Overview: Lupinus microcarpus Sims var. horizontalis (Heller) Jepson
Lupinus microcarpus Sims var. horizontalis (Heller) Jepson is a perennial herbaceous plant that belongs to the Fabaceae family. It is commonly known as Chamise Lupine, Small-fruited Lupine, and Pacific Lupine.
Origin and Distribution
Lupinus microcarpus Sims var. horizontalis (Heller) Jepson is native to California, United States, and is widely distributed throughout the state. It is also found in Baja California, Mexico, and Oregon.
Appearance
Lupinus microcarpus Sims var. horizontalis (Heller) Jepson typically grows up to 40 cm tall and 60 cm wide. The stem is slender and green, and the leaves are palmately compound with 5-9 leaflets. The leaflets are lanceolate to elliptic in shape and are 1-2.5 cm long and 0.3-1 cm wide. The inflorescence is a tall and conical spike that ranges from 5-15 cm long. The flower color varies from purple, blue, to white, with the upper banner petal covered in fine hairs. The fruit is a small and hairy pod, measuring 1-1.5 cm long and 0.6-0.8 cm wide, containing small seeds that are important for its propagation.
Uses
Lupinus microcarpus Sims var. horizontalis (Heller) Jepson has a wide range of uses. It is used as a food source for livestock due to its high protein content. Native Americans used to eat the seeds roasted or boiled. It is also used as an ornamental plant in gardens, landscaping, and restoration projects due to its beautiful flowers and overall appearance. Additionally, it is an important plant for soil stabilization and erosion control thanks to its deep-rooting system that can fix nitrogen in the soil.
Light Requirements
Lupinus microcarpus Sims var. horizontalis requires full sun exposure to grow. It needs at least six hours of direct sunlight daily. The plant will not thrive or blossom fully in shady conditions.
Temperature Requirements
Lupinus microcarpus Sims var. horizontalis thrives in warm and dry conditions. The plant grows well in USDA Hardiness Zones 8-10. The ideal daytime temperature for the plant ranges from 60-85°F. Nighttime temperatures should be around 50-60°F.
Soil Requirements
Lupinus microcarpus Sims var. horizontalis grows optimally in well-drained soil. The plant does not thrive in water-logged soil as it can cause root-rot disease. The soil should have a neutral to slightly acidic pH of 6.1-7.8. The plant does well in sandy, loamy, and clay soils.
Cultivation Methods
Lupinus microcarpus Sims var. horizontalis (Heller) Jepson is a species of lupine that is native to California. It is a hardy plant that is easy to grow and does best in well-draining soil with a pH range between 6.4 and 7.2. It thrives in sunny to partially shaded locations and prefers an area with good air circulation.
It can be grown from seed or from cuttings, and should be planted in the spring or fall. When planting from seed, the soil should be lightly moistened beforehand and the seeds should be covered with no more than 1/8 inch of soil. When planting from cuttings, the cuttings should be taken in the spring and planted right away in a well-draining soil mix.
Watering Needs
Lupinus microcarpus Sims var. horizontalis (Heller) Jepson requires moderate watering, and should be watered deeply once a week during the growing season. The plant is drought-tolerant once it is established, but it is important to keep the soil from completely drying out. Overwatering can cause root rot, so make sure the soil has good drainage and do not allow the soil to remain waterlogged.
Fertilization
The best time to fertilize Lupinus microcarpus Sims var. horizontalis (Heller) Jepson is in the spring, just before the growing season starts. A balanced fertilizer with an N-P-K ratio of 8-8-8 or 10-10-10 is recommended, applied according to the instructions on the package. Too much fertilizer can cause the plant to produce more foliage than flowers, so be careful not to over-fertilize.
Pruning
Lupinus microcarpus Sims var. horizontalis (Heller) Jepson does not require much pruning, but it can be helpful to deadhead spent blossoms to prevent the plant from putting energy into seed production. To deadhead, simply remove the spent flower spike by pinching it off just above the basal foliage. Regular pruning is not recommended, as it can lead to a reduction in flower production and may weaken the plant.
Propagation of Lupinus microcarpus Sims var. horizontalis (Heller) Jepson
Lupinus microcarpus Sims var. horizontalis (Heller) Jepson, commonly known as the arroyo lupine, can be propagated through various methods including seed propagation, cutting propagation, and division.
Seed Propagation
Seed propagation is the most common and effective method of propagating Lupinus microcarpus. The seeds should be collected from healthy, mature plants during the autumn season when the pods are dry.
The seeds should be scarified or nicked at their tough exterior to speed up the germination process, then soaked in water for 24 hours before planting. Plant the seeds directly outside in a well-drained soil that receives full sunlight. Germination should occur within 15-30 days.
Cutting Propagation
Cutting propagation is another method that can be used to propagate Lupinus microcarpus. Select a healthy and mature plant and remove a stem piece with a sharp and sterilized gardening tool.
Remove all the lower leaves from the cutting and apply rooting hormone to the cut end. Place the cutting in a well-draining potting mix and water it regularly. Keep it in a warm and humid area until new growth appears, which indicates that rooting has occurred.
Division Propagation
Division propagation can also be used for Lupinus microcarpus when the plant has become too large and needs to be divided to promote healthy growth.
The plant should be carefully removed from the soil and the root ball should be divided into smaller portions using a sterilized garden tool. Each division should have a sufficient number of shoots and roots.
The divisions should be planted in well-draining soil that receives sufficient sunlight. Water them regularly and keep them in a warm and humid area until new growth appears above the soil.
Disease Management
Lupinus microcarpus Sims var. horizontalis (Heller) Jepson, commonly known as chaparral lupine, is a hardy plant that is relatively resistant to diseases. However, there are a few common diseases that can still affect this plant.
One of the most common diseases that affect chaparral lupine is powdery mildew. Powdery mildew is a fungal disease that forms a white, powdery coating on the leaves, stems, and flowers of the plant. To manage powdery mildew, it is important to practice good sanitation by removing and destroying any infected plant debris. Additionally, you can use fungicide sprays to help manage the disease.
Another disease that affects chaparral lupine is leaf spot. Leaf spot is a fungal disease that causes circular or angular brown spots on the leaves of the plant. To manage leaf spot, you should remove infected leaves and destroy them. Additionally, you can use fungicide sprays to help manage the disease.
Pest Management
Chaparral lupine is also relatively resistant to pests. However, there are a few common pests that can still affect this plant.
One of the most common pests that affect chaparral lupine is aphids. Aphids are small insects that suck the sap from the leaves and stems of the plant. To manage aphids, you can use insecticidal soaps or neem oil. Additionally, you can encourage natural predators of aphids, such as ladybugs, to help manage the pest.
Another pest that affects chaparral lupine is spider mites. Spider mites are tiny insects that feed on the sap of the plant and can cause leaves to turn yellow or bronze. To manage spider mites, you can use insecticidal soaps or neem oil. Additionally, you can increase humidity around the plant to discourage spider mites from infesting it.
