Overview
Humularia descampsii var. acuta P.A.Duvign. is a herbaceous plant belonging to the family Asteraceae.
Origin
The plant is native to Central Africa, where it is commonly found in Congo, Rwanda, and Burundi.
Common Names
The plant is commonly known as "Kakkerlak-bossie" or "Cockroach bush" due to its unpleasant odor, which is similar to that of a cockroach.
Appearance
The plant is a perennial herb that grows up to 30 cm tall. It has a slender, hairy stem and a rosette of leaves at its base. The leaves are narrow and lance-shaped, measuring up to 8 cm long by 2 cm wide. The flowers are small and white, arranged in clusters at the tips of the branches. The plant has an unpleasant smell due to the presence of essential oils.
Uses
The plant has several traditional medicinal uses in Africa. It is used to treat digestive disorders, such as diarrhea and stomach ulcers, and respiratory problems like asthma and bronchitis. The plant is also used as an insect repellent due to its strong odor.
However, due to its strong odor, the plant is not commonly cultivated for ornamental use.
Light Conditions
Humularia descampsii var. acuta requires moderate to bright light conditions for optimal growth. It can tolerate partial shade but excessive shade can lead to leggy growth and reduced flowering. Direct sunlight should be avoided as it can cause foliage burn.
Temperature Requirements
Humularia descampsii var. acuta grows well in moderate temperatures ranging from 18°C to 25°C. It can also tolerate slightly cooler temperatures but frost should be avoided at all costs. Temperature fluctuations should also be avoided as they can damage the plant and stunt its growth.
Soil Requirements
Humularia descampsii var. acuta thrives in well-draining soil that is rich in organic matter. A pH level ranging from slightly acidic to neutral (pH 5.5-7.5) is ideal for optimal growth. The soil should be kept moist but not waterlogged as this can cause root rot and other fungal diseases. A layer of mulch can be added to help retain soil moisture levels.
Cultivation Methods
Humularia descampsii var. acuta is an easy-to-care-for plant, making it ideal for novice gardeners. This variety prefers well-drained and slightly acidic soil with a pH level between 5.5 and 6.5.
It can be grown outdoors in cool to mild climates, but it thrives particularly well indoors in pots where humidity levels can be easily regulated, and temperatures can be kept constant.
The plant needs moderate to bright light but should not receive direct sunlight. It should also be kept away from strong winds and drafts that could damage its delicate leaves.
Watering Needs
The Humularia descampsii var. acuta plant requires moderate watering. Overwatering can lead to root rot and fungal diseases that could kill the plant. Allow the soil to dry out between watering sessions, and make sure the soil doesn't become too wet, especially during the winter period when the plant is dormant.
It is important to use room temperature tap water or rainwater to avoid temperature shocks and prevent the accumulation of salts that could harm the plant.
Fertilization
The plant requires a balanced fertilizer with an NPK ratio of 10-10-10. It should only be fertilized during its growing season, which is spring to summer, and should be done every two weeks.
Overfertilization can cause the buildup of salts in the soil, leading to root burn and plant damage; therefore, it is essential to follow the manufacturer's instructions on the fertilizer packaging and reducing the dosage if necessary.
Pruning
Pruning is not required for this variety, but it can help maintain its shape and prevent the plant from becoming too leggy or lopsided. If pruning is necessary, it should be done sparingly and only during its growing season.
A good rule of thumb is to prune no more than one-third of the plant's length or foliage. This allows the plant to recover properly and minimizes the risk of damage or stress.
Propagation of Humularia descampsii var. acuta
Humularia descampsii var. acuta can be propagated using various methods, including:
1. Seed propagation
Seeds of Humularia descampsii var. acuta are available from various seed suppliers. Sow seeds in a well-draining potting mix, and keep moist until germination, which can take up to six months. Once seedlings are large enough, they can be transplanted into individual pots.
2. Stem cuttings propagation
Stem cuttings are the most common method of propagating Humularia descampsii var. acuta. Take a 3-4 inch cutting from the parent plant, ensuring it has at least two nodes. Remove the lower leaves, and dip the cut end into rooting hormone. Plant the cutting in a well-draining potting mix and keep it moist until roots develop, which can take around four weeks.
3. Division
Humularia descampsii var. acuta can also be propagated by division. Gently remove the plant from its pot and gently separate the root ball into two or more sections. Ensure each section has healthy roots and replant in fresh potting mix.
Disease Management
The plant Humularia descampsii var. acuta can be susceptible to certain diseases, which can lead to stunted growth, yellowing of leaves, and even death. Some of the common diseases that might affect the plant include:
- Leaf spot: This disease appears as brown spots on the leaves and can cause them to drop prematurely. It is caused by a fungal infection, and can be managed by removing any infected leaves and applying a fungicide.
- Powdery mildew: This disease appears as a white powder on the leaves and can cause them to become distorted. It is also caused by a fungal infection and can be managed by removing infected leaves and keeping the plant well-ventilated and dry.
- Root rot: This is a common problem in plants, especially those that are over-watered. It can cause the roots to become mushy and can lead to wilting and death of the plant. To manage root rot, it is important to ensure that the plant is not over-watered and there is good drainage.
Pest Management
Humularia descampsii var. acuta can also be affected by certain pests, such as:
- Spider mites: These tiny pests can be hard to spot, but they can cause leaves to become discolored and can lead to webbing on the plant. They can be managed by using insecticidal soap or neem oil.
- Mealybugs: These pests appear as small white fuzzy patches on the leaves and stems. They can be managed by using a cotton swab dipped in rubbing alcohol to remove them, or by using insecticidal soap.
- Aphids: These pests can be found on the undersides of leaves and can cause distortion and yellowing of the leaves. They can be managed by using insecticidal soap or neem oil.
To prevent further infestations and diseases, it is important to keep the plant well-maintained, regularly remove dead or infected leaves, and monitor for any signs of pest or disease problems. Proper watering and fertilization will also help keep the plant healthy and less susceptible to these problems.
