Overview of Zoysia japonica Steud.
Zoysia japonica Steud. is a perennial grass species in the family Poaceae. It is a warm-season grass that is native to East Asia, including China, Japan, and Korea. This plant is commonly known as Korean lawngrass, Japanese lawn grass or simply Zoysia.
General Appearance of Zoysia japonica Steud.
Zoysia japonica Steud. has a fine texture and is characterized by an attractive, dense, and uniform growth habit. It has a slow growth rate and a low to moderate height, with a mature height of 2-4 inches. The plant produces green, narrow, and pointed leaves, which are around 2-4 mm wide and up to 15 cm long. It has a deep root system, which makes it highly drought-resistant.
Uses of Zoysia japonica Steud.
Zoysia japonica Steud. is a popular choice for lawns, golf courses, and other recreational areas. It is highly valued for its attractive appearance, low maintenance requirements, and excellent tolerance to heat and drought. Zoysia grass is also used for erosion control, as it effectively stabilizes soil and reduces water runoff. Additionally, the grass is used for grazing in some regions due to its nutritional value and palatability to livestock.
Cultivation of Zoysia japonica Steud.
Zoysia japonica Steud. is a warm-season grass that grows best in areas with hot summers and mild winters. It prefers well-drained soil and full sun to partial shade. The plant can be propagated through seeds, but this method is not commonly used. More frequently, Zoysia is grown through vegetative means, such as sod or plugs. It requires low to moderate maintenance, with fertilization and watering needs depending on the climate and soil conditions. Additionally, it is important to note that Zoysia grass may become invasive, and should be monitored in areas where it is introduced.
Light Requirements
Zoysia japonica Steud. thrives well in full sunlight but can grow in partial shade. It requires at least four to six hours of direct sunlight every day for optimal growth. However, excessive shade reduces the plant's growth rate and affects its density. Therefore, it is essential to plant the Zoysia japonica Steud. in an area where it can receive enough sunlight.
Temperature Requirements
Zoysia japonica Steud. does well in warm temperatures, and it is incredibly drought-tolerant. The ideal temperature range for the plant is between 75 and 90 degrees Fahrenheit (24-32°C). When the temperature falls below 50 degrees Fahrenheit (10°C), the plant becomes dormant and turns brown. However, once the temperature rises again, it quickly bounces back to life.
Soil Requirements
Zoysia japonica Steud. prefers well-aerated soils and thrives in sandy and loamy soils that are slightly acidic. The soil pH should range between 5.5 and 7.5. Soil testing is crucial to determine whether the soil is deficient in essential nutrients. Zoysia japonica Steud. requires proper soil drainage because it does not tolerate waterlogged soils and is susceptible to pests and diseases caused by saturated soil conditions.
Cultivation Methods
Zoysia japonica Steud., also known as Korean or Japanese lawn grass, is a warm-season grass that thrives in full sun to partial shade. It grows well in sandy, loamy, or clay soils and can tolerate some drought conditions once established. To cultivate Zoysia japonica, it is best to plant seeds or sod in spring or early summer when the soil temperature is above 60°F (15°C).
Prepare the soil by tilling it deeply, removing weeds and rocks, and adding organic matter like compost or peat moss. Spread the seeds or sod evenly and cover lightly with soil. Water the area well and keep it moist until the grass seeds or roots are established.
Watering Needs
Zoysia japonica requires about 1 inch of water per week, either from rainfall or irrigation, to maintain its green color and healthy growth. It is important to water deeply and infrequently, rather than shallow and frequently, to encourage the roots to grow deeper and become more drought-resistant.
During hot and dry weather conditions, you may need to water Zoysia japonica more frequently, adding another 0.5 to 1 inch of water per week. However, avoid overwatering as it can lead to shallow roots, disease, and other problems.
Fertilization
To keep Zoysia japonica healthy and lush, it is recommended to fertilize it regularly with a balanced fertilizer that has equal amounts of nitrogen, phosphorous, and potassium. You can apply fertilizer during the growing season, which is from early spring to late fall, at a rate of 1 pound of nitrogen per 1000 square feet of area.
If the soil pH is too low or too high, you may need to add lime or sulfur to adjust it before fertilizing. Also, it is recommended to do a soil test every 2 to 3 years to determine the soil's nutrient content and pH level and adjust the fertilization accordingly.
Pruning
Zoysia japonica requires minimal pruning compared to other grasses. However, it is recommended to mow it regularly at a height of 1 to 2 inches to encourage thick growth and prevent weeds from invading the lawn. It is best to use a sharp mower blade and avoid cutting more than one-third of the grass height in one mowing.
You can also use a grass catcher to collect the clippings and avoid smothering the grass with too much debris. Additionally, it is best to avoid mowing Zoysia japonica when it is wet or stressed, as it can damage the grass blades and roots.
Propagation of Zoysia japonica Steud.
Zoysia japonica Steud. can be propagated by various methods, including seeding, plugs or sod, and vegetative propagation.
Seeding
Seeding is the most common method of propagation for Zoysia japonica Steud. This method involves planting seeds in soil and allowing them to germinate and grow into mature plants. Seeds are usually planted in the spring or summer, and the soil should be moist and warm for successful germination. It is important to keep the soil moist during the germination process and to provide adequate sunlight for the plants to grow.
Plugs or Sod
Plugs or sod are another method of propagating Zoysia japonica Steud. This involves planting small pieces of grass called plugs or large pieces of grass called sod directly into the soil. This method allows for faster establishment of the grass and is particularly useful for creating an instant lawn. Plugs or sod should be planted in the spring or summer, and the soil should be moist and warm for successful growth.
Vegetative Propagation
Vegetative propagation is a method of propagation that involves taking cuttings or divisions of mature plants to create new plants. This method is particularly useful for creating a large number of genetically identical plants quickly. To propagate Zoysia japonica Steud. through vegetative propagation, mature plants are divided into smaller sections and replanted in soil. These smaller sections will grow into mature plants. Alternatively, cuttings can be taken from mature plants and planted in soil to create new plants.
Disease Management
Zoysia japonica Steud. is generally resistant to diseases but can still be affected by some common disorders.
Brown Patch: A fungal disease, brown patch, can affect Zoysia japonica Steud. during hot and humid weather conditions. It is characterized by the appearance of small, circular patches with brownish or yellowish color. To manage this disease, avoid using excessive nitrogen fertilizer, improve the drainage of the lawn, remove thatch buildup, and irrigate only when needed.
Fairy Ring: A fungal disease, fairy ring, can appear as dark green circles with dead or dying grass in the center. It is caused by a fungus that decomposes organic matter in the soil, producing gas that inhibits the growth of grass. To manage this disease, you can aerate the soil, remove the thatch, and maintain good soil moisture. You can also apply fungicides.
Pest Management
While Zoysia japonica Steud. is relatively pest-resistant, some insects can cause damage to the plant.
Chinch Bugs: Chinch bugs are small insects that cause yellowish patches on the lawn. They suck the sap from the blades of grass, causing them to dry up and die. To manage chinch bugs, you can use insecticidal soap or neem oil. You can also maintain good soil moisture and reduce the use of nitrogen fertilizers.
Grubs: Grubs are the larval stage of various beetles. They feed on the roots of Zoysia japonica Steud., causing it to wilt and die. To manage grubs, you can apply Bacillus thuringiensis (Bt) to the soil or use insecticides. You can also attract birds that feed on grubs, like robins and starlings.
Mole Crickets: Mole crickets are insects that burrow into the soil, creating tunnels that can damage the roots of Zoysia japonica Steud. They can also feed on the blades of grass, causing it to wilt and die. To manage mole crickets, you can use insecticides or apply nematodes to the soil. You can also attract birds that feed on mole crickets, like blue jays and crows.
