Overview
Lathyrus davidii, commonly known as "David's Pea," is a perennial herbaceous plant that belongs to the Fabaceae family. The plant is endemic to China and can be found in various provinces, including Sichuan, Hunan, Guizhou, and Yunnan.
Appearance
Lathyrus davidii grows up to 1.5 meters tall and has a climbing or twining habit. The plant features slender stems that are green to purplish in color, with thin and slightly curved tendrils. The leaves are pinnate, comprised of several pairs of elliptic leaflets, and arranged alternately along the stem. The flowers are clustered in racemes, with each inflorescence bearing up to 20 pink to purple flowers. The fruit is a linear pod containing wrinkled, smooth, shiny seeds.
Common Names
Aside from "David's Pea," Lathyrus davidii is also known as "Purple Peavine" or "Chinese Sweet Pea."
Uses
Lathyrus davidii is primarily grown as an ornamental plant, thanks to its attractive pink-to-purple flowers. It is often used as a climber or grown on a trellis. In traditional Chinese medicine, the plant is believed to have medicinal value and is used to treat a range of ailments, including arthritis, rheumatism, and pulmonary tuberculosis.
Light Requirements
Lathyrus davidii thrives in full to partial sunlight. It requires at least six hours of direct sunlight daily to grow optimally. Too much shade will lead to extended growth and weak stems.
Temperature Requirements
The ideal temperature range for Lathyrus davidii growth lies between 18 to 24°C (64 to 75°F). It can tolerate warmer temperatures, but prolonged exposure to high temperatures may stunt its growth and affect its overall development.
Soil Requirements
Lathyrus davidii prefers well-draining soil rich in organic matter. The soil should be slightly acidic with a pH between 5.5 to 6.5. It can grow in loamy or sandy soils provided they contain a sufficient amount of nutrients. Waterlogged soils can cause root rot, so it's crucial to ensure proper drainage.
Fertilizer should be added to the soil before planting to ensure the plant has access to adequate nutrients throughout its growth cycle. Adequate soil moisture is necessary to promote optimal growth without overwatering, as excessive moisture in the soil can cause root rot.
Cultivation Methods
Lathyrus davidii, commonly called vining peavine or purple vetch, grows well in well-drained soils with a neutral to slightly alkaline pH. It thrives in full sun or partial shade and requires support from trellises or fences.
Propagation is typically done through the use of seeds, which can be sown directly in the garden in the spring or started indoors about six weeks before the last frost. When transplanting, space the plants about 6-8 inches apart.
Watering Needs
While Lathyrus davidii prefers well-drained soils, it still requires regular watering to establish and maintain healthy growth. Water the plants deeply once a week, providing about 1-2 inches of water. Avoid overwatering, as it can lead to root rot and other diseases.
During periods of drought, more frequent watering may be necessary. In general, it's better to provide deep watering less frequently than light watering more often.
Fertilization
To ensure healthy growth and flowering, it's recommended to fertilize Lathyrus davidii with a balanced fertilizer once a month during the growing season. A slow-release or organic fertilizer can also be used at planting time.
Before adding any type of fertilizer, it's important to test the soil to determine its nutrient needs. This can help you select the right type and amount of fertilizer.
Pruning
Pruning is an essential maintenance practice that helps promote fuller growth, increase flowering, and maintain plant size. It involves removing dead, damaged, or diseased stems and branches, as well as any growth that's out of place or detracts from the plant's overall appearance.
In general, Lathyrus davidii benefits from annual pruning in late winter or early spring before new growth begins. Cut back the old stems to about 6 inches from the ground to encourage new growth and flowering.
Propagation of Lathyrus davidii
The Lathyrus davidii plant can be propagated through four methods: seed propagation, stem cutting propagation, layering propagation and division propagation. Proper care must be taken to ensure the propagation methods are successful.
Seed propagation
Seed propagation involves collecting seeds from the plant and sowing them in well-draining soil. The best time to collect the seeds is after the plant completes flowering. The seeds should be sown in the autumn season immediately after collection. The seeds will germinate within a few weeks if provided with the right temperature, moisture and sunshine. Young saplings are then transplanted into containers or out in the garden after they develop strong roots.
Stem cutting propagation
Stem cutting propagation involves taking cuttings from the Lathyrus davidii plant and rooting them in soil. Select a healthy section of a stem that does not have any flowers or buds. Cut the stem about 6 inches long, and clear off any leaves from the lower end. Dip the cut end in rooting hormone and plant it in moist, well-draining soil. Keep the soil moist and provide the cutting with some shade until the roots develop. After the roots develop, the sapling can be transplanted into the garden or a larger container.
Layering propagation
Layering propagation involves bending a branch of the Lathyrus davidii plant down to the ground and then partially burying it. Tip of the branch is kept above the ground. The buried part of the branch will now start to produce roots. The new plant can then be separated from the original one by cutting the branch. It can then be transplanted into the garden or a larger container.
Division propagation
Division propagation involves dividing the plant’s root system into two or more sections small enough to each support a separate plant. This can be done by digging up the plant and separating its roots into sections, making sure each section has some roots as well as some stem. Transplant the divided sections into a new container or place them into the garden.
Disease and Pest Management for Lathyrus davidii
Lathyrus davidii, commonly known as the vining Chinese pea or David’s perennial sweet pea, is generally considered to be a hardy plant with few pest or disease problems. However, it is still important to be aware of some of the common diseases and pests that may affect the plant and ways to manage them.
Diseases:
Root Rot: This disease is caused by overwatering and poor drainage, which can lead to the roots of the plant becoming waterlogged and eventually rotting. To prevent this disease, make sure to plant Lathyrus davidii in well-draining soil and allow the soil to dry slightly between waterings.
Mildew: Powdery mildew is a common fungal disease that can affect Lathyrus davidii. It typically appears as a white or grayish-white powdery substance on the leaves and stems of the plant. To manage this disease, remove affected plant parts and use a fungicide according to the instructions on the label.
Pests:
Aphids: These small, soft-bodied insects can feed on the leaves and stems of Lathyrus davidii, causing stunted growth and distortion of the plant. To manage aphids, spray the plant with water to dislodge them or use an insecticidal soap or oil according to the instructions on the label.
Spider Mites: These tiny pests are difficult to see but can cause significant damage to Lathyrus davidii. They feed by piercing the plant cells and sucking out the juices, which can lead to yellowing leaves and stunted growth. To manage spider mites, use a miticide according to the instructions on the label.
Overall, Lathyrus davidii is a relatively easy plant to care for and is not often affected by serious pests or diseases. However, it is important to monitor the plant for any problems and take appropriate action to manage them as soon as they are detected.
