Origin and Common Names
Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster, commonly known as sand crabgrass, is a species in the grass family Poaceae. It is native to the southeastern United States, including Florida, Georgia, Alabama, Mississippi, and Louisiana.
Appearance
Sand crabgrass is a clumping, warm-season perennial grass that grows up to 1.2 meters (4 feet) tall. It has slender, cylindrical stems that are green to purplish in color and often shiny. The leaves are flat, narrow, and hairy, with a prominent midvein. The inflorescence is made up of several spikes, each measuring up to 18 centimeters (7 inches) long, with small spikelets that contain the flowers.
Uses
Sand crabgrass is primarily used as a forage grass for livestock and wildlife. It is also used as a soil stabilizer in coastal areas, where it helps prevent erosion. Additionally, sand crabgrass can be used as a cover crop in vegetable gardens and other agricultural areas to provide soil protection and increase soil organic matter.
Light Requirements
Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster typically requires full sun to partial shade to grow optimally. It can tolerate high levels of light but it may not perform well under low light conditions.
Temperature requirements
This plant can be grown in different temperature ranges, but it prefers warm temperatures. The optimal temperature range for its growth is approximately 20°C to 35°C. This plant can tolerate temperatures above and below this range, but the growth rate may decrease under extreme temperatures.
Soil requirements
Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster prefers well-drained soils with a pH range of 5.5 to 7.5. The soil should be moist but not waterlogged. This plant can grow in sandy soil, clay soil, and loamy soil. It can tolerate drought, but consistent moisture is ideal for optimal growth.
Cultivation methods
Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster is a warm-season grass that is commonly grown in sandy soil. It requires full sun exposure to grow and can tolerate alkaline soil conditions. It is also able to withstand drought and heat stress, making it a suitable choice for areas with low rainfall and high temperatures.
The best time to plant the grass is in the spring, after the last frost. The seeds should be sown on the soil surface and then lightly covered with soil. The recommended seed rate is 5-8 pounds per acre. The soil should be kept moist until the seeds germinate, which can take up to 14 days.
Watering needs
Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster requires moderate amounts of water to grow. It can withstand drought, but prolonged periods of dryness can cause the grass to turn brown and die. Therefore, it is recommended to water the grass once a week, providing enough water to moisten the soil to a depth of at least 6 inches.
It is important to avoid overwatering the grass, which can lead to waterlogging and root rot. Additionally, watering the grass in the early morning is recommended as it allows the grass to dry out during the day, reducing the risk of fungal diseases.
Fertilization
Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster requires regular fertilization to maintain its growth and health. An all-purpose fertilizer with a balanced ratio of nitrogen, phosphorus, and potassium is recommended. The fertilizer should be applied in the early spring, before the grass starts its active growth, and then again in the fall after the growing season ends.
It is important not to over-fertilize the grass, as this can lead to excessive growth, which can make the grass more susceptible to disease and require more mowing.
Pruning
Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster does not require regular pruning, but occasional trimming can help to maintain a neat and tidy appearance. The grass can be mowed to a height of 2-3 inches, with the blades of the mower set high to avoid damaging the grass.
It is important to avoid pruning the grass too close to the ground, as this can damage the roots and make the grass more susceptible to disease. Additionally, pruning the grass in the early morning or late afternoon is recommended, as this can help to avoid exposing the grass to the harsh midday sun.
Propagation of Digitaria cognata var. arenicola
There are primarily two methods of propagating Digitaria cognata var. arenicola:
Seed Propagation
The most common method of propagation for Digitaria cognata var. arenicola is through seed propagation. The plant produces abundant viable seeds that can be easily harvested. The best time to collect seeds is after seed heads have matured and turned brown.
Once harvested, clean the seeds and store them in a cool, dry place until you are ready to plant them. To plant the seeds, you can either directly sow them in the soil or start them indoors. If you decide to start the seeds indoors, plant them in pots or trays filled with well-draining soil mix, make sure to cover the seeds with a thin layer of soil, and keep the soil moist but not wet.
Vegetative Propagation
Another method of propagating Digitaria cognata var. arenicola is through vegetative propagation. This method is best done during the growing season, typically in the spring or early summer.
To propagate through vegetative means, locate healthy stem cuttings that have at least one node and are around 3-4 inches in length, making a clean cut right below the lowest node. Remove all leaves except the top two, and plant the cutting vertically in a well-draining soil mix, push down the soil to make sure it is firmly in place then water immediately.
It may take several months before the cutting is well established and during that period, keep the soil moist to encourage growth and reduce stress. Once the cutting has rooted, it will begin to sprout new leaves and will eventually become a fully formed plant.
Disease Management
Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster is susceptible to several diseases that may affect the growth and development of the plant. The following are some common diseases that affect the plant:
- Leaf Spot: This is a fungal disease that causes small, brown-black spots on the leaves. The disease spreads by splashing water, so it is important to avoid overhead watering. Fungicides can be used to manage the disease.
- Root Rot: This is a disease caused by soil-borne pathogens that affect the roots, causing them to rot. The plant may wilt and die if the disease is severe. It is important to ensure good drainage to prevent the disease. Fungicides can also be used to manage the disease.
- Virus Diseases: Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster is susceptible to several viruses that may cause stunting, mosaic patterns, and leaf distortion. The diseases spread by sap-sucking insects, such as aphids. The use of insecticides to manage the insects can help minimize the spread of the disease.
Pest Management
Digitaria cognata (J.A. Schultes) Pilger var. arenicola (Swallen) R. Webster is susceptible to several pests that may affect the growth and development of the plant. The following are some common pests that affect the plant:
- Aphids: These are small, sap-sucking insects that may cause the plant to wilt. The insects may also transmit viruses. Insecticides can be used to manage the insects.
- Spider Mites: These are small insects that may cause the leaves to yellow and become speckled. The insects may also produce webbing on the plant. Insecticides can be used to manage the insects.
- Grasshoppers: These are chewing insects that may cause significant damage to the plant by feeding on the leaves and stems. Insecticides can be used to manage the insects.
It is important to monitor the plant regularly for any signs of disease or pest infestations. Early detection can help prevent the spread of the disease or pests. It is also important to follow good cultural practices, such as removing infected plant materials and ensuring good drainage, to promote healthy plant growth.
