Origin and Common Names
Crotalaria sagittalis L. var. oblonga Michx. is a perennial flowering plant species belonging to the family Fabaceae. The plant is native to the southeastern United States, where it grows in sandy soils, and can be found in coastal areas from North Carolina to Texas. It is commonly known as arrowleaf rattlebox due to its distinctive arrow-shaped leaves and the sound made by the seeds in its rattling pods when shaken.
General Appearance
The plant typically grows up to 2.5 feet tall, with a slender, erect stem that is covered in fine hairs. It has alternate, compound leaves that are grayish-green, arrow-shaped, and about 3 inches long. The flowers are yellow and pea-shaped, and bloom in the summer months. Once pollinated, the plant produces long, narrow seed pods that rattle when shaken due to their enclosed seeds.
Uses
Crotalaria sagittalis L. var. oblonga Michx. has several uses. Historically, Native Americans used the plant for medicinal purposes, to treat dysentery, fever, and skin conditions, and the roots as a poultice to reduce swelling and inflammation. The plant is also used as a cover crop in agricultural fields because it is a nitrogen-fixer and can improve soil fertility. However, it is important to note that all parts of the plant are toxic to livestock and can cause liver damage or death if ingested in large amounts. Therefore, it is not recommended to plant it in pastures where livestock may graze.
Light Requirements
Crotalaria sagittalis L. var. oblonga Michx. plants prefer full sunlight exposure. These plants require at least six hours of direct sunlight every day.
Temperature Requirements
Crotalaria sagittalis L. var. oblonga Michx. plants thrive in warm temperatures. The ideal temperature range for these plants is between 60 and 85°F (15 and 29°C). Colder temperatures can lead to poor growth and potential damage to the plant.
Soil Requirements
Crotalaria sagittalis L. var. oblonga Michx. plants prefer well-drained, loamy soils that are rich in nutrients. These plants can tolerate a broad range of soil pH, but they prefer slightly acidic soils between 5.5 and 6.5. Adding organic matter or compost to the soil can also enhance the plant's growth and health.
Cultivation Methods
Crotalaria sagittalis L. var. oblonga Michx. is a warm-season plant and can be grown in USDA hardiness zones 9-11. It is a relatively low-maintenance plant and grows well in sandy soil with good drainage. The plant can be propagated through seedlings or sowing seeds in the spring or early summer. It is recommended to plant them at a distance of 12-24 inches apart to allow proper root growth and development.
Watering Needs
Crotalaria sagittalis L. var. oblonga Michx. requires moderate watering during the growing season. It needs watering once or twice a week, depending on the weather conditions and soil type. Overwatering or watering too infrequently can result in stunted growth or root rot. It is recommended to water the plant in the early morning or late afternoon to avoid evaporation and to allow the plant to absorb the water effectively.
Fertilization
Crotalaria sagittalis L. var. oblonga Michx. benefits from a balanced fertilizer application during the growing season. A slow-release fertilizer or a balanced fertilizer with equal parts nitrogen, phosphorus, and potassium can be applied once or twice during the growing season. Over-fertilizing can result in leggy growth and low flower production. Follow the manufacturer's instructions and avoid getting the fertilizer on the leaves or stems to prevent burning the plant.
Pruning
Crotalaria sagittalis L. var. oblonga Michx. requires little pruning. However, deadheading of flowers is recommended to promote continuous blooming and to prevent the plant from wasting energy on producing seeds. Removing any dead or diseased leaves can also help the plant grow healthier and look more attractive. Pruning should be done during the growing season and should be minimal to avoid damaging the plant's growth and form.
Propagation of Crotalaria sagittalis L. var. oblonga Michx.
Crotalaria sagittalis L. var. oblonga Michx. can be propagated by various methods, including seeds, stem cuttings, and root cuttings.
Propagation through Seeds
Seeds of C. sagittalis L. var. oblonga Michx. can be sown directly into the ground or in containers filled with well-draining soil mixture. The best time to sow seeds is during the early spring when the weather begins to warm up.
The seeds should be covered with a thin layer of soil, watered, and placed in a warm and bright location. Germination usually occurs within two to three weeks, and seedlings can be transplanted when they are about four to six inches tall.
Propagation through Stem Cuttings
Crotalaria sagittalis L. var. oblonga Michx. can also be propagated through stem cuttings. The cuttings should be taken from healthy and disease-free plants that are actively growing during the summer months. Cuttings should be four to six inches in length and should be taken from the plant's softwood growth.
The bottom of the stem should be dipped into a rooting hormone, and then planted in moist and well-draining soil mixture. The cutting should be placed in a warm and humid location and should be watered regularly. Roots should form within a few weeks, and the new plant can be transplanted to a larger container or directly into the ground.
Propagation through Root Cuttings
Propagation of C. sagittalis L. var. oblonga Michx. through root cuttings is possible but is less common. The roots should be dug up during the dormant period, and cut into pieces that are about two to three inches in length. The root cuttings should be planted in containers filled with well-draining soil mixture and placed in a warm location.
The cuttings should be kept moist but not waterlogged, and roots should form within a few weeks. Once the new plant has established, it can be transplanted to a larger container or directly into the ground.
Disease and Pest Management for Crotalaria sagittalis L. var. oblonga Michx
As with any plant, Crotalaria sagittalis L. var. oblonga Michx. is susceptible to a variety of pests and diseases. Proper management of these issues is critical to ensure the plant thrives.
Common Diseases:
Two common diseases that can affect Crotalaria sagittalis L. var. oblonga Michx. are fungal leaf spot and root rot. Fungal leaf spot is a common disease in humid environments and can lead to the yellowing and browning of the plant's leaves. Root rot is caused by overwatering and can cause the plant to wilt and die.
Disease Management:
To manage fungal leaf spot, ensure proper air circulation around the plant and avoid watering the foliage. If necessary, fungicides can be used according to the manufacturer's instructions. For root rot, ensure the plant is not being overwatered and improve soil drainage. Applying a fungicide to the soil could also be beneficial, if the infection is severe.
Common Pests:
Common pests that can affect Crotalaria sagittalis L. var. oblonga Michx. include aphids, spider mites, and caterpillars. Aphids and spider mites can cause damage to the plant by sucking sap from the leaves. Caterpillars can cause physical damage by feeding on the plant's leaves
Pest Management:
Regularly inspecting the plant for pests and removing them manually is the best way to manage them. Insecticidal soap can be applied according to the manufacturer's instructions to control aphids and spider mites. Bacillus thuringiensis, a natural bacterial insecticide, can be used to manage caterpillars if the infestation is severe.
With proper care and disease and pest management, Crotalaria sagittalis L. var. oblonga Michx. can thrive and remain healthy.
