increase the frequency of watering to keep the soil damp. Avoid overwatering Prairie Dock plant, as it's susceptible to root rot.
Fertilization of Silphium terebinthinaceum Ell.
While the Prairie Dock plant can survive without fertilizer, it benefits from a well-balanced fertilizer applied in early spring. Apply a slow-release, granular fertilizer that's low in nitrogen to the plant's soil. A balanced fertilizer mix with an N-P-K ratio of 10-10-10 would be ideal for this plant.
You can also mulch around the base of the plant with compost or well-aged manure. The Prairie Dock plant's roots will absorb the nutrients slowly, keeping the plant healthy throughout the growing season.
Pruning of Silphium terebinthinaceum Ell.
The Prairie Dock plant doesn't require much pruning, but it helps to cut it back by a third in late spring or early summer. This pruning helps the plant to remain bushy and stimulate blooming.
You can also deadhead the spent flowers to encourage the plant to produce more flowers and increase the overall appearance of the plant. Cut back any damaged or yellowing foliage to keep the plant looking healthy and attractive.
Propagation of Silphium terebinthinaceum Ell., non Jacq.
Silphium terebinthinaceum, commonly known as Prairie Dock, is a tall perennial herb that is native to the central and eastern regions of the United States. Propagating this plant can be done by several methods such as seed, division, and cuttings.
Seed Propagation
Seed propagation is one of the easiest and most common methods used for propagating Silphium terebinthinaceum. Seeds should be collected from the plant after they have matured, which is usually in the fall season. The seeds must be sown immediately or stored in a cool and dry place until the spring season arrives.
Before planting the seeds, the soil must be prepared by removing any debris and adding organic matter. The seeds should be planted one inch deep into the soil and spaced about 12-18 inches apart. Water the seeds regularly and maintain a consistent moisture level until they germinate. Germination usually occurs within 2-3 weeks of planting the seeds.
Division Propagation
Division propagation is another method used for propagating Silphium terebinthinaceum. The best time for dividing the plant is in the spring season, just as new growth begins.
To divide the plant, the clump should be dug up carefully, and the roots should be separated into several sections. Each section should have a good root system and several shoots. These sections can then be replanted and watered regularly to maintain the moisture level.
Cutting Propagation
Cutting propagation is a method suitable for propagating Silphium terebinthinaceum that produces identical plants to the parent plant. Dynamic stem cuttings must be harvested in the spring season when the plant is about 12 inches tall.
The cutting should be approximately 6 inches long, with a minimum of two sets of leaves. The lower leaves are then removed, and the cutting is dipped into a rooting hormone before being planted in a well-draining soil mix. The cutting should be watered regularly until roots develop, which usually takes about two to four weeks. After the roots have developed, the cutting can be transplanted to the garden bed.
Disease Management
Silphium terebinthinaceum is generally resistant to most pests and diseases but can be susceptible to some. Here are some common diseases and ways to manage them:
Rust
Rust is a fungal disease that causes reddish or orange spots on leaves. It can be controlled by removing the infected plant parts and destroying them. Fungicides can be used to prevent the disease from spreading.
Leaf Spot
Leaf spot is a fungal disease that causes brown or black spots on leaves. It can be controlled by removing the infected plant parts and destroying them. Fungicides can be used to prevent the disease from spreading.
Powdery Mildew
Powdery mildew is a fungal disease that causes a white powdery coating on leaves. It can be controlled by removing the infected plant parts and destroying them. Fungicides can be used to prevent the disease from spreading.
Pest Management
Here are some common pests that might affect Silphium terebinthinaceum and ways to manage them:
Aphids
Aphids are small insects that suck the sap from leaves and stems. They can be controlled by spraying the plant with a strong jet of water or by applying insecticidal soap.
Spider Mites
Spider mites are tiny insects that spin webs on the plant. They can be controlled by spraying the plant with a strong jet of water or by applying insecticidal soap.
Caterpillars
Caterpillars are the larvae of moths and butterflies and can eat through the leaves of Silphium terebinthinaceum. They can be controlled by picking them off the plant by hand or by applying Bacillus thuringiensis (Bt), a naturally occurring bacteria that is lethal to caterpillars.
