Origin
Physocarpus alternans (M.E. Jones) J.T. Howell ssp. alternans, commonly known as desert ninebark, is a deciduous shrub that is native to the southwestern United States, including Arizona, Nevada, and California.
Common Names
Desert ninebark is also known by other names, such as purple ninebark, Hopi ninebark, and ashyleaf ninebark.
Uses
The desert ninebark has both ornamental and medicinal uses. It is a popular landscaping shrub because of its attractive foliage and flowers. The shrub produces white or pinkish-white flowers in the spring, followed by clusters of red or brown fruit in the summer.
In traditional medicine, tea made from the bark of Physocarpus alternans is used to treat sore throats, eye infections, and various respiratory problems. The plant also has anti-inflammatory properties.
General Appearance
Desert ninebark is a deciduous shrub that typically grows to a height of 3-12 feet and has a spread of 6-10 feet. The shrub has multiple stems that grow upright and are covered with dark brown bark. The leaves of the plant are round and medium green in color, with a texture that is quite hairy. They grow in clusters on the ends of the stems. In the fall season, the foliage of the shrub changes colors to shades of yellow and red.
The desert ninebark is hardy and can survive in a variety of soil types, as long as they are well-drained. The plant prefers sunny locations, but it can also tolerate some shade. It is drought-resistant, making it ideal for dry climates.
Light requirements
Physocarpus alternans (M.E. Jones) J.T. Howell ssp. alternans typically grows in areas that receive partial shade to full sun. While it can tolerate partial shade, the plant does best in full sun where it can receive around six hours of direct sunlight per day. In areas with extremely hot summers, some shading during the hottest part of the day may be necessary to protect the plant from heat stress.
Temperature requirements
The plant is native to the western United States, where it can be found growing in regions with a range of temperatures. It is hardy in USDA hardiness zones 5 to 9 and can tolerate a wide range of temperatures. However, it does best in environments where the temperature range is between 60 and 80 degrees Fahrenheit, making it well-suited to the climate in many regions of North America.
Soil requirements
Physocarpus alternans (M.E. Jones) J.T. Howell ssp. alternans is not too particular about the type of soil it grows in. The plant can tolerate a wide range of soil types including sand, loam, and clay. However, it requires well-draining soil to perform best. When it comes to soil pH, the plant prefers slightly acidic - neutral soil with a pH range between 6.0 to 7.5. Fertile soil is also ideal for promoting healthy growth.
Cultivation Methods
Physocarpus alternans (M.E. Jones) J.T. Howell ssp. alternans is a shrub that thrives in well-drained soil with a pH level ranging from slightly acidic to alkaline. Before planting, loosen the soil and mix organic matter to improve drainage and nutrient retention. The plant requires full sun to partial shade and grows well in zones 7-10. You can propagate physocarpus alternans through seeds or cuttings.
Watering Needs
The plant is moderately drought-tolerant and requires a consistent supply of water to thrive. Young plants may need regular watering until they establish their root systems. Water the plant deeply at least once a week or more frequently during dry spells. Avoid flooding the roots or leaving the soil soggy as this may cause root rot.
Fertilization
Fertilize the plant once a year during early spring using a balanced fertilizer with moderate to high nitrogen levels. Avoid over-fertilization as this may promote leafy growth at the expense of flowering. Alternatively, you can apply organic matter such as well-rotted manure or compost to improve soil nutrient levels.
Pruning
Prune physocarpus alternans during its dormant season to promote healthy growth and remove dead or diseased branches. You can also shape the plant to your desired form. Use clean sterilized pruning tools to prevent the spread of diseases. Avoid heavy pruning or shearing as this may reduce the plant's overall health and flowering ability.
Propagation of Physocarpus alternans (M.E. Jones) J.T. Howell ssp. alternans
There are several methods of propagating Physocarpus alternans (M.E. Jones) J.T. Howell ssp. alternans, including division, softwood cuttings, and seeds.
Division
Propagation by division is best done in spring when the new growth has appeared. This method involves digging up an established plant and dividing the root ball into several pieces. each division should have roots and a suitable amount of top growth.
Softwood Cuttings
The ideal time to take softwood cuttings is in early summer when the new growth is still soft and flexible. Cuttings should be 4-6 inches long and should have a few sets of leaves. Dip the cuttings in rooting hormone and plant in a suitable pot or tray with a well-draining soil mix. Keep the soil moist and keep the cuttings in a bright, sheltered location out of direct sunlight.
Seeds
Propagation of Physocarpus alternans (M.E. Jones) J.T. Howell ssp. alternans can also be done by seeds. The seeds should be collected from the plant in the fall after the seed pods have dried out. Sow the seeds in a well-draining soil mix and cover lightly with soil. Keep the soil moist and the seeds should germinate within 2-3 weeks.
Disease and Pest Management for Physocarpus alternans
Physocarpus alternans is generally a robust and healthy plant. However, there are potential diseases and pests that can attack it.
Common Diseases
One common disease affecting Physocarpus alternans is powdery mildew. Symptoms include a white, powdery substance on leaves and stems. To manage this disease, it is necessary to remove and destroy infected plant parts and to use fungicidal sprays. Another disease is leaf spot, which appears as small brown or black spots on the leaves and can lead to premature leaf drop. Pruning out infected leaves and maintaining good air circulation can help prevent the spread of this disease. Fungal disease Phytophthora root rot occurs in wet soils and leads to wilting and yellowing of leaves. The best management strategy is to improve drainage and provide good air circulation.
Common Pests
One common pest of Physocarpus alternans is spider mites, which cause a mottled appearance on the foliage. They can be managed by using insecticidal soaps or oils. Aphids can also attack the plant, which can be controlled using insecticidal soaps and oils or by introducing natural predators such as lady beetles and lacewings. Scale insects can also infest the plant, leading to yellowing of leaves and twig dieback. Pruning out infected branches and using horticultural oils can help control the spread of this pest.
In conclusion, good cultural practices such as proper watering and fertilization, pruning and maintenance of healthy soil are essential in preventing the occurrence of pests and diseases on Physocarpus alternans. Early detection and intervention are important to avoid the spread of pest and disease populations and help restore the plant to good health.
