Overview
Delphinium viridescens Leib., commonly known as Greenflower Larkspur, is a perennial flowering plant that is native to the mountain ranges of California and Oregon in the United States. This plant is a member of the genus Delphinium, which belongs to the buttercup family Ranunculaceae. Delphinium species are popular garden plants, well-known for their tall spikes of showy flowers that come in different colors. Greenflower Larkspur is one of the few species of Delphinium that produce greenish-yellow flowers.
Description
The stem of Delphinium viridescens is slender and can grow up to 3 feet tall. The plant has palmately divided leaves that are deep green in color and about 2-5 inches in diameter. The leaves are lobed, with each lobe being deeply divided into narrow, pointed segments. The plant produces a spike of flowers that can have between 10 to 30 buds. Each flower is about an inch wide and tubular in shape, with five petal-like sepals that are greenish-yellow in color. The plant blooms in early to mid-summer, from May to July.
Uses
Delphinium viridescens is mainly grown as an ornamental plant in gardens. It is suitable for use in borders, cottage gardens, and wildflower gardens. The plant's tall spikes of yellow-green flowers add height and texture to garden designs, making it an attractive choice for floral arrangements. Greenflower Larkspur thrives in full to partial sun in moist, well-drained soil. It is also known to attract butterflies and hummingbirds.
However, it is important to note that all parts of the Delphinium plant, including the roots, seeds, and leaves, are toxic to humans and animals if ingested. The plant contains a toxic alkaloid called delphinine that can cause symptoms such as nausea, vomiting, and convulsions. Therefore, it is essential to handle the plant with gloves and keep it away from children and pets.
Conclusion
In conclusion, Delphinium viridescens Leib., or Greenflower Larkspur, is a unique and attractive perennial plant that is best grown for ornamental purposes in gardens. The plant has tall spikes of greenish-yellow flowers that bloom in mid-summer and is suitable for use in borders and cottage gardens. However, due to the plant's toxic nature, it is important to handle it with care and keep it away from children and animals.
Light Requirements
Delphinium viridescens Leib. prefers full sun to partial shade. It thrives in areas with a lot of sunlight exposure, especially in the morning hours. Plants growing in partial shade tend to have shorter stems and smaller flowers than those grown in full sun, making them less attractive.
Temperature Requirements
The ideal temperature range for Delphinium viridescens Leib. growth is between 15 to 24°C. While these plants can tolerate a wide range of temperatures, they require consistent temperatures for healthy growth. High temperatures during the flowering season can cause premature flowering and short-lived flowers. Up to 8°C, the plant can tolerate the temperature drop for a short period of time.
Soil Requirements
The plant prefers well-drained soil that is rich in nutrients. The soil pH should be slightly acidic to neutral. Delphinium viridescens Leib. grows best in soil with a pH range of 6.5-7.5. It is important to ensure that the soil is not waterlogged, as this can lead to root rot. Amending the soil with organic matter such as compost or well-rotted manure can help improve soil fertility and drainage.
Cultivation Methods for Delphinium Viridescens Leib.
Delphinium viridescens Leib, commonly known as Green-flowered Larkspur, can be grown as perennials in USDA hardiness zones 4 to 7. They are best propagated through seeds and, when planting, they prefer well-drained, moist soil that is slightly acidic.
Watering Needs for Delphinium Viridescens Leib.
Proper watering is essential to the healthy growth of Green-flowered Larkspur. Regular watering ensures they do not dry out and wither. However, they are also susceptible to standing water, which leads to root rot. Therefore, it is essential to maintain a balance between under and over-watering. Experts recommend watering the plants to a depth of an inch a week.
Fertilization of Delphinium Viridescens Leib.
Delphinium viridescens Leib. requires fertilization to thrive. Use a balanced 10-10-10 fertilizer during the initial growth period in the spring. As the plants develop, feed them with a balanced 5-10-10 fertilizer, applied every two weeks until they have stopped flowering. Over-fertilization is equally dangerous; it results in leggy growth and fewer flowers.
Pruning of Delphinium Viridescens Leib.
Trimming back the spent flower spikes on Green-flowered Larkspur promotes more blooms and cleaner foliage. Cut down the spent spikes entirely to the base, just above the basal foliage, using pruning shears. There is no need to prune back the entire plant during the growing season. However, after the flowers are gone, the foliage may look unattractive, and at this point, the plants can be pruned down to the basal foliage.
Propagation of Delphinium viridescens Leib.
Delphinium viridescens Leib. is a herbaceous perennial plant that can be propagated by different methods. These propagation methods include:
Seed Propagation
Propagation through seeds is the most common method of propagating Delphinium viridescens. The seeds can be sown indoors in early spring or directly in the garden once the weather warms up. The ideal temperature for the germination of these seeds ranges from 60 to 68°F. The seeds should be sown at a depth of about 1/8 inch and should be kept moist until they germinate, which usually takes 10 to 21 days. The seedlings can be transplanted outdoors when they are big enough to handle.
Division Propagation
Another method of propagating Delphinium viridescens is through division. The best time to divide this plant is in the spring or fall. The rootball should be carefully removed from the soil, and the plant should be divided into smaller sections. Each section should have a good root system and a healthy shoot. The sections can then be planted in their new location.
Stem Cutting Propagation
Propagation of Delphinium viridescens through stem cutting is possible but challenging. The best time to take stem cuttings is in the late spring or early summer. The cuttings should be taken from healthy plants, and each cutting should have at least one node. The cuttings should be dipped into a rooting hormone before planting them in moist soil. The pot should be kept covered with a plastic bag or a dome until the cutting has developed roots. Once the cutting has roots, it can be transplanted into its permanent location.
In conclusion, Delphinium viridescens Leib. can be propagated through seeds, division, or stem cuttings. Each method has its own benefits and challenges, so it is up to the gardener to decide which method they prefer to use.
Disease Management for Delphinium viridescens Leib.
Delphinium viridescens Leib. is susceptible to a variety of diseases that can weaken or kill the plant if not managed. Here are some common diseases that might affect Delphinium viridescens Leib. along with ways to manage them:
Leaf spot diseases
Leaf spot diseases are fungal diseases that cause circular or irregular-shaped lesions on the leaves. They may be brown, gray, or black and have a yellow halo. To manage leaf spot diseases, remove infected leaves and destroy them, do not let the infected leaves remain on the soil below the plant. Avoid overwatering, as moist conditions encourage the growth and spread of these diseases. Apply fungicides according to the manufacturer's instructions.
Crown rot
Crown rot is a fungal disease that infects the base of the stem, where it meets the soil. It can cause the plant to wilt and die. To manage crown rot, remove infected plants promptly and avoid planting Delphinium viridescens Leib. in soil that has been previously contaminated with fungal pathogens. Avoid overwatering and ensure good drainage in the planting area.
Virus diseases
Virus diseases can cause stunted growth, yellowing of the leaves, and distorted growth. There are no known cures for viral infections, so the best way to manage them is prevention through good cultural practices. Remove infected plants promptly and dispose of them properly. Do not save seeds from infected plants for planting in future seasons.
Pest Management for Delphinium viridescens Leib.
Delphinium viridescens Leib. is also susceptible to insect pests that can cause damage to the plant. Here are some common insect pests that might affect the plant along with ways to manage them:
Aphids
Aphids are small insects that feed on plant sap. They can cause stunted growth, yellowing of the leaves and distorted growth. To manage aphids, hose them off the plant with a strong spray of water or apply an insecticidal soap according to the manufacturer's instructions.
Caterpillars
Caterpillars are the larvae of moths and butterflies. They can feed on leaves, stems, and flowers, causing damage to the plant. To manage caterpillars: Check the plant regularly for signs of caterpillar activity, If the infestation is severe, apply an insecticide specifically labelled for caterpillars and according to the manufacturer's instructions.
Spider mites
Spider mites are tiny insects that can cause damage to the leaves of the plant. They feed by puncturing the leaf surface and sucking out the plant sap. This can cause yellowing, mottling, and distortion of the leaves. To manage spider mites, hose them off the plant with a strong spray of water or apply an insecticidal soap according to the manufacturer's instructions.
