Stevia salicifolia Cav.
Stevia salicifolia Cav. is a species of plant from the Asteraceae family. It is commonly known as the “Tucumaní” or “Caá-he-é” and is native to South America, specifically southern Brazil, Paraguay, and Argentina.
Appearance
The plant has a shrubby habit and can grow up to 1.5 meters tall. It has narrow, elongated leaves that are lanceolate in shape and green in color. The leaves are toothed and have a smooth texture. The plant also produces tiny white flowers that are arranged in clusters.
Uses
The Stevia salicifolia plant contains a compound called stevioside, which is known for its extremely sweet taste. This compound is commonly used as a natural sweetener in food and beverage products, such as tea and coffee. In addition to its sweetening properties, the plant is also believed to have medicinal properties and has been used in traditional medicine as a treatment for a variety of ailments, including diabetes, hypertension, and digestive issues.
As an ornamental plant, Stevia salicifolia is often included in gardens and landscaping due to its attractive appearance.
Cultivation
Stevia salicifolia is a hardy plant that can thrive in a range of growing conditions. It prefers well-draining soil and partial shade, although it can also grow in full sun. The plant is drought-tolerant and can survive in dry conditions for extended periods. It can also be propagated from seed or by cuttings.
In recent years, Stevia salicifolia has gained popularity as an alternative to the commonly grown Stevia rebaudiana due to its superior flavor and ease of cultivation.
Light Requirements
Stevia salicifolia Cav. requires a lot of sunlight for optimal growth. The plant thrives in locations that receive direct sunlight for most of the day. Therefore, it is important to ensure that the plant is exposed to at least six hours of sunlight daily. If the plant is grown indoors, it is important to place it close to a south-facing window or an area that receives a lot of natural light.
Temperature Requirements
Stevia salicifolia Cav. prefers warm temperatures. The ideal temperature range for the plant is between 18°C and 32°C (65°F to 90°F). The plant is highly sensitive to frost and cannot survive in temperatures below 0°C (32°F). In areas with colder temperatures, it is advisable to grow the plant indoors in a warm and humid environment.
Soil Requirements
Stevia salicifolia Cav. is not too demanding in terms of soil requirements. The plant does well in well-draining soil that is rich in organic matter. The pH of the soil should be between 6.5 to 7.5. The soil should be moist but not waterlogged, consistently providing sufficient moisture to the roots. It is important to avoid overwatering since it can lead to root rot and other fungal diseases.
Cultivation methods
Stevia salicifolia Cav. is a perennial herb that is highly tolerant and can grow in a variety of soils and climates. However, it thrives best in well-drained, slightly acidic soils with good organic matter content. The plant can be propagated using cuttings or seeds. If using seeds, they should be planted in well-prepared seedbeds and covered with a thin layer of soil. For cuttings, select healthy stems and remove the lower leaves. The cuttings should then be planted in moist soil and kept in a moist environment for rooting to take place.
Watering needs
Stevia salicifolia Cav. requires moderate watering but can withstand minor droughts. The plant should be watered regularly during the growing season and less frequently during the dormant period. It's essential to avoid overwatering as this can lead to root rot and other diseases. Watering should be done at the base of the plant to avoid wetting the leaves, which can cause fungal diseases.
Fertilization
The plant requires regular fertilization to maintain healthy growth and high yields. It's best to fertilize during the growing season when the plant is actively growing. Use a balanced fertilizer with an N:P:K ratio of 10:10:10 or a similar formulation. The fertilizer should be applied at the base of the plant, and care should be taken not to apply too much fertilizer, which can damage the roots or cause leaf burn.
Pruning
Pruning helps to maintain the plant's shape, encourage bushier growth, and prevent the plant from becoming too leggy. Stevia salicifolia Cav. should be pruned regularly during the growing season. Remove any damaged or diseased leaves, stems, or branches. Pinch back the tips of the plant when it reaches a height of 6 inches, and continue to pinch back every six weeks to maintain bushy growth. Pruning should be done carefully to avoid damaging the plant.
Propagating Stevia salicifolia Cav.
Stevia salicifolia Cav., also known as the bamboo-leaf stevia, is commonly propagated through stem cuttings, division, and seeds.
Stem Cuttings
Stem cuttings are the most common propagation method for Stevia salicifolia because the plant is sterile. Cuttings of around 10 cm length can be taken from the dormant or semi-dormant wood in the early spring. The cuttings should be done from mature wood that has already produced inflorescences, ensuring a high percentage of successful rooting.
After taking the cutting, remove the leaves from the bottom part and dip the cut end into a rooting hormone. Then, plant the cuttings into well-draining soil, keeping them moist, but not waterlogged. Cover the cuttings with a plastic bag or a cloche to retain moisture and place them in a bright spot with indirect light. In a few weeks, new roots and leaves will emerge, indicating that the plant has rooted and is growing well.
Division
Stevia salicifolia can also be propagated through division. In the spring, when the plant starts to green up, the clumps can be divided with a sharp, sterile knife. Each clump must have at least one section of rhizome, which is the underground stem. The divided sections can be then planted into well-draining soil, keeping them moist until they establish new roots and start to grow new leaves.
Seeds
Seeds can also be used to propagate Stevia salicifolia. However, propagation by seeds is not recommended because the plant under natural conditions is an apomictic species and most plants produced in this way usually show a wide range of characteristics that are not typical of the parent plant.
When using seeds, sow them in a well-draining soil in early spring, keeping the soil moist. Expect germination after 7-14 days.
Regardless of the propagation method chosen, newly propagated Stevia salicifolia plants must be grown in well-draining soil and placed in a bright spot with indirect light until they establish and form new roots and leaves.
Disease Management:
Stevia salicifolia Cav. is generally considered a disease-resistant plant. However, it can be susceptible to fungal diseases like leaf spot, powdery mildew, and rust. To prevent the occurrence of these diseases, always keep your plant's surroundings clean and dry. Be sure not to overcrowd your plants, as this can increase humidity levels and create an ideal environment for fungal growth. In case of severe infestations, use copper-based fungicides, making sure to follow the recommended dosage.
Pest Management:
Stevia salicifolia Cav. is relatively pest-resistant. Still, some common pests, such as aphids, whiteflies, and spider mites, can sometimes infest the plant. To manage these pesky critters, introducing natural predators like ladybugs, lacewings, or parasitic wasps can be effective. For minor infestations, blasting the pests off the plant with a strong stream of water can help. You can also use insecticidal soap or neem oil to control the infestation.
It's essential to note that pesticides should always be the last resort in managing pests. They have negative effects not only on the pests but also on beneficial insects like bees, butterflies, and birds.
