Overview
Cotula thunbergii Harv. is a small, perennial plant that belongs to the Asteraceae family. This plant is native to South Africa, particularly in the Eastern Cape Province.
Common Names
Cotula thunbergii Harv. is commonly known as the "Cape chamomile" or the "stinking chamomile".
Appearance
The Cape chamomile is a low-growing, mat-forming plant that typically grows up to 6-8 inches in height. It has grayish-green, finely-divided leaves that are aromatic and covered with fine hairs. The stems are reddish in color and prostrate, spreading out along the ground.
The plant produces yellow, daisy-like flowers that are 1 inch in diameter with cone-shaped centers. The flowers bloom in late spring and summer and are strongly aromatic but have a pungent smell that some people consider unpleasant.
Uses
The Cape chamomile plant is commonly used in traditional medicine as an herbal remedy for various ailments. The plant contains essential oils that have antiseptic, anti-inflammatory, and analgesic properties.
The Cape chamomile's flowers have also been used to make tea or potpourri. In addition, the plant is also used as an aromatic and ornamental plant in gardens, rockeries, and as a ground cover in sunny areas.
Despite its unpleasant odor, the Cape chamomile is an attractive and useful plant that can serve a variety of purposes.
Light Requirements
The Cotula thunbergii Harv. thrives best in partially shaded areas with bright indirect light. However, they can still survive in full sun with proper moisture. Too much light can scorch the leaves and cause them to wilt.
Temperature Requirements
The plant prefers mild temperatures between 60°F to 75°F (15.5°C to 24°C). It is frost tender, so it needs to be kept indoors or moved to a warmer area during the cold months. The plant will show signs of stress if the temperature drops below 50°F or goes above 85°F.
Soil Requirements
The Cotula thunbergii Harv. needs well-draining soil that is moist but never waterlogged. The plant performs best in slightly acidic to neutral soil with a pH range of 5.5 to 7.0. It is important to add sufficient organic matter to the soil, such as compost or peat moss, to maintain moisture. Regular fertilization during the growing season can also ensure good plant health.
Cultivation methods
Cotula thunbergii Harv. is a perennial plant that is best grown in warm and dry climates. The plant loves full sun and well-draining soil. It can tolerate light shade, but too much shade can inhibit growth and flowering.
Propagation can be done from seed or by dividing existing plants. Seeds can be sown indoors in the spring and transplanted outside once the seedlings are well-established. Division can be done in the early spring or fall when the plant is dormant.
Watering needs
When it comes to watering Cotula thunbergii Harv., it is important to allow the soil to partially dry out between watering. Too much water can lead to root rot and other problems. The plant can tolerate short periods of drought, but extended periods without water can cause the plant to wilt and ultimately lead to its demise. Watering should be done in the early morning or late afternoon to avoid evaporation and to prevent water from sitting on the leaves in the heat of the day.
Fertilization
Like most plants, Cotula thunbergii Harv. benefits from regular fertilization. The plant prefers a balanced fertilizer that is higher in phosphorus than nitrogen. Fertilization should be done in the early spring and again in the early fall. Avoid using too much fertilizer as this can lead to excessive growth and weak stems.
Pruning
Pruning is not essential for Cotula thunbergii Harv. However, if the plant becomes leggy or overgrown, pruning can be done in the early spring. Cut back the stems to encourage new growth and a bushier plant. Deadheading can also be done to prolong the flowering period. Simply snap off the spent flowers as they appear.
Propagation Methods for Cotula thunbergii Harv.
Cotula thunbergii Harv., commonly known as Thunberg’s cotula, is a mat-forming perennial plant that originates from South Africa. It is a popular plant for ground cover because of its ability to grow quickly and fill in empty spaces. Cotula thunbergii Harv. can be propagated in several ways, including:
Seed Propagation
The easiest and most common way to propagate Cotula thunbergii Harv. is by seed. Seeds can be sown during the spring and summer, either indoors or directly into the ground. The ideal temperature for germination ranges from 15-20°C. The seeds should be covered lightly with soil, and should be watered consistently but not excessively until the seedlings emerge.
Division Propagation
Division propagation is also possible for Cotula thunbergii Harv. This method involves separating the plant into smaller sections, each with their own root system and shoots. It is best to do this during the spring growing season when the plant is actively growing. The root systems of the smaller sections should be kept moist while the new plants establish themselves.
Cutting Propagation
Cuttings are another option for propagating Cotula thunbergii Harv. This method works best during the early summer when the plant is in its active growth phase. Cuttings should be taken from the newer stems, just below a leaf joint, around 10cm long. The basal leaves should be removed and the remaining leaves should be trimmed back by half. The cuttings should be dipped in rooting hormone and inserted into a potting mix made up of two parts perlite and one part peat moss. The potting mix should be kept moist and humid until the cuttings have rooted.
Regardless of the propagation method used, Cotula thunbergii Harv. requires consistent moisture and well-draining soil to establish successfully. With proper care, this plant can quickly establish into an attractive ground cover.
Disease and Pest Management for Cotula thunbergii Harv.
Cotula thunbergii Harv. is an attractive plant species known for its small, flat, silver-gray leaves and yellow button-like flowers. However, like all other plants, it is prone to diseases and pests. Here are some common issues that you might face with Cotula thunbergii Harv. and how to manage them:
Diseases
Leaf spots: Cotula thunbergii Harv. is susceptible to leaf spot diseases, caused by fungal pathogens such as Cercospora cotulae and Phoma exigua. Symptoms include brown or black spots on the leaves, which may enlarge and coalesce, causing leaf drop and reduced vigor. The best way to prevent leaf spots is to keep the plant foliage dry by avoiding overhead watering. If you notice leaf spots, promptly remove the infected leaves and dispose of them in the trash, not compost.
Root rot: Cotula thunbergii Harv. may suffer from root rot, caused by soil-borne fungi such as Phytophthora and Pythium. Symptoms include wilting, yellowing, and stunted growth, which may progress to plant death. The best way to prevent root rot is to ensure well-draining soil, avoid overwatering, and practice proper sanitation. If you suspect root rot, carefully remove the plant from the soil, trim off any mushy or black roots, and repot the plant in new, sterile soil.
Pests
Aphids: Cotula thunbergii Harv. is susceptible to aphid infestations. Symptoms include curled and distorted leaves, sticky honeydew, and sooty mold. The best way to prevent aphids is to keep the plant healthy and strong, which can resist infestations. You can also use insecticidal soap or neem oil as a natural remedy. Spray them directly on the aphids and repeat the application as needed, following the manufacturer's instructions.
Spider mites: Cotula thunbergii Harv. is vulnerable to spider mites, tiny arachnids that suck the plant sap, causing yellow and bronzed leaves. The best way to prevent spider mites is to increase humidity and keep the plant foliage dust-free. You can also use insecticidal soap or neem oil to control the infestation. Spray them directly on the spider mites and repeat the application as needed, following the manufacturer's instructions.
Cotula thunbergii Harv. is a lovely plant that can adorn your garden or indoor space. With appropriate disease and pest management, you can ensure its beauty and health for years to come.
