Overview
Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. is a flowering plant in the legume family, Fabaceae. It is native to western North America and is commonly found in the United States and Mexico. The plant is known for its striking appearance and has several uses.
Common Names
The plant is commonly known as Sierra Lupine, Tailcup Lupine, Redstem Lupine, and Bicolored Lupine.
Appearance
Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. is a herbaceous perennial plant that grows up to 1 meter tall. The plant has upright stems that are covered in fine hairs and are reddish-brown in color. The leaves are alternate, palmately compound, with 5-9 leaflets that are bluish-green in color and covered in fine hairs. The inflorescence is a spike of pink or purple pea-shaped flowers that blooms from May to July. The fruit is a hairy pod that contains several seeds.
Uses
The plant has several uses. The seeds are edible and were traditionally used as food by the Indigenous people of North America. The plant is used in the medicine field to treat skin problems. The plant is also used for decorative purposes due to its striking appearance.
Light Requirements
Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. typically grows best in full sun to partial shade conditions. It is a sturdy plant and can handle strong sunlight, especially if it is provided with enough water. If grown in partial shade, it is important to ensure that it receives at least 4-6 hours of direct sunlight daily.
Temperature Requirements
Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. can tolerate a range of temperatures, but it prefers moderate temperatures ranging from 15-25°C. It is a cool weather plant and hence requires cool temperatures for successful growth. However, it can also tolerate frost which makes it adaptable to different areas. If the temperature rises above 30°C for a prolonged period, the plant will start to wilt, and its growth rate will slow down.
Soil Requirements
The soil requirements for Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. are quite flexible. However, it prefers well-drained, fertile soils. The plant can also grow in sandy or rocky soils but may require frequent watering. It is important to ensure the soil pH remains neutral, between 6.0 and 7.5. If the soil is acidic, then it may be necessary to add calcium and magnesium to neutralize the pH. The plant requires moderate water levels and grows best in areas where annual rainfall is between 500 to 1000 mm.
Cultivation Methods
Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. is a hardy, drought-tolerant plant that can grow in a variety of soil types. However, it does require well-draining soil to prevent root rot. It grows best in full sun to partial shade and can grow up to 3 feet tall.
Sow seeds outside in early spring after the soil has begun to warm up. Place the seeds about 1 inch deep and 3 inches apart. If starting indoors, start seeds in February and transplant outdoors after the last frost. Thin seedlings to about 12 inches apart once they are a few inches tall.
Watering Needs
Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. requires regular water but can tolerate some periods of drought. Water the plant deeply once a week during the growing season. Avoid overwatering as this can lead to root rot.
Water the base of the plant to prevent water from getting on the leaves, which can cause disease.
Fertilization
Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. does not require regular fertilization but can benefit from a balanced, slow-release fertilizer at the beginning of the growing season.
Avoid fertilizing too much or with high-nitrogen fertilizers as this can cause too much foliage growth and fewer flowers.
Pruning
Prune Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. after it finishes flowering to encourage a neat appearance and to prevent reseeding. Cut back the entire plant to about 6 inches above ground level.
If you want to encourage reseeding, allow some flower stalks to remain on the plant and drop seeds naturally.
Propagation of Lupinus caudatus var. rubricaulis
Propagation of Lupinus caudatus var. rubricaulis is usually done through seeds. The plant is an annual, so seeds should be sown every year to ensure a constant supply.
Collecting Seeds
Seeds of Lupinus caudatus var. rubricaulis can be collected after the pods have turned brown and are beginning to open. The pods should be carefully removed and dried. Once dry, the seeds can be removed from the pods and stored in a cool, dry place until they are ready to be sown.
Sowing Seeds
Seeds should be sown in a well-draining soil mix after the last frost. The soil should be kept moist but not wet. The seeds can be lightly covered with soil, but they require sunlight to germinate so the covering should be minimal.
Care After Germination
Once the seeds have germinated, they should be thinned to allow for adequate spacing. The seedlings should receive plenty of sunlight and water to encourage their growth. After they have reached a suitable size and are strong enough, they can be transplanted into their final growing location.
Disease and Pest Management for Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm.
Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. is generally a healthy plant, but it may suffer from disease and pest attacks. Here are some of the common diseases and pests that may infect or infest the plant and suggestions on how to manage them:
Diseases
Bacterial blight: This is a bacterial disease that causes water-soaked lesions on the leaves and stems of the plant. The infected parts may eventually turn yellow or brown and die. To manage this disease, ensure you plant healthy seedlings and space them appropriately. Avoid overhead watering, and prune infected parts of the plant. In severe cases, a copper-based fungicide may be used.
Fungal leaf spot: This is a common fungal disease that causes small, circular, water-soaked spots on the leaves. The spots may eventually enlarge and coalesce, leading to premature defoliation. The disease is favored by warm and wet conditions. To manage this disease, ensure adequate air circulation and avoid overhead watering. Prune infected parts of the plant and dispose of them properly. A copper-based fungicide may also be used.
Pests
Aphids: Aphids are small, soft-bodied insects that suck the sap from the plant, causing leaf curling, yellowing and stunted growth. To manage these pests, use a strong spray of water to dislodge them or use insecticidal soap or neem oil.
Spider mites: Spider mites are tiny pests that suck the sap from the plant, causing leaves to turn yellow or brown and eventually die. They are favored by dry conditions. To manage these pests, ensure adequate moisture and humidity around the plant by misting. Use a strong spray of water to dislodge them or use insecticidal soap or neem oil.
Leafhoppers: Leafhoppers are small, wedge-shaped insects that suck the sap from the plant, causing yellowing and stunted growth. To manage these pests, use a strong spray of water to dislodge them or use insecticidal soap or neem oil.
Final Thoughts
Your Lupinus caudatus Kellogg var. rubricaulis (Greene) C.P. Sm. plant will generally thrive if you give it proper care and attention. Monitoring for signs of disease and pests regularly, ensuring adequate air circulation, spacing and watering, and pruning infected parts can go a long way in managing these issues. Adopting natural pest and disease control methods like using insecticidal soaps, neem oil, and other organic pesticides is also recommended for effective management.
