Overview
Stevia lemmonii (Gray) Gray is a perennial herbaceous plant belonging to the Asteraceae family. It is commonly known as Lemmon's stevia, wild sweetleaf, or Yerba Dulce. The plant originates from Arizona, New Mexico, and northern Mexico.
Appearance
The plant grows up to 6 feet tall and is characterized by small and slender leaves. Its leaves are triangular, toothed on the edges, and have hairs on both surfaces. The stem is light green and stands erect. The leaves of Stevia lemmonii have a sweet fragrance, which is responsible for its common name, wild sweetleaf.
Uses
Stevia lemmonii is a medicinal plant used by Native Americans to treat various health conditions such as coughs, fevers, and stomach aches. It is believed to possess analgesic, anti-inflammatory, and anti-bacterial properties, making it useful for wound healing.
The plant is also a source of natural sweeteners. Steviol glycosides, which can be extracted from the leaves of Stevia lemmonii, are 200 to 300 times sweeter than regular sugar. This makes it a healthier alternative to sugar for individuals with diabetes or those seeking to reduce sugar intake.
Stevia lemmonii is also a popular ornamental plant in gardens and landscaping, thanks to its attractive foliage and sweet fragrance.
Cultivation
Stevia lemmonii is best grown in regions with a warm and sunny climate. It prefers well-drained soils and moderate watering. The plant can be propagated through seeds or cuttings and requires occasional pruning to maintain its shape.
The cultivation of Stevia lemmonii as a commercial crop is gaining popularity due to the high demand for natural sweeteners. However, much work remains to be done in developing the best cultivation practices for this plant.
Light Requirements
Stevia lemmonii requires partial shade to full sun exposure for optimal growth. The plant needs at least 4 hours of direct sunlight per day to carry out photosynthesis. However, excessive direct sunlight can scorch the leaves and damage the plant. It's best to provide some shade if the plant is grown in a hot climate to prevent stress due to high temperature.
Temperature Requirements
Stevia lemmonii thrives in warm temperatures ranging between 18-28 degrees Celsius. Temperatures below 10 degrees Celsius can be detrimental to the growth of the plant. It's important to protect the plant from frost or winter chills. Therefore the plant is recommended to be grown in USDA zones 8-11, although it can be grown in other zones with extra care.
Soil Requirements
The plant prefers well-drained, fertile, loamy soil with a pH range of 6.0-7.5. The soil should be rich in organic matter and high in potassium. Stevia lemmonii does not tolerate dry soil, and it needs moderate moisture to thrive. Additionally, the plant needs good airflow around its roots to prevent fungal disease from occurring. It's recommended to add compost or organic matter to the soil to improve soil structure and fertility.
Cultivation Methods for Stevia lemmonii (Gray) Gray
Stevia lemmonii (Gray) Gray can be cultivated either through seeds or cuttings. Seeds should be sown in a well-draining potting mix, and cuttings should be taken from a mature plant and planted in a rooting hormone in a well-draining potting mix. The plant is best grown in a warm climate with plenty of sunlight. It is frost-tender and must be protected from any frost or cold winds.
Watering Needs for Stevia lemmonii (Gray) Gray
Stevia lemmonii (Gray) Gray requires regular watering to keep the soil moist but not waterlogged. However, care must be taken to avoid overwatering as it may lead to root rot. The plant will do well with weekly watering or as needed, depending on the climate and season. In drier and hotter climates, more frequent watering may be necessary.
Fertilization for Stevia lemmonii (Gray) Gray
Stevia lemmonii (Gray) Gray requires regular fertilization to ensure healthy growth. The plant can be fertilized with a balanced fertilizer every two weeks during the growing season. Additionally, organic fertilizers such as compost and manure can be added to the soil to provide essential nutrients.
Pruning for Stevia lemmonii (Gray) Gray
Stevia lemmonii (Gray) Gray can become leggy if not pruned. Pruning encourages bushy growth and helps to maintain the plant's shape. Pruning should be done in late winter or early spring before new growth starts. The plant can be cut back to about half its height, and any dead or damaged branches can be removed. Additionally, pruning can be done throughout the growing season to remove any dead or diseased foliage.
Propagation of Stevia lemmonii (Gray) Gray
Stevia lemmonii (Gray) Gray, commonly known as Lemmon's stevia, is a perennial shrub that produces sweet compounds. If you want to propagate Stevia lemmonii, there are several methods available. In this article, we will discuss the most popular propagation techniques.
Seed Propagation
Seed propagation can be an easy and cost-effective method for growing Stevia lemmonii plants. Collect the seeds from a mature plant, and sow them in a well-draining potting mix. Keep the soil moist until sprouts emerge, which may take up to two weeks. Once the seedlings reach four inches tall, transplant them into larger containers or into a garden bed.
Cuttings Propagation
Cuttings propagation is another popular method for Stevia lemmonii plants. Take cuttings about six inches in length, and remove the leaves from the bottom half of each cutting. Dip the cuttings in rooting hormone, and plant them in a well-draining potting mix. Keep the soil consistently moist, but not overly wet. Place the container or pot in a bright, indirect light location. Over time, new roots should form, and the plant can be transplanted to a larger container or a garden bed.
Division Propagation
Division propagation is a method to produce several new Stevia lemmonii plants from one mature plant. Gently dig up the plant and divide it into sections with a sharp, sterile knife. Each section should have a good amount of roots attached. Replant the divided sections into well-draining potting mix. Keep the soil moist until the plants become established.
Air Layering
Air layering is a method to create new roots on a stem while it is still attached to the parent plant. Choose a young, flexible stem and wound it by removing a section of bark. Cover the wound with moist sphagnum moss, and wrap it with plastic wrap. After a few weeks, roots should begin to grow from the wound. Once the new roots are established, cut the stem below the rooted section and plant it in a well-draining potting mix.
Propagation allows you to grow multiple plants from one Stevia lemmonii mother plant. This will give you an opportunity to increase your yield of sweet leaves and enjoy their taste for a longer time.
Disease and Pest Management for Stevia lemmonii (Gray) Gray
Stevia lemmonii (Gray) Gray, commonly known as Lemmon's stevia, is a perennial herbaceous plant grown for its sweet-tasting leaves. This plant is vulnerable to various diseases and pests, which can significantly reduce its yield and quality.
Common Diseases
Leaf spot: This fungal disease is caused by the pathogen Cercospora spp. and is characterized by the appearance of yellow to brown spots on the leaves. It can be controlled by using proper sanitation practices, such as removing infected leaves and providing good air circulation. Fungicide application can also be effective in severe cases.
Root rot: This disease is caused by the fungus Rhizoctonia solani and is characterized by the wilting of leaves and stems. The roots may also appear dark brown and decayed. To manage this disease, it is essential to avoid overwatering and ensure proper drainage. Additionally, applying fungicides can be effective in controlling the spread of the fungus.
Common Pests
Aphids: These small insects feed on plant sap and can cause stunted growth and deformities in the leaves. They can be controlled by using insecticidal soap or neem oil. Preventive measures, such as maintaining good sanitation practices and using reflective mulches, can also reduce the risk of infestation.
Spider mites: These tiny pests suck the sap of the leaves, resulting in yellowing and discoloration. Infested leaves may also develop a fine webbing. To control spider mites, it is important to maintain high humidity levels and use miticides when necessary.
Whiteflies: These insects deposit a sticky substance on the leaves, causing stunted growth and deformation. They can be controlled with insecticidal soap or neem oil. Encouraging natural predators, such as ladybugs and lacewings, can also be effective in reducing the population of whiteflies.
