Origin:
Argyrolobium rupestre (E.Mey.) Walp. subsp. kilimandscharicum (Taub.) Polhill, commonly known as Kilimanjaro bush bean, is a plant species native to the Eastern African region. It is predominantly found in Tanzania, Kenya, and Uganda, occupying rocky and dry habitats such as hills and mountains.
Common Names:
In addition to Kilimanjaro bush bean, Argyrolobium rupestre (E.Mey.) Walp. subsp. kilimandscharicum (Taub.) Polhill is also referred to as African silver-leafed bean and Kilimanjaro pea in different parts of its range.
Uses:
Argyrolobium rupestre (E.Mey.) Walp. subsp. kilimandscharicum (Taub.) Polhill has been traditionally used in East African society for various purposes. The seeds are a good source of protein and have been consumed as food by some indigenous populations. The plant's roots have been used as medicine to treat respiratory infections such as pneumonia, asthma, and bronchitis. In some communities, they believe in the plant's supernatural abilities to ward off evil spirits. Currently, the Kilimanjaro bush bean's potential as a livestock feed and for soil conservation initiatives by nitrogen fixation is under scrutiny.
General Appearance:
The Argyrolobium rupestre (E.Mey.) Walp. subsp. kilimandscharicum (Taub.) Polhill is a small, annual herb that grows to approximately 30-60cm in height. It is characterized by a deep taproot and angular stems that are covered with silver-grey hairs. The leaves are compound, consisting of three leaflets, with a silver sheen on the underside, giving them a distinctive appearance. The flowers are small and have a yellow or orange color. They are arranged in loose clusters that extend from a single stalk and bloom from July to November. The plant produces small, flattened pods that contain small, dark-colored seeds.
Light Requirements
Argyrolobium rupestre subsp. kilimandscharicum requires full sun exposure to thrive. It is not suitable for shady areas or indoor planting. The plant's growth and blooming are directly correlated with the amount of sunlight it receives. Therefore, planting it in an area that receives at least six hours of direct sunlight is essential.
Temperature Requirements
The subsp. kilimandscharicum grows best in a tropical or subtropical climate. The plant can withstand moderate temperatures ranging from 15oC to 30oC. However, it requires cooler temperatures (around 10oC) during its dormancy period. Nighttime temperatures should not be too high as this may affect the plant's respiration rate.
Soil Requirements
The Argyrolobium rupestre subsp. kilimandscharicum requires well-drained soils with a pH of 6.0 to 7.5. The soil type must be sandy loam with a high level of organic matter. The plant prefers dry (well-drained) soils over those that are over-saturated with water. Although the plant is native to mountainous regions, it can grow in sandy soils with adequate nutrients.
Cultivation Methods
Argyrolobium rupestre (E.Mey.) Walp. subsp. kilimandscharicum (Taub.) Polhill is a perennial shrub that is native to Tanzania and Kenya. It is best grown in well-drained soils that are acidic and have good drainage. The plant prefers full sunlight and is drought-tolerant, making it ideal for xeriscaping gardens.
Watering Needs
Although drought-tolerant, Argyrolobium rupestre (E.Mey.) Walp. subsp. kilimandscharicum (Taub.) Polhill requires regular watering to establish deep roots. It is essential to irrigate the plant frequently during the first growing season to enable the roots to penetrate deeper into the soil. Once established, the plant can thrive with minimal watering. Depending on the local climate conditions, it is advisable to water the plant once a week during the growing season.
Fertilization
Argyrolobium rupestre (E.Mey.) Walp. subsp. kilimandscharicum (Taub.) Polhill is a resilient plant that does not require frequent fertilization. However, it is advisable to add organic matter to the soil, such as well-rotted compost or manure, in the spring to enhance soil fertility. Avoid using synthetic fertilizers, which can cause damage to the roots.
Pruning
Argyrolobium rupestre (E.Mey.) Walp. subsp. kilimandscharicum (Taub.) Polhill requires minimal pruning. However, it is advisable to remove any dead or damaged stems in the early spring to promote healthy growth. Avoid pruning the plant heavily, which can reduce blooming and cause damage to the plant. Pruning should be done regularly to keep the plant in shape and avoid overcrowding.
Propagation of Argyrolobium rupestre subsp. kilimandscharicum
The Argyrolobium rupestre subsp. kilimandscharicum plant can be propagated by both seed and cutting methods.
Propagation by seeds
The seeds of Argyrolobium rupestre subsp. kilimandscharicum should be sown during the spring season. The seeds should be sown in soil mixed with sand and kept moist in a warm and sunny location.
After the seeds have been sown, they should be covered lightly with soil, and the soil should be kept moist at all times. Germination may take up to 14 days. Once the seedlings are at least 2 inches tall, they can be transplanted into individual pots.
Propagation by cuttings
Argyrolobium rupestre subsp. kilimandscharicum can be propagated by cuttings taken during the spring season. Cuttings should be taken from the stem tips, and they should be at least 4 inches long.
The cutting should be stripped of all but a few leaves at the top. Dip the cut end of the cutting into rooting hormone powder. Plant the cuttings in pots filled with a mixture of sand and soil. Cover the pots with a plastic bag to keep the humidity level high and place them in a warm and sunny location.
The cuttings should develop roots within 4 to 6 weeks. Once the cuttings have developed roots, they can be transplanted into individual pots.
Disease and Pest Management for Argyrolobium rupestre subsp. kilimandscharicum
Argyrolobium rupestre subsp. kilimandscharicum, also known as the Kilimanjaro bush pea, is a hardy shrub that is native to East Africa. Although it is relatively disease and pest resistant, it can still be affected by a few common problems. Here are some ways to manage diseases and pests that might affect the plant:
Common Diseases
Fungal diseases: One of the most common fungal diseases that can affect Argyrolobium rupestre subsp. kilimandscharicum is powdery mildew. This disease usually manifests as a white, powdery coating on the leaves and stems of the plant. To manage this disease, you can use a fungicide spray. Alternatively, you can prune any affected foliage and improve air circulation around the plant to help reduce the spread of the disease.
Bacterial diseases: Bacterial wilt is another disease that can affect Argyrolobium rupestre subsp. kilimandscharicum. It will usually cause wilting and death of the whole plant. There is no cure for bacterial wilt, so affected plants should be removed and destroyed to help prevent the spread of the disease.
Common Pests
Aphids: Aphids are common pests that can affect Argyrolobium rupestre subsp. kilimandscharicum. They can usually be identified by their green or brown bodies and can cause significant damage to the leaves and stems of the plant. To manage aphids, you can rinse the plant with a strong jet of water or use insecticidal soap. You can also introduce natural predators like ladybugs to help control the population of aphids.
Spider mites: Spider mites are tiny pests that can cause a lot of damage to the leaves of Argyrolobium rupestre subsp. kilimandscharicum. They are usually identified by their webbing and tiny size. To manage spider mites, you can wash the plant with a strong jet of water or use a miticidal spray. You can also introduce natural predators like predatory mites to help control the population of spider mites.
Cutworms: Cutworms are common pests that can cause significant damage to the stems and roots of Argyrolobium rupestre subsp. kilimandscharicum. They are usually identified by their brown or gray striped bodies. To manage cutworms, you can use insecticidal baits or introduce natural predators like parasitic wasps to help control their population.
By following these simple steps to manage diseases and pests, you can help ensure the health and longevity of your Argyrolobium rupestre subsp. kilimandscharicum plants.
