Overview
Astragalus decumbens (Nutt. ex Torr. & Gray) Gray var. oblongifolius (Rydb.) Cronq., also known as prostrate milkvetch, is a perennial plant that belongs to the family Fabaceae. It is a native species to North America and can be found in many regions of the United States, including California, Nevada, Utah, and Colorado. The plant is known for its ornamental value and medicinal properties.
Appearance
The prostrate milkvetch is a low-growing plant that typically reaches a height of 3 to 6 inches. The stems of the plant are prostrate and woody, with leaves that are brownish-green in color and elliptical or oblong in shape. The leaves are typically 0.3 to 1 inch long and have a slightly hairy texture. The flowers of the plant are small and pink in color, measuring only 0.1 to 0.2 inches in length. The plant blooms from May to August.
Uses
The prostrate milkvetch has several medicinal uses. The plant has been used in traditional medicine to treat a variety of ailments, including diarrhea, indigestion, and respiratory infections. The root of the plant is believed to contain compounds that have anti-inflammatory and antioxidant properties. Some studies have also suggested that the plant may have potential in treating certain forms of cancer.
Aside from its medicinal uses, the prostrate milkvetch is also valued for its ornamental qualities. The plant is often used in landscaping to provide low ground cover, and its tiny pink flowers add a splash of color to gardens and rock gardens.
Common Names
The prostrate milkvetch has several common names, including oblongleaf milkvetch, western milkvetch, and Nuttall's milkvetch. Other common names for the plant include ground plum, prairie plum, and buffalo plum.
Light Requirements
Astragalus decumbens var. oblongifolius prefers full sun to partial shade. It grows well in areas that receive at least 6 hours of direct sunlight per day. In shaded areas, the plant may become leggy and weak.
Temperature Requirements
The plant is native to arid regions of western North America and can withstand hot and dry conditions. It can tolerate temperatures as low as -10°C and as high as 40°C. It grows best in USDA hardiness zones 4 to 9.
Soil Requirements
Astragalus decumbens var. oblongifolius prefers well-drained soils that are moderately fertile and slightly acidic to neutral in pH. It can tolerate poor and rocky soils, as well as soils with low organic matter content. The plant does not like soggy or waterlogged soils.
Cultivation Methods
Astragalus decumbens (Nutt. ex Torr. & Gray) Gray var. oblongifolius (Rydb.) Cronq. is a hardy plant that can grow in various soil types. However, it prefers well-draining soil with a neutral pH level. It thrives in full sun to partial shade and can tolerate hot and dry conditions. It’s best to plant in early spring or fall.
Watering Needs
Astragalus decumbens (Nutt. ex Torr. & Gray) Gray var. oblongifolius (Rydb.) Cronq. needs regular watering until it establishes, but it can tolerate droughty conditions once it matures. It’s best to keep the soil moist but not soggy, as excessive water can result in root rot. Water deeply and less frequently, instead of shallow and frequent watering.
Fertilization
Astragalus decumbens (Nutt. ex Torr. & Gray) Gray var. oblongifolius (Rydb.) Cronq. doesn’t require fertilization, as it can fix its nitrogen. However, if the soil is poor or lacks organic matter, you can add a slow-release fertilizer with a low nitrogen level twice a year. Apply the fertilizer in the spring and fall.
Pruning
Astragalus decumbens (Nutt. ex Torr. & Gray) Gray var. oblongifolius (Rydb.) Cronq. doesn’t need regular pruning, but you can trim the plant to maintain its shape and size. Prune dead or damaged stems as soon as you notice them. To encourage bushier growth, you can pinch the tips of the stems. However, avoid pruning too much, as it can reduce the plant’s vigor and flowering.
Propagation of Astragalus decumbens var. oblongifolius
Propagation of Astragalus decumbens var. oblongifolius can be done through both seed and vegetative methods.
Seed propagation
The seeds of this plant have a hard seed coat and may require scarification or stratification to increase germination rates. Scarification can be done by nicking the seed coat with a knife or rubbing them with sandpaper, while stratification involves exposing the seeds to cold, moist conditions for a period of time. Plant the scarified or stratified seeds in well-draining soil, and keep the soil moist but not waterlogged. Germination may take several weeks to several months.
Vegetative propagation
Astragalus decumbens var. oblongifolius can also be propagated through vegetative methods, such as stem cuttings or division.
Stem cuttings can be taken in the spring or summer and should be about 4-6 inches in length. Remove the lower leaves from the stem and dip the cut end in rooting hormone. Plant the cutting in moist soil and keep it in a humid environment until roots have formed.
Division of established plants can also be done in the spring or fall. Carefully dig up the plant and divide the rootball into sections, ensuring that each section has both roots and shoots. Replant the sections in well-draining soil and water thoroughly.
Disease and Pest Management for Astragalus decumbens var. oblongifolius
Astragalus decumbens var. oblongifolius is a hardy plant, but it can still be susceptible to disease and pest infestations. Being able to identify common pests and diseases that can affect the plant is important to effectively manage them.
Common Diseases
The most common diseases that can affect Astragalus decumbens var. oblongifolius are fungal diseases. Fungal diseases can be caused by damp and humid conditions that promote the growth of fungi. These diseases can appear as spots on the leaves, stem, and flowers or can cause the plant to wither and die.
One fungal disease that can affect the plant is powdery mildew. Powdery mildew appears as a powdery white substance on the leaves and stems of the plant. To manage powdery mildew, removing affected leaves and stems is recommended. Additionally, avoiding overhead watering and providing proper air circulation around the plant can help prevent powdery mildew from developing.
Common Pests
The most common pests that can affect Astragalus decumbens var. oblongifolius are aphids, spider mites, and root-knot nematodes.
Aphids are small insects that feed on the sap of the plant. Affected plants may have yellowed, distorted, or curled leaves. To manage aphids, spraying the plant with water can help wash them away. Additionally, applying insecticidal soap or neem oil can help control their population.
Spider mites are tiny pests that suck the sap of the plant, causing it to turn yellow and become stippled. To manage spider mites, spraying the plant with water to remove them and increasing the humidity around the plant can help prevent their infestation.
Root-knot nematodes are microscopic pests that invade the roots of the plant, causing them to become swollen and forming knots. These infected roots may be stunted and unable to provide the necessary nutrients and water to the plant. To manage root-knot nematodes, removing infected plants and practicing crop rotation can help prevent their infestation.
Overall, paying close attention to the condition of Astragalus decumbens var. oblongifolius can help identify and manage any disease or pest infestation before it becomes too severe and affects the overall health of the plant.
