Overview
Lasthenia macrantha (Gray) Greene ssp. prisca Ornduff, commonly known as yellow ray goldfields, is a herbaceous perennial plant species that is a member of the sunflower family (Asteraceae). This species is native to coastal California, specifically along the western edge of the Central Valley and the western slope of the Sierra Nevada Mountains.
Common Names
Yellow ray goldfields is the most common name for Lasthenia macrantha (Gray) Greene ssp. prisca Ornduff. Other common names for this plant species include giant goldfields and large-flowered goldfields.
Appearance
Yellow ray goldfields typically grow to a height of 20-50 cm and have somewhat cylindrical flowers that can be yellow or orange. This plant species typically blooms in late March to early May. The leaves of yellow ray goldfields are light green and smooth with jagged edges, with an oblong to spatulate shape.
Uses
Lasthenia macrantha (Gray) Greene ssp. prisca Ornduff is commonly used as an ornamental plant by gardeners due to its attractive flowers. Historically, indigenous communities in coastal California used the seeds as a food source and made a tea from the leaves that was believed to have medicinal properties.
Light Requirements
The Lasthenia macrantha ssp. prisca plant prefers to grow in full sun or partial shade. It requires at least 6 hours of direct sunlight per day to thrive.
Temperature Requirements
The plant is adapted to the Mediterranean climate, which is characterized by hot and dry summers and cool, wet winters. It can tolerate temperatures up to 90°F (32°C) during the day and 50°F (10°C) during the night.
Soil Requirements
The Lasthenia macrantha ssp. prisca plant prefers well-drained soils of medium texture. It can tolerate a wide range of soil pH, from 5.8 to 8.0. The plant is adapted to soils with low to moderate fertility and can survive in nutrient-poor soils.
Cultivation
Lasthenia macrantha (Gray) Greene ssp. prisca Ornduff, commonly known as the coastal tarplant, is native to California's coastal ranges, where it grows in sandy soil near the coast. Therefore, its preferred growing conditions involve a temperate climate with well-drained, sandy soil. It can tolerate partial shade, but it grows best in full sun.
Watering
This plant is drought-tolerant and can handle periods of low rainfall. It prefers moderate watering during the growth period when the soil is dry to the touch, which can be once a week or once in two weeks. However, during the winter months, it needs minimal to no watering as the plant goes dormant. Overwatering can lead to root rot and harm the plant's growth.
Fertilization
Lasthenia macrantha does not need frequent fertilization as it is a light feeder. However, an initial application of a balanced fertilizer at the beginning of the growth period can improve plant growth and flowering. Too much fertilizer can cause excessive nutrient uptake and result in poor-quality flowers.
Pruning
This plant does not require pruning frequently, but deadheading spent blooms can help prolong flowering. Deadheading is the method of removing wilted flowers to allow the plant to put its energy into producing new buds and blooms. After the growth period, the plant dies down to the ground, and pruning is not necessary.
Propagation of Lasthenia macrantha ssp. prisca
Lasthenia macrantha ssp. prisca Ornduff, commonly known as the San Francisco Tidy-tips, can be propagated by both seeds and cuttings.
Seed Propagation
Seed propagation is the most common method used to propagate Lasthenia macrantha ssp. prisca. The seeds are typically sown in the fall or winter in areas with mild climates. Before sowing the seeds, the soil should be loosened and amended with compost to improve drainage. The seeds should be spaced 6-12 inches apart and covered with a thin layer of soil. Water the soil immediately after sowing and keep it moist until the seeds germinate, which usually takes about 10-14 days. Once the seedlings have developed their second pair of leaves, they can be thinned to the desired spacing.
Cutting Propagation
Lasthenia macrantha ssp. prisca can also be propagated using cuttings. Cuttings should be taken in the spring or summer, when the plant is actively growing. Select a stem that has not yet flowered and make a clean cut just below a node. Remove the lower leaves and cut the remaining leaves in half. Dip the base of the cutting in rooting hormone and plant it in a pot filled with a well-draining potting mix. Water the pot immediately after planting and keep the soil moist until the cutting has established roots and starts to grow new leaves. Once the cutting is well established, it can be transplanted to a larger pot or directly into the garden.
Disease Management
Lasthenia macrantha (Gray) Greene ssp. prisca Ornduff is a relatively low-maintenance plant, but it is not immune to diseases. Here are some common diseases that might affect the plant and ways to manage them:
- Powdery mildew: This is a fungal disease that often appears as a white, powdery coating on the leaves. To manage it, remove the infected leaves and debris from around the plant. Use a fungicide if necessary.
- Rust: Rust appears as orange or yellow spots on leaves and stems. Managing it involves similar steps to powdery mildew: remove infected material and use fungicide if necessary. Make sure to properly dispose of any infected material to prevent the spread of the disease.
- Pythium root rot: This is a soil-borne disease that can cause the plant to wilt and die. To management it, avoid overwatering the plant as this can promote the growth of the pathogen. Use a fungicide if necessary.
Pest Management
In addition to diseases, pests can also affect Lasthenia macrantha (Gray) Greene ssp. prisca Ornduff:
- Aphids: These tiny insects suck sap from the plant, causing leaves to wilt and curl. To manage them, use insecticidal soap or neem oil. Encouraging natural predators like ladybugs and lacewings can also be effective.
- Spider mites: These are tiny, spider-like insects that suck sap from the plant, causing brown spots and yellowing leaves. Managing them involves a similar approach to aphids: use insecticidal soap or neem oil and encourage natural predators.
- Snails and slugs: These pests can eat away at the leaves and stems of the plant. To manage them, remove any hiding places like piles of leaves or debris around the plant. Use traps or baits, such as beer traps, to attract and kill the pests.
Keep in mind that preventing pests and diseases starts with healthy plants. Make sure the Lasthenia macrantha (Gray) Greene ssp. prisca Ornduff is growing in the right conditions, with well-draining soil and proper sunlight. Keep the plant clean and free of debris, and avoid overcrowding. With these measures, your plant should remain healthy and strong.
