Introduction
Delphinium californicum Torr. & Gray ssp. californicum also known as California larkspur is a perennial herbaceous plant belonging to the Ranunculaceae family. It is a native plant to California, USA, and mainly grows in the Sierra Nevada mountain.General Appearance
The Delphinium californicum Torr. & Gray ssp. californicum is a tall plant that can grow up to a height of 3-6 feet. It has hairy leaves that are deeply cut, and the flower stalks have blue-violet petals with white centers. Its fruits are capsules with numerous seeds covered in a brownish-grey coating. The plant's roots are deeply penetrating and can go up to two meters deep.Common Names
The Delphinium californicum Torr. & Gray ssp. californicum has several common names, which include California larkspur, dark purple larkspur, California delphinium, and Sierra larkspur.Uses
The Delphinium californicum Torr. & Gray ssp. californicum has various uses, such as its medicinal properties. The plant's seeds and leaves are used to make a potent, fast-acting poison that was used by Native Americans to hunt game. The poison was also used as a weapon during wars. However, it is essential to note that this plant contains toxic alkaloids that can be poisonous to both humans and livestock, thus should be handled with care. The plant also has ornamental value, and its beautiful flowers are used for decorative purposes in gardens and floral bouquets. Additionally, it has ecological value as it provides food and shelter to various wildlife species like bees, birds, and butterflies. In conclusion, the Delphinium californicum Torr. & Gray ssp. californicum is a beautiful plant with impressive ecological and medicinal attributes. However, its toxic properties should not be overlooked, and it should be handled with care.Light Requirement
Delphinium californicum Torr. & Gray ssp. californicum grows best in full sun but can also tolerate partial shade. In areas with hot summers, it prefers some afternoon shade.
Temperature Requirement
It is adaptive to a wide range of temperatures and can tolerate both hot and cold temperatures. The ideal temperature range for its growth is between 15°C and 25°C (60°F - 77°F).
Soil Requirement
Delphinium californicum Torr. & Gray ssp. californicum prefers deep, well-drained soils, but it can also grow in shallow soils. An ideal soil for its growth is loamy sand, with a pH range between 6.0 and 8.0. It can, however, grow on alkaline soils with pH levels as high as 8.5. The plant requires sufficient soil moisture but cannot tolerate waterlogging as it is susceptible to root rot.
Cultivation Methods
Delphinium californicum Torr. & Gray ssp. californicum can be grown from seeds or transplanted from grown plants. The ideal planting time is in the fall, but it can also be done in the spring. They prefer full sun to partial shade and well-draining soils. The plants are relatively tolerant to drought and heat, but excessive moisture can cause root rot. The recommended spacing between plants is about 18 inches.
Watering Needs
Delphinium californicum Torr. & Gray ssp. californicum requires regular watering throughout the growing season. The plant prefers evenly moist soil, so it is recommended to water deeply once or twice a week when there is no precipitation. However, it's essential not to let the soil become waterlogged, which can cause root rot or other diseases.
Fertilization
The plants generally do not require much fertilizer. Incorporating organic matter into the soil before planting can provide them with necessary nutrients, but it should be done with moderation. Too much nitrogen can cause excessive foliage growth and result in fewer flowers. If necessary, use a balanced fertilizer once or twice during the growing season.
Pruning
Pruning is not necessary, but it can help to shape the plant and stimulate new growth. After the blooming period is over, Deadheading can prolong flowering and prevent seed formation, which can take the energy away from the plant. Cutting the entire plant down to a few inches from the soil level in the fall can help it survive the winter and rejuvenate for the next season.
Propagation of Delphinium californicum Torr. & Gray ssp. californicum
Delphinium californicum Torr. & Gray ssp. californicum, commonly known as California larkspur, can be propagated through several methods.
Seed Propagation:
The most common method of propagating Delphinium californicum is through seeds. To start with, collect ripe seed pods in autumn, usually September or early October. Soil preparation is critical to get good results with seed propagation. First, loosen the soil and remove all weeds, debris, and rocks. Add some organic matter like compost or well-decomposed manure. Sow the seeds shallowly in the prepared soil. Keep the soil moist but not waterlogged. Germination usually takes around two to three weeks. When the seedlings are strong enough, transplant them to larger containers or outdoors in a prepared bed.
Division:
Dividing the root clumps of mature Delphinium californicum plants is another propagation method. This technique should be done when the plant is still dormant in late autumn or early spring. Gently dig up the entire plant, and remove the soil around the roots. Cut the root clump into sections, with each one having a healthy shoot and some roots. Replant the divided sections in a location with full to part sun and good drainage, ensuring the soil is well watered to settle them in.
Cuttings:
Although not commonly used, Delphinium californicum can also be propagated through stem cuttings. Take several stems of mature plants, cut them just below a node, and remove the lower leaves. Dip the cut ends in rooting hormone and plant them in prepared soil. Keep the soil moist and warm until you see new growth. After some weeks, the cuttings should have developed roots and can be transplanted to a larger container or garden bed.
Disease Management
Delphinium californicum Torr. & Gray ssp. californicum is vulnerable to various diseases, including powdery mildew, botrytis, and root rot. Powdery mildew is a fungal disease that appears as a white or gray powdery coating on the leaves. Botrytis is another fungal disease that causes the plant to rot and die. Root rot is caused by waterlogging and can cause the roots to decay, leading to plant death.
To manage powdery mildew, ensure there is proper air circulation around the plant, avoid overhead watering, and apply fungicides. For botrytis, remove infected plant parts and improve air circulation. Use fungicides if necessary. To prevent root rot, use well-draining soil and avoid watering excessively. Remove any infected plant parts and use fungicides if required.
Pest Management
Delphinium californicum Torr. & Gray ssp. californicum can be attacked by various pests, including slugs, snails, and aphids. Slugs and snails feed on the leaves, flowers, and stems of the plant, leaving large holes and often causing significant damage. Aphids feed on the plant's sap and cause stunted growth and distorted leaves.
To manage slug and snail infestations, handpick the pests, remove them from the garden, and use baits such as beer traps. You can also create a barrier around the plant using copper tape or diatomaceous earth. To control aphids, spray the plant with insecticidal soap or neem oil. You can also use ladybugs or lacewings, which are natural predators of aphids, to control infestations.
