Origin
Astragalus flexuosus var. diehlii (M.E. Jones) Barneby is a plant that belongs to the Fabaceae family, which is also known as the pea family. It is native to the western United States, particularly in the states of Utah, Arizona, Colorado, New Mexico, and Wyoming.
Common Names
Some of the common names of this plant include Diehl's milkvetch, and Diehl's astragalus.
Uses
The plant Astragalus flexuosus var. diehlii is of great significance as it has potential use in agricultural systems and in medicine. The plant has been reported to increase soil fertility as it is able to fix atmospheric nitrogen. This makes it a valuable crop rotation plant among farmers.
Additionally, it has medicinal properties and has been used for medicinal purposes by different communities for several years. For instance, it has been used by the Navajo tribe to treat several diseases and ailments such as joint pains, fever, coughs, sore throats, and to boost the immune system.
General Appearance
Astragalus flexuosus var. diehlii has a shrub-like appearance and grows up to a height of about 30-70 cm. The stem is woody, with branches that have alternate and compound leaves. The leaves are 2-3 cm long and have 11-15 leaflets. The flowers are pinkish-purple, and they bloom from May to July. The fruits are 1.5-2.5 cm long, and are covered with hair-like structures.
Light Conditions
Astragalus flexuosus var. diehlii requires full sun exposure to grow optimally. The plant needs a minimum of six hours of direct sunlight each day. When grown in shaded areas, the plant's growth is likely to be stunted, and its flowers may not bloom properly.
Temperature Conditions
This species of Astragalus is fast-growing, drought tolerant, and can tolerate a wide range of temperatures. The plant prefers temperatures ranging between 45°F and 85°F, although it can withstand temperatures as low as 32°F. However, prolonged exposure to frost may damage or kill the plant. During the summer, the plant grows best in hot, dry conditions.
Soil Conditions
Astragalus flexuosus var. diehlii thrives in well-draining soils. The ideal soil pH for this plant ranges from 7.0 to 8.0. The plant prefers soils that are rich in organic matter and are moderately fertile. The plant can withstand high levels of salinity but does not perform well in clay soils. When planting, it is essential to ensure that the soil is adequately aerated to prevent waterlogging, which may lead to root rot.
Cultivation Methods
Astragalus flexuosus var. diehlii is a perennial plant that prefers well-drained soil in full sun to partial shade. It can tolerate a wide range of soil types, including clay, sandy, or rocky soils. The plant can be grown from seed or propagated from cuttings. It is important to provide adequate spacing between plants as they can spread up to 2 feet (60 cm) wide.
Watering Needs
Astragalus flexuosus var. diehlii prefers moderate moisture, so water the plants regularly during the growing season. Avoid overwatering, as it can lead to root rot. Allow the soil to dry out slightly between waterings to prevent waterlogging.
Fertilization
During the growing season, feed the plants with a balanced, all-purpose liquid fertilizer once every two to three weeks. Avoid over-fertilization, as it can cause excessive vegetative growth and weaken the plant's overall health.
Pruning
Astragalus flexuosus var. diehlii does not require frequent pruning. However, it is advisable to remove spent flowers and stems to encourage bushier growth and promote the development of new shoots. You can also prune the plant in the early spring to control its size and shape.
Propagation of Astragalus flexuosus var. diehlii
Astragalus flexuosus var. diehlii can be propagated by seeds or cuttings.
Propagation by Seeds
Seeds of Astragalus flexuosus var. diehlii can be sown directly into the soil in late fall or early winter, or they can be started indoors in late winter and transplanted outdoors in the spring. The seeds should be soaked for 24 hours in warm water before planting to soften the seed coat and improve germination rates. The seeds should be sown at a depth of 1/8 inch in well-draining soil and kept moist until germination, which typically takes about 2-4 weeks. After germination, the seedlings should be thinned out to a spacing of 6-12 inches.
Propagation by Cuttings
Astragalus flexuosus var. diehlii can also be propagated by stem cuttings taken from mature plants in the spring or summer. The cuttings should be 4-6 inches long and taken from the tips of the stems. The bottom 1-2 inches of the stem should be stripped of leaves to expose the cambium layer, which will help stimulate root development. The cuttings should be dipped in rooting hormone and inserted into a pot filled with moist, well-draining soil. The pot should be covered with a plastic bag to create a humid environment and placed in a location with bright, indirect light. The cuttings should be kept moist but not waterlogged and should root in about 4-6 weeks. Once the cuttings have rooted, they can be transplanted into the ground or into larger pots.
Disease and Pest Management for Astragalus flexuosus (Hook.) Dougl. ex G. Don var. diehlii (M.E. Jones) Barneby Plant
Astragalus flexuosus (Hook.) Dougl. ex G. Don var. diehlii (M.E. Jones) Barneby plant is susceptible to several diseases and pests. Proper disease and pest management are essential for maintaining plant health and quality. Following are some of the common diseases and pests that might affect the plant and ways to manage them.
Diseases
Fungal Diseases: Fungal diseases like root rot, stem canker, and powdery mildew are prevalent in Astragalus flexuosus plant. To prevent fungal diseases, avoid overwatering the plant and ensure proper drainage. Remove any infected plant parts immediately to avoid the spread of the disease. Fungicides can also be used to control the spread of fungal diseases.
Bacterial Blight: Bacterial blight is a common disease that affects Astragalus flexuosus plant, causing wilting and leaf spotting. To control bacterial blight, remove any infected plant parts immediately. Copper fungicides can also be used as a preventive measure.
Viral Diseases: Viral diseases like mosaic virus and yellow vein virus can cause stunted growth and yellowing of leaves in Astragalus flexuosus plant. Unfortunately, there is no effective cure for viral diseases. Remove any infected plant parts immediately and avoid planting new plants in the same area.
Pests
Aphids: Aphids are common pests that affect Astragalus flexuosus plant and suck sap from the plant's leaves, causing them to shrivel. Spray the plant with insecticidal soap or neem oil to control aphid infestations.
Spider Mites: Spider mites can cause yellowing of leaves and produce a fine webbing on the plant. Increase humidity around the plant and use insecticidal soap or neem oil to control spider mite infestations.
Thrips: Thrips are tiny insects that can cause leaf discoloration and deformation in Astragalus flexuosus plant. Use yellow sticky cards to trap and control thrips. Insecticidal soap or neem oil can also be used.
Regular inspection of the Astragalus flexuosus plant for signs of diseases and pests is crucial for early detection and management. Implementing good cultural practices like proper watering, fertilization, and pruning can also promote plant health. Always read and follow the instructions on the labels of any chemical products used for disease and pest management.
