Overview
Cotula radicalis (Killick & C.Claassen) Hilliard & B.L.Burtt is a species of flowering plant in the family Asteraceae. It is commonly known as buttonweed or button cotula and is native to Southern Africa.
Appearance
The buttonweed plant has low-growing, spreading stems and tiny button-like yellow flowers. It has finely-divided, airy leaves that are an attractive blue-gray color. The plant typically grows to a height of 2-5cm, with a spread of up to 30cm. It is a perennial succulent, with roots that can extend up to 30cm deep in the soil.
Uses
Cotula radicalis is a versatile and hardy plant that is often used in rock gardens, as a ground cover or as a container plant. It is also popular for 'green roofing' systems, as it is tolerant of dry and windy conditions. The plant can be propagated easily through cuttings, and they can also be grown from seed, although the germination rate can be quite low. The plant is generally pest and disease-free, making it a low maintenance choice for gardeners.
The plant is also used in traditional medicine in some parts of southern Africa. The leaves and stems are dried and made into a tea that is said to have anti-inflammatory and diuretic properties. The plant is also used to treat a variety of ailments including respiratory and digestive issues, skin conditions, and arthritis. However, caution should be exercised when using it for medicinal purposes, as there is currently limited scientific evidence to support its effectiveness.
Light Requirements
Cotula radicalis requires full sun to partial shade in order to properly grow. While this plant can tolerate some shade, it is best to keep it in a sunny location as it tends to bloom more profusely. This species of Cotula will not thrive indoors or in areas with low light levels.
Temperature Requirements
This plant is native to Southern Africa and can tolerate a wide range of temperatures. Cotula radicalis is a hardy plant, and is able to survive temperatures as low as 20°F (-6°C) if given adequate protection. It can also withstand high temperatures up to 100°F (38°C) in hot, dry environments. However, the optimal temperature range for growth is generally between 60-85°F (15-29°C).
Soil Requirements
Cotula radicalis prefers well-drained soil with a neutral pH level (6-7). The soil should be loose and friable, and have good water retention capacity. This plant is adapted to poor soils and can thrive in rocky, sandy or clay soils. However, it is important to avoid waterlogged soils as this can lead to root rot. Additionally, regular fertilization and amending the soil with organic matter can help improve growth and overall health of the plant.
Cultivation Methods
Cotula radicalis is a hardy, low-maintenance plant that can thrive in a wide range of soil and climate conditions. It is best grown in well-draining soil that is rich in organic matter, and prefers full sun to light shade. The plant can be propagated by seeds or cuttings, and is ideally planted in spring or autumn.
Watering Needs
Watering needs for Cotula radicalis are low to moderate. It is important to allow the soil to dry out between waterings to prevent waterlogging, which can cause root rot. During periods of extended drought, the plant may require more frequent watering to maintain its health and vigor.
Fertilization
Cotula radicalis does not require a lot of fertilizer to thrive. A balanced, slow-release fertilizer can be applied once or twice a year during the growing season to provide the plant with essential nutrients. Avoid over-fertilizing, as this can lead to excessive vegetative growth and reduced flowering.
Pruning
Pruning of Cotula radicalis is not usually necessary, as the plant typically maintains a compact, mounding growth habit. However, if growth becomes too dense or leggy, the plant can be lightly pruned in the spring to promote new growth and maintain its shape. Deadheading spent flowers can also encourage more blooms to develop.
Propagation of Cotula radicalis
Cotula radicalis (Killick & C.Claassen) Hilliard & B.L.Burtt, commonly known as Cape buttons, produce tiny flowers that resemble colorful buttons and has a thin trunk that grows up to 12cm high. It is an ideal plant for rock gardens and as a ground cover. Propagation of Cotula radicalis can be done through seeds, stem cuttings, and division, and they all have their specific requirements.
Propagation through seeds
The best time to propagate Cotula radicalis through seeds is during the spring when the temperatures are between 18-21°C. The seeds should be scattered on the soil surface and then lightly pressed to make contact with the soil. They should also be covered with a light layer of soil. The soil should be kept consistently moist, not waterlogged, and should be exposed to sun or partial shade in a greenhouse or outside. The seeds will germinate after two to four weeks.
Propagation through stem cuttings
Propagation of Cotula radicalis through stem cutting is best done in summer or early autumn when the plant is actively growing. They should be cut at a length of 5-7cm and should be dipped in rooting hormone before planting. The cuttings should then be planted in a mixture of sand and peat moss. The plant will require high humidity, and a spray bottle can be used to maintain the desired level of moisture. The cutting should root within six to eight weeks.
Propagation through division
Cotula radicalis can also be propagated through division. This method is best done during spring or early autumn when the plant is actively growing. The plant should be lifted out of the soil, and the roots should be gently separated. Each division should have at least one shoot and a clump of roots. The divisions should then be replanted in suitable soils and watered thoroughly. It is essential to ensure that the soil is consistently moist and that the plant is placed in partial shade until new growth emerges.
By following these propagation methods, Cotula radicalis can be easily propagated and used to add a burst of color to rock gardens and ground covers.
Disease Management
Cotula radicalis is generally a hardy plant and is not often affected by diseases. However, here are some common diseases that may affect the plant and ways to manage them:
- Root Rot: Root rot can be caused by overwatering or poorly draining soil. To manage root rot, reduce watering and improve soil drainage. If the disease has progressed, it may be necessary to remove the affected plant and soil before replanting in fresh soil.
- Powdery Mildew: Powdery mildew can occur due to high humidity and poor air circulation. To manage powdery mildew, prune affected leaves or stems, increase air circulation around the plant, and avoid overhead watering. Fungal sprays may also be used as a preventative measure.
Pest Management
Cotula radicalis is also generally not susceptible to pests, but here are some common pests that may affect the plant and ways to manage them:
- Whiteflies: Whiteflies are small, winged insects that feed on leaves causing damage and wilting. To manage whiteflies, use insecticidal soap or neem oil to kill them on contact. Regularly monitor plants for any signs of infestation.
- Snails and slugs: Snails and slugs can feed on the leaves and flowers of the plant. To manage these pests, manually remove them if you spot them around the plants. You may also use bait or traps to attract them away from the plants.
Regularly monitoring the plant and maintaining good cultural practices can help prevent both destructive diseases and pests. This includes watering the plant correctly, ensuring proper sunlight exposure, and fertilizing appropriately. Maintaining a healthy plant ensures that it is less susceptible to any potential disease or pest damage.
