Origin
Ambrosia chamissonis (Less.) Greene var. bipinnatisecta (Less.) J.T. Howell, commonly known as Coastal sagewort, is a flowering plant that is native to the western coast of North America, specifically from British Columbia to California.
Common names
Coastal sagewort goes by several other names, including silver burweed, silver ragweed, and beach bur.
Uses
Traditionally, Coastal sagewort was used by indigenous peoples for medicinal purposes, such as treating respiratory ailments and fever. The plant has also been used as a natural insect repellent. In modern times, it is primarily used as a decorative plant in gardens and landscapes.
General appearance
Coastal sagewort is a perennial plant that can grow up to 3 feet tall. The stems are slender and covered in fine, silver hairs, as are the leaves, which are divided into thin lobes that give the plant a feathery appearance. The flowers are small and greenish-yellow, and grow in clusters at the top of the stem. The plant produces a distinctive, pungent odor.
Light Requirements:
Ambrosia chamissonis var. bipinnatisecta requires full sun to partial shade to grow properly. In order to ensure healthy growth, the plant needs around 6-8 hours of direct sunlight per day. Insufficient light can lead to stunted growth and poor flowering.
Temperature Requirements:
Ambrosia chamissonis var. bipinnatisecta is a hardy plant and can tolerate a wide range of temperatures. The ideal temperature range for proper growth is between 10 to 30°C. However, the plant can also withstand temperatures as low as -7°C and as high as 40°C.
Soil Requirements:
The plant prefers well-drained soil with adequate organic matter. The soil pH should be between 6.0 and 7.5. It can grow in a wide range of soils, including sandy and loamy soils. However, it does not thrive in waterlogged or heavy clay soils, as they can restrict root growth and cause root rot.
Cultivation methods
Ambrosia chamissonis (Less.) Greene var. bipinnatisecta (Less.) J.T. Howell typically grows in coastal areas with sandy or rocky soil, full sun exposure, and mild temperatures. To cultivate this plant, it's essential to replicate its natural habitat conditions.
Start by selecting a location that receives at least six hours of direct sunlight and has well-draining soil. Supplement the area with organic matter to improve soil structure and nutrients. If planting from a container, ensure that the hole is twice the size of the pot. This method allows the plant's roots to grow more easily and absorb nutrients effectively.
Watering needs
The watering requirements for Ambrosia chamissonis (Less.) Greene var. bipinnatisecta (Less.) J.T. Howell are moderate. You must ensure that you don't over-water the plant since it might lead to root rot. To avoid this, allow the top one to two inches of soil to dry before watering again. During the summer months, you may need to increase the frequency of watering due to higher temperatures and dry conditions.
Fertilization
Ambrosia chamissonis (Less.) Greene var. bipinnatisecta (Less.) J.T. Howell requires occasional fertilization to supply the necessary nutrients for healthy growth. It's essential to fertilize the plant during its active growing season, typically from early spring through late summer. Use a balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium. You can also supplement the plant with organic compost to provide additional nutrients.
Pruning
Ambrosia chamissonis (Less.) Greene var. bipinnatisecta (Less.) J.T. Howell requires minimal pruning, mainly to control its shape and promote healthy growth. Pruning the plant can help in maintaining its size, removing dead or diseased parts, and reducing overcrowding. Use clean, sharp pruning shears to avoid damaging the plant. Ensure you sterilize the cutting tools before use, and cut at a 45-degree angle to promote faster healing. You can prune the plant during the dormant season, around late fall or early winter.
Propagation of Ambrosia chamissonis var. bipinnatisecta
Ambrosia chamissonis var. bipinnatisecta, also known as the coastal ragweed, is a California native plant commonly found in coastal and inland sage scrub habitats. The plant produces soft, green, finely dissected leaves with long stems and grows up to 2 meters in height. Propagation of this plant can be achieved through several methods.
Seed Propagation
The easiest propagation method is through seed as it ensures genetic diversity. The seeds ripen from July to October and can be collected by cutting the seed heads when they are at maturity. The seeds can be sowed as soon as possible in the prepared potting soil, kept moist, and maintained under a light shade. Germination can take up to 21 days and must be monitored for weeds. Transplanting outdoors should occur when the plants are approximately 10 centimeters tall.
Cuttings Propagation
Another propagation method is through cuttings. Semi-hard wood cuttings are collected during the late spring and summer months. The cuttings should possess pencil-thick stems. Cutting should be taken in the early morning or late evening when the branches are hydrated. The cuttings should be treated with rooting hormone and planted in a well-draining medium with perlite, peat or sand. Prevention of moisture loss should be ensured by covering the cuttings with plastic and maintained in a warm location. Transplanting outdoors should occur once the cuttings have developed a strong root system.
Division Propagation
The plant can also be propagated through division in the fall or winter when the plant is dormant. The plant is dug out of the soil, and the roots are washed clean. The roots should then be divided into manageable portions that include part of the stem with the crown. The divided plantlets are potted in a well-draining medium and hydrated. The plantlets should be kept in a shaded area and transplanted outdoors when the new growth begins to appear.
Disease Management:
Ambrosia chamissonis var. bipinnatisecta is a hardy plant that is susceptible to few diseases. However, it can be affected by fungal infections such as stem and root rot which can lead to the death of the plant. The best way to manage fungal infections is to provide well-drained soil and adequate watering. In addition, it is essential to remove any infected plant material and avoid over-watering.
Pest Management:
Several pests can also affect Ambrosia chamissonis var. bipinnatisecta, including spider mites, aphids, and whiteflies. A common sign of pest infestation is yellowing and curling of the leaves. The best way to manage pest infestation is through regular inspection and early detection. In addition to inspection, pest control measures such as pruning affected leaves, insecticidal soap application, and neem oil application can be helpful. Biological pest control methods such as introducing natural predators such as ladybugs can also be effective.
