Origin
Descurainia incana (Bernh. ex Fisch. & C.A. Mey.) Dorn ssp. incana, commonly known as gray tansy mustard or hoary tansy mustard, is a plant species native to North America. It is commonly found throughout California, Arizona, New Mexico, Texas, and Mexico.
Common Names
The common names for Descurainia incana include gray tansy mustard, hoary tansy mustard, mountain tansy mustard, and gray poverty weed.
Uses
Descurainia incana has been used for medicinal purposes by different Native American tribes. The Seri tribe of Mexico used the plant to treat asthma and other respiratory ailments, while the Navajo and Pima tribes used an infusion of the plant to treat headaches, fevers, and colds.
Descurainia incana is also used in the production of yellow dyes, and its seeds are used as a condiment or spice, adding flavor to dishes.
General Appearance
Descurainia incana is a small annual plant that grows up to 30 cm in height. The plant has branching, erect stems and greyish-green leaves that are pinnately divided into narrow segments. The flowers of the plant are small and yellow, arranged in racemes at the end of the branches. The fruit of Descurainia incana is a long, narrow pod that contains small, elliptical seeds.
The plant is adapted to arid conditions and grows in a range of habitats, including desert washes, sagebrush scrub, and pinyon-juniper woodlands.
Light Requirements
The plant Descurainia incana (Bernh. ex Fisch. & C.A. Mey.) Dorn ssp. incana typically thrives in full sunlight to partial shade. It is considered a sun-loving plant but can tolerate some shade, particularly during the hottest part of the day. Therefore, it is advisable to grow this plant in a location where it gets plenty of direct sunlight in the morning and late afternoon but enjoys some shade during the hottest time of the day.
Temperature Requirements
Descurainia incana (Bernh. ex Fisch. & C.A. Mey.) Dorn ssp. incana is a hardy plant that can grow in different temperature ranges. It is classified as a cool-season biennial and can withstand temperatures as low as -15 °C. However, it thrives in a temperature between 12-25 °C. Therefore, it is best to grow this plant during spring and fall when the temperature is mild.
Soil Requirements
The plant Descurainia incana (Bernh. ex Fisch. & C.A. Mey.) Dorn ssp. incana prefers a well-drained soil that is sandy, loamy, or clay with a pH range of 6-8. The soil should be rich in organic matter and nutrients such as nitrogen, phosphorus, and potassium. It is best to amend the soil with compost or other organic matter before planting.
Cultivation Methods
Descurainia incana grows well in areas with full sun exposure and well-draining soil. It thrives in regions with dry to semi-dry climates. The plant requires warm to hot temperatures, and it can tolerate mild frost.
It is possible to grow Descurainia incana from seeds or cuttings, but propagated plantings can produce more vigorous plants. Germination from seeds takes about two to three weeks. For cuttings, ensure the stem is about four inches long and has four to six leaves at the top.
The plant should be spaced around 12 inches apart to provide enough room for the plant to grow.
Watering Needs
Descurainia incana does not need much watering, and it is drought-tolerant. Overwatering can lead to the plant being susceptible to fungal diseases. The plant should be watered when the soil around it is dry to the touch.
Mulching is helpful in retaining soil moisture, but ensure the mulch is not in direct contact with the stem as it can attract pests and lead to rotting.
Fertilization
The plant does not require frequent fertilization. A light application of a balanced fertilizer will be sufficient once a year during the growing season.
Before applying the fertilizer, ensure the soil is moist. Avoid applying the fertilizer directly to the leaves as it can scorch them.
Pruning
Pruning is not a necessary requirement for Descurainia incana. However, if necessary, pruning should be done in late fall or early spring before the flowers emerge.
Deadheading is beneficial in promoting the growth of more flowers. It also prevents the plant from self-seeding and becoming invasive.
Propagation of Descurainia incana
Descurainia incana is a species of flowering plant that belongs to the family Brassicaceae. It is a hardy plant that is known for its weedy nature. Descurainia incana propagates through various methods:
By seeds
Seeds are the most common method of propagation for Descurainia incana. Seeds can be collected from mature plants and sown directly in the soil during the fall season. It is important to ensure that the soil is well-drained, moist and receives plenty of sunlight for successful germination. The seeds will germinate in the following spring season.
By cuttings
Propagation through cuttings is not very common for Descurainia incana. However, it is still a viable method that can be used to propagate the plant. Cuttings should be taken in the spring season from new growth. Rooting hormones can be used to help the cutting establish roots. Cuttings should be planted in well-drained soil, kept moist, and placed in a position where they receive plenty of sunlight.
By division
Propagation through division is not very common for Descurainia incana as the plant produces a taproot that can be difficult to divide. However, if division is necessary, it should be done during the fall season when the plant is dormant. The taproot should be carefully dug up and divided into smaller segments. The new segments should then be replanted into well-drained soil and kept moist for successful growth.
Disease Management
Descurainia incana is generally resistant to many diseases, but it is still susceptible to a few. The most common diseases that can affect the plant include:
- Root Rot: This disease is caused by various species of fungi that live in the soil. The symptoms of root rot include wilting, yellowing leaves, and stunted growth. To manage root rot, remove any infected plants, avoid overwatering and provide good drainage. Also, avoid replanting in the same area where the infection occurred as the fungal spores can persist in the soil.
- Mildew: Mildew is caused by a fungus that grows on the leaves of the plant and appears as a powdery white film. To manage mildew, remove any infected leaves and avoid wetting the leaves during watering. It's also advisable to improve air circulation around the plants by reducing overcrowding and allowing sufficient spacing between plants.
Pest Management
Descurainia incana is also susceptible to a few pests which include:
- Aphids: These small insects suck the sap of the plant which can lead to yellowing, stunted growth and curled leaves. To manage them, introduce natural predators and insecticidal soaps. Also, avoid over-fertilizing the plants as the high nitrogen content can attract aphids.
- Cabbage worm: These pests are a type of caterpillar that can severely damage the leaves of the plant and can also lead to the spread of diseases. To manage them, handpick and remove the caterpillars manually, plant intercropping plants that attract their natural predators such as birds. It's also advisable to use row covers to protect the plants from their infestation.
