Perilla frutescens (L.) Britt. var. frutescens
Perilla frutescens (L.) Britt. var. frutescens, also known as shiso or beefsteak plant, is an annual herb belonging to the mint family Lamiaceae. It is native to East Asia and is widely cultivated in Japan, Korea, China, and India.
Common Names
The plant is known by various common names depending on the region, including Chinese basil, wild basil, purple mint, and perilla leaf. In Korea, it is called deulkkae, while in Japan, it is known as shiso.
Uses
Perilla is widely used in Asian cuisine for its distinctive flavor and aroma. Its leaves and seeds are used as a spice in many dishes, including sushi, stir-fries, and soups. The leaves are also used to wrap food items and as a garnish. In addition to its culinary uses, perilla is used in traditional medicine in China, Korea, and Japan to treat a variety of ailments, including allergies, asthma, and nausea.
General Appearance
Perilla is an annual plant that typically grows to a height of two to three feet. It has broad, serrated leaves that are usually green on top and purplish-red or bronze on the underside. The plant produces small, white or pinkish flowers in late summer, followed by oval-shaped fruits that contain small black or brown seeds. Perilla is a hardy plant that can grow in a range of soils and climates, but it prefers well-drained soils and full sun to partial shade.
Light Requirements
Perilla frutescens is a sun-loving plant that requires at least 6 hours of direct sunlight each day. To ensure optimal growth, it is recommended to grow Perilla frutescens in areas with full sun exposure, as partial shade can negatively affect plant growth and development.
Temperature Requirements
Perilla frutescens is a warm-weather plant that thrives in temperatures between 18 and 27 degrees Celsius. Temperatures below 10 degrees Celsius can severely impair plant growth and development. Perilla frutescens is sensitive to frost and should be protected in cold weather.
Soil Requirements
Perilla frutescens prefers well-drained soil that is rich in organic matter. A soil pH of 6.0 to 7.5 is ideal for optimal growth. The plant can tolerate various soil types, including loamy, sandy, and clay soils. However, it is important to avoid waterlogged and poorly aerated soils, as they can cause root rot and hinder plant growth.
Cultivation of Perilla frutescens (L.) Britt. var. frutescens
Perilla frutescens is a hardy plant and can be grown in most types of soil, ranging from sandy to loamy. The plant prefers a well-draining soil with a pH range of 6.0 to 7.5.
The ideal temperature range for the growth of Perilla frutescens is between 20-25°C. The plant requires full sun exposure for optimal growth.
The optimal time for sowing Perilla frutescens seeds is in early spring, after the last frost. The seeds should be sown just below the soil surface and kept moist until germination occurs. The plant can also be propagated by stem cuttings.
Watering Needs of Perilla frutescens
Perilla frutescens requires moderate watering. The plant should be watered once or twice a week, depending on the soil type and weather conditions. The soil should be allowed to dry out slightly between waterings to prevent root rot.
Overwatering should be avoided as it can lead to fungal diseases and damage the plant's growth and development.
Fertilization of Perilla frutescens
Perilla frutescens is a moderate feeder and requires regular fertilization for optimal growth and development. Fertilizers rich in potassium and phosphorous should be applied during the growing season.
Compost and well-rotted manure can also be added to the soil to provide the plant with essential nutrients.
Pruning Perilla frutescens
Perilla frutescens does not require extensive pruning and can be left to grow naturally. However, pruning can be carried out to control the size and shape of the plant.
Pruning should be done after the plant has finished flowering. The plant can be pruned to remove any dead or diseased branches and to promote the growth of new branches.
Propagation of Perilla frutescens (L.) Britt. var. frutescens
Perilla frutescens (L.) Britt. var. frutescens, also known as Korean perilla or shiso, can be propagated through various methods:
Seed propagation
The most common method of propagating Perilla frutescens is through seeds. The seeds should be sown in well-drained soil in spring or early summer. They should be planted at a depth of 1/4 to 1/2 inch in rows spaced 12 to 18 inches apart. Germination usually occurs within 10 to 14 days, and the seedlings should be thinned to 6 to 8 inches apart.
Stem cuttings
Perilla frutescens can also be propagated through stem cuttings. Take cuttings from healthy and established plants in late spring or early summer. Cuttings should be about 3 to 4 inches long and have at least 2 to 3 sets of leaves. Remove the lower set of leaves and dip the cuttings in rooting hormone powder. Plant the cuttings in well-draining soil and keep them moist until they root, which usually takes about 2 to 3 weeks.
Division
Another method of propagating Perilla frutescens is through division. Divide the plants in early spring before new growth starts or in early fall after the harvest period ends. Carefully dig up the plants and separate the root clumps. Replant the clumps in well-draining soil, making sure to keep the soil moist until new growth appears.
Disease Management
Perilla frutescens (L.) Britt. var. frutescens is susceptible to some fungal, bacterial, and viral diseases that can negatively impact plant health and productivity. Here are some common diseases that affect this plant and ways to manage them:
Downy Mildew
The downy mildew pathogen, Peronospora manhshurica, can cause yellow to gray lesions on leaves and a white powdery growth on the undersides of leaves. Control measures include crop rotation, removal of infected plant material, and the use of fungicides, like copper-based ones. Ensure proper ventilation to reduce humidity.
Anthracnose
The Colletotrichum acutatum fungus is responsible for this disease, which causes small, sunken brown spots on leaves. At times, these spots can encircle stems and cause death of the whole plant. Crop rotation along with sanitation and hygiene is recommended to control the disease.
Rhizoctonia stem rot
This disease, caused by Rhizoctonia solani, leads to wilting, yellowing and drying out of leaves and may occur in seedlings, young plants, and mature plants. Prevention through proper plant handling, irrigation practices, fertilization and rotation can help avoid the disease.
Pest Management
Apart from diseases, Perilla frutescens can also be affected by various pests. Here are some common pests that may harm Perilla frutescens plants and how to manage them:
Leafhoppers
Leafhoppers are common in gardens and are capable of transmitting plant diseases, such as aster yellows and phytoplasm. They can easily be excluded by the use of exclusion nets.
Whiteflies
Whiteflies are tiny sap-sucking insects found under the leaves of many plants, which cause yellowing and wilting of leaves. Control measures include using yellow sticky traps and removing heavily infested leaves. Insecticidal soaps and horticultural oils can also be used.
Aphids
Aphids are tiny insects that feed on sap from the leaves and stem. They can be controlled using insecticidal soaps or horticultural oils as well as by using predators such as ladybugs or parasitic wasps.
