Origin and Common Names
Lasthenia macrantha (Gray) Greene ssp. macrantha, commonly known as large flowered goldfields, is a species of flowering plant that belongs to the Asteraceae family. This plant is endemic to California, where it can be found in the Sierra Nevada foothills and the Coast Ranges.
General Appearance
This annual plant grows up to 20 centimeters in height and can spread up to 30 centimeters wide. Lasthenia macrantha has slender, branching stems that are covered with narrow, linear leaves that range from 2 to 8 centimeters in length. The plant is covered in glandular hairs, which produce a strong scent when rubbed.
Lasthenia macrantha flowers from March to July, producing clusters of up to 20 bright yellow flower heads. The flowers measure around 2.5 centimeters in diameter and have ray and disk florets. The plant produces seeds that can germinate easily with the first heavy rain of autumn.
Uses
Lasthenia macrantha is a popular plant in wildflower gardens and can also be grown in large containers. Its bright yellow flowers attract butterflies and other pollinators. Additionally, Native Americans used the leaves of the plant to make tea to alleviate stomachache and the seed pods were eaten fresh or dried for winter consumption.
Light Requirements
Lasthenia macrantha subspecies macrantha prefers full sunlight exposure for optimal growth. It is adapted to habitats with direct sunlight and warmth, making it a sun-loving plant. In areas with low light conditions, the plant's stem elongation and overall growth will reduce. Therefore, it's recommended to grow this plant in direct sunlight.
Temperature Requirements
The plant thrives in warm temperatures ranging from 16°C to 30°C. During the warmer months, it can tolerate higher temperatures. However, the plant is intolerant to frost, and exposure to cold temperatures can significantly affect its growth. Damaged leaves and slowed growth are some of the visible effects of exposure to low temperatures. It's recommended to protect the plant from frost to maintain optimal growth and performance.
Soil Requirements
The species is adaptable to various soil conditions, but it thrives in well-drained soils with a neutral pH between 6.5 and 7.5. The soil should also be rich in organic matter to provide the plant with essential nutrients. A soil test can help determine the specific nutrient requirements of the plant. In regions with high clay content, adding sand and compost can help improve soil drainage and structure. This plant is also moderately drought-tolerant once established but prefers regular watering intervals to avoid a water deficit.
Cultivation Methods of Lasthenia Macrantha (Gray) Greene ssp. Macrantha
Lasthenia macrantha (Gray) Greene ssp. macrantha is a relatively easy plant to grow and cultivate. It is an annual herb that prefers well-drained soils and areas with full sun exposure. The plant can grow from seed, and the best time to plant the seeds is in the early spring. Before planting, the soil must be tilled to loosen it up and remove any remaining weeds. Once planted, the seeds should be covered with a thin layer of soil and watered regularly.
Watering Needs of Lasthenia Macrantha (Gray) Greene ssp. Macrantha
Lasthenia macrantha requires moderate watering, and the soil should be kept moist but not waterlogged. The plant should be watered once a week, but the frequency may vary based on climate and soil conditions. If the plant is grown in containers, it may require more frequent watering, as the soil in containers tends to dry up quicker than planted directly in the soil. Watering should be done in the morning or evening hours when the sun is less intense.
Fertilization of Lasthenia Macrantha (Gray) Greene ssp. Macrantha
Lasthenia macrantha is not a heavy feeder and may not require regular fertilization. However, if the plant appears to have stunted growth or pale-yellow leaves, a light application of a general-purpose fertilizer can be added during the growing season. Fertilization should be done sparingly to prevent over-fertilization, which can damage the plant.
Pruning of Lasthenia Macrantha (Gray) Greene ssp. Macrantha
Pruning of Lasthenia macrantha is not a common practice, and the plant usually requires very little maintenance. However, if the plant becomes leggy or bushy, pinching back some of the stems can promote fuller, more compact growth. Deadheading the spent flowers can also extend the blooming period of the plant.
Propagation of Lasthenia macrantha (Gray) Greene ssp. macrantha
Lasthenia macrantha (Gray) Greene ssp. macrantha or commonly known as large-flowered goldfields plant, is a perennial herb that produces bright yellow flowers during spring. Propagation of this plant can be achieved through four different methods:
1. Seed propagation
Seed propagation is the most common method used to propagate Lasthenia macrantha. The seeds can be collected from the plant during the summer and fall months when the seed pods have turned brown and dry. The seeds should be cleaned and stored in a cool, dry place until the following spring. Early spring is the best time to sow the seeds, either by directly sowing them into the desired area or starting them indoors. The seeds should be planted in well-draining soil and kept moist until they germinate.
2. Division
Division is another method of propagating Lasthenia macrantha. This method is best done in the early spring before new growth starts. The plant should be carefully dug up and the plant’s clump separated into sections. Each section should contain a sufficient number of roots and stems. The clumps can be replanted in the desired area.
3. Root cuttings
Lasthenia macrantha roots can also be used to propagate the plant. Root cuttings can be taken in late fall or early winter when the plant is dormant. Choose healthy roots and cut them into 2- to 3-inch sections. These sections should be placed horizontally in a well-draining potting mix with half of the section buried. Place the container in a cool, shaded area where it can be kept moist. Roots will grow from the buried section, and new shoots will emerge from the upper section.
4. Stem cuttings
Propagation through stem cuttings is possible, but it is not as commonly used as the previous three methods. It is best done during the summer months when the plant is actively growing. Cut a 3- to 4-inch section of the plant's stem below the node and remove the leaves from the bottom half of the cutting. Dip the end of the cutting in rooting hormone, then plant it in well-draining soil. Keep the soil moist and place the cutting in a warm, shaded area. Roots will develop within a few weeks, and the cutting can be transplanted after 8-12 weeks.
Disease Management
Lasthenia macrantha (Gray) Greene ssp. macrantha is susceptible to certain diseases. The most common diseases that can affect the plant are powdery mildew, root rot, and leaf spot. Powdery mildew is a fungal disease that appears as white, powdery spots on the leaves, stems, and flowers. Root rot is another fungal disease that occurs when the soil is constantly wet, leading to the roots' decay. Leaf spot is also a fungal disease that causes the leaves to have spots, which eventually turn yellow or brown.
To manage these diseases, the following practices are recommended:
- Plant in well-draining soil to prevent root rot
- Water the plant only when necessary
- Prune out infected leaves and stems
- Apply a fungicide to the plant
Pest Management
In addition to diseases, Lasthenia macrantha (Gray) Greene ssp. macrantha can also be affected by pests. The most common pests that attack the plant are aphids, spider mites, and thrips. Aphids are tiny, pear-shaped insects that suck sap from the plant, leaving behind a sticky residue. Spider mites are very small, but they can cause significant damage by sucking the plant's sap and leaving behind yellow or brown spots on the leaves. Thrips are also small insects that suck sap from the flower buds and cause them to deform.
To manage these pests, the following practices are recommended:
- Use an insecticidal spray on the plant
- Introduce natural predators, such as ladybugs or lacewings
- Prune out heavily infested leaves and stems
- Maintain proper hygiene by cleaning up fallen leaves and flowers
