Origin and Common Names
Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm. is a herbaceous perennial plant that belongs to the Asteraceae family. It is commonly known as Rock Tickseed or Large-flowered Tickseed. This plant is native to North America and is found in many parts of the United States, including Texas, Oklahoma, and Missouri.
General Appearance
The plant has a compact habit, growing up to 2 feet in height and spreading up to 3 feet in width. The leaves of this plant are lance-shaped, dark green in color, and grow up to 4 inches long. The flowers of the plant are large, showy, and bright yellow in color, with a diameter of up to 2 inches. The flowers bloom from late spring to early fall, attracting bees and butterflies with their nectar. The plant has a long and deep taproot that helps it withstand dry and drought conditions.
Uses
The Rock Tickseed is a popular garden plant due to its bright flowers and drought tolerance. It is often used as a groundcover or border plant in gardens and landscapes. The plant is also used in natural landscaping, prairie restorations, and erosion control. Additionally, the flowers of the plant are cut for floral arrangements and can be used in dried flower arrangements.
Medicinally, the leaves of the plant were used by Native American tribes to treat various ailments, including fever, stomachache, and headache. However, little research has been done on the medicinal properties of the plant.
Growth Conditions for Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm.
Light: Coreopsis grandiflora Hogg ex Sweet var. saxicola is a sun-loving plant and requires full sun exposure for at least six hours a day to thrive. It cannot tolerate shade or partial shade and may become weak and susceptible to diseases if grown in such conditions.
Temperature: The plant is adapted to grow in a range of temperatures but prefers warm to hot environments. It can withstand temperatures as low as -28.8°C and as high as 35°C but grows best when the temperature is between 18°C and 27°C.
Soil: The soil for Coreopsis grandiflora Hogg ex Sweet var. saxicola should be well-draining, rich in organic matter, and slightly acidic. It can adapt to a range of soil types including sandy, loamy, and clayey soils but does not tolerate water-logged soils or soils that are too dry. The ideal pH range is between 6.0 and 6.5.
Moisture: The plant requires moderate moisture levels to grow well but is drought-tolerant once established. Watering should be done whenever the topsoil feels dry. Overwatering should be avoided as it can lead to root rot and other fungal diseases.
Fertilizer: Fertilization is not necessary for Coreopsis grandiflora Hogg ex Sweet var. saxicola but it can benefit from a balanced fertilizer application during the growing season. Fertilization should be done sparingly and according to the manufacturer's instructions.
Propagation: The plant can be propagated through seeds or division. Seeds should be sown in spring or fall while division should be done in spring or early fall. Propagation through cuttings is not recommended as it is difficult to root and establish.
Cultivation of Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm.
Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm. grows well in full sunlight, but it can also tolerate partial shade. Choose a location with well-drained soil that is rich in organic matter. This plant is ideal for growing in rock gardens, borders, and containers.
The seeds can be sown directly in the planting site after the last frost date or indoors six to eight weeks before planting out. The seeds should be lightly covered with soil and kept moist to germinate in a week.
Watering Needs of Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm.
Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm. is a drought-tolerant plant that is moderately watered. During the first year, water regularly to keep the soil moist but not waterlogged. After that, the plant can survive on natural rainfall.
It is best to water in the morning to avoid wetting the foliage at night. Water the soil rather than the foliage to prevent the plant from developing fungal diseases.
Fertilization of Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm.
Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm. does not require too much fertilization. Too much fertilizer can cause the plant to produce lush foliage instead of flowers.
Apply a balanced, slow-release organic fertilizer like 10-10-10 in early spring and water thoroughly after application. Another alternative is to add compost to the planting site before the start of the growing season.
Pruning of Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm.
Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm. requires minimal pruning, but it is important to deadhead spent flowers to encourage repeat blooming.
Remove the faded flowers by cutting the stem at the base of the flower head. This practice will preserve the plant's energy for producing more flowers and prevent the plant from going to seed.
Propagation of Coreopsis grandiflora Hogg ex Sweet var. saxicola (Alexander) E.B. Sm.
There are primarily two propagation methods to grow Coreopsis grandiflora - through seeds and stem cuttings.
Propagation through Seeds
The seeds of Coreopsis grandiflora are readily available in nurseries and can also be collected from mature plants. Seeds should be sown in well-draining soil during spring or summer.
Before sowing, the seeds can be scarified (scratched or rubbed) with sandpaper or soaked in water for a few hours to enhance germination.
The seeds should be sown on moist soil and placed in a warm, bright location. Once the seedlings have grown to a suitable size, they can be transplanted into individual pots or in the garden beds.
Propagation through Stem Cuttings
Coreopsis grandiflora can also be propagated through stem cuttings. This method is usually preferred over seeds as it is faster and ensures that the new plant is identical to the parent plant.
The stem cuttings should be taken in late spring or early summer. The cuttings should be around 4 to 6 inches long and should be taken from healthy, disease-free plants.
The lower leaves should be removed, and the stem cutting should be planted in moist, well-draining soil. The pot should be kept in a bright, shady location until new growth appears. Once new growth appears, the new plant can be transplanted into individual pots or in the garden beds.
Regardless of the propagation method used, newly propagated Coreopsis grandiflora plants need to be well-watered and kept in a bright, sunny spot until they start growing vigorously.
Disease Management
Coreopsis grandiflora Hogg ex Sweet var. saxicola is a relatively low-maintenance plant that is not susceptible to many diseases. However, it is important to keep an eye out for any signs of disease to ensure that the plant remains healthy and strong.
One common disease that may affect this plant is powdery mildew. This disease is characterized by a white, powdery substance that appears on the leaves, stems, and flowers. To manage powdery mildew, it is recommended to remove any infected plant parts, improve air circulation around the plant, and ensure that the plant is not stressed by factors such as drought or nutrient deficiency. Neem oil and other fungicides may also be used as a treatment.
Another potential disease that may affect Coreopsis grandiflora Hogg ex Sweet var. saxicola is leaf spot. Leaf spot is characterized by dark spots on the leaves, which can eventually lead to defoliation. To manage leaf spot, it is recommended to remove any infected plant parts and avoid wetting the leaves when watering. Fungicides may also be used as a treatment.
Pest Management
Coreopsis grandiflora Hogg ex Sweet var. saxicola is also generally not prone to serious pest problems. However, there are a few common pests that may affect the plant.
One such pest is aphids. Aphids are small insects that suck the sap from leaves and stems, causing stunted growth, distorted leaves, and weak plants. To manage aphids, it is recommended to spray the plant with a strong jet of water to knock them off the plant, or to use insecticidal soap or neem oil as a treatment.
Another pest that may affect this plant is spider mites. Spider mites are tiny arachnids that can cause yellowing and stippling on the leaves, as well as premature leaf drop. To manage spider mites, it is recommended to remove any heavily infested plant parts and to improve the humidity around the plant. Insecticidal soaps and neem oil may also be used as a treatment.
Overall, by keeping an eye out for signs of disease or pest problems, regularly inspecting the plant, and promptly addressing any issues that arise, it is possible to keep Coreopsis grandiflora Hogg ex Sweet var. saxicola healthy and strong.
