Origin
Ericameria parryi (Gray) Nesom & Baird var. attenuata (M.E. Jones) Nesom & Baird, commonly known as Parry's rabbitbrush, is a species of flowering plant in the aster family, Asteraceae. It is native to the western United States, particularly in California, Nevada, Arizona, and Utah.
Common Names
Aside from Parry's rabbitbrush, Ericameria parryi var. attenuata is also known as slender rabbitbrush, narrowleaf rabbitbrush, and desert broom.
Uses
Historically, Native Americans used Parry's rabbitbrush for medicinal purposes, including treating headaches, skin irritations, and sore throats. The plant is also a common ornamental shrub in landscaping due to its attractive yellow blooms.
General Appearance
Ericameria parryi var. attenuata is a small, evergreen, and drought-tolerant shrub that grows up to 2 meters tall. The plant's leaves are narrow and elongated, measuring around 1-4 cm long and 1-2 mm wide. It also has numerous small flower heads in a large cluster at the stem's top, with each head measuring around 5-9 mm wide and consisting of several yellow disk florets surrounded by several yellow ray florets. The plant blooms from August to October.
Growth Conditions of Ericameria parryi var. attenuata
Ericameria parryi var. attenuata is a subshrub that is commonly found in the southwestern United States. It grows in a wide variety of habitats but prefers locations with sandy or gravelly soils. It is able to grow in both full sun and partial shade.
Light
Ericameria parryi var. attenuata is able to tolerate a wide range of light conditions, but prefers full sun to partial shade. In order to achieve optimal growth, it is recommended that this plant is grown in an area that receives full sun for at least six hours per day. If grown in partial shade, it may exhibit slower growth and produce fewer blooms.
Temperature
Ericameria parryi var. attenuata can tolerate a wide range of temperatures, but grows best in warm, dry environments. It is able to tolerate hot temperatures up to 110°F, but prolonged exposure to high temperatures can cause stress to the plant. In areas with cold winters, it generally goes dormant and may die back to the ground, but will regrow in the spring.
Soil Requirements
Ericameria parryi var. attenuata prefers well-draining, sandy or gravelly soils with low fertility. It is able to tolerate a wide range of soil pH, but does best in soils with a pH range of 6.0 to 8.0. To improve soil drainage, it is recommended to mix sand or gravel into heavy clay soils. Fertilizer should be applied sparingly as excess nutrients can cause the plant to become overly leggy and produce fewer blooms.
Cultivation Methods:
Ericameria parryi (Gray) Nesom & Baird var. attenuata (M.E. Jones) Nesom & Baird is a hardy plant that can grow well in various soil types. For optimal growth, the plant requires well-draining soils rich in organic matter. A sandy loam with a pH range of 6.0 to 7.5 is ideal for the plant. Plant seedlings 12 to 15 inches apart in a sunny location. The plant prefers full sun but can tolerate partial shade.
Watering Needs:
The plant prefers moderate watering, especially during its growth period. Watering should be done thoroughly to ensure the roots receive enough water without over-saturation. Water the plant about once every week, adjusting the frequency during hot, dry periods. Reduce watering after the plant has established, but maintain a consistent moisture level in the soil.
Fertilization:
Ericameria parryi (Gray) Nesom & Baird var. attenuata (M.E. Jones) Nesom & Baird does not require much fertilizer to grow well. An application of a balanced slow-release fertilizer during the growing season is sufficient for the plant's nutritional needs. Avoid using high-nitrogen fertilizers as they can encourage excessive foliage growth at the expense of blooming.
Pruning:
The plant requires occasional pruning to remove dead and diseased branches. Prune in late winter or early spring before new growth begins. Cut back one-third of the plant's height to promote new growth, remove any dead or broken branches, and shape the plant. Rejuvenation pruning can be done every three years to maintain the plant's vigor.
Propagation of Ericameria parryi (Gray) Nesom & Baird var. attenuata (M.E. Jones) Nesom & Baird
Ericameria parryi (Gray) Nesom & Baird var. attenuata (M.E. Jones) Nesom & Baird can be propagated both by seeds and vegetatively.
Propagation by seeds
The seeds of Ericameria parryi (Gray) Nesom & Baird var. attenuata (M.E. Jones) Nesom & Baird can be collected from mature plants. The mature seeds are black and have a pappus that aids in dissemination through the wind. The seeds should be collected just before the pods open and place in paper bags, or allow the pods to fully dry out and harvest the seeds.
The seeds should be stored in a cool and dry location until they are needed. Sow the seeds in early spring in well-draining soil that has been amended with compost. Lightly cover the seeds with soil and keep the soil consistently moist. Germination usually occurs within 2 to 4 weeks, and the seedlings can be transplanted to larger containers or into the ground when they achieve a height of approximately three inches.
Vegetative propagation
Ericameria parryi (Gray) Nesom & Baird var. attenuata (M.E. Jones) Nesom & Baird can also be propagated vegetatively using cuttings. The cuttings can be taken from mature plants in the summer and can be up to six inches in length. Small lateral branches that are semi-hardwood and have a few leaves are ideal candidates for cutting. For the best results, use a rooting hormone on the base of the cutting and plant it in a container filled with well-draining soil that has been amended with compost. The container should be placed in a location with partial sunlight, and the soil should be kept moist. After roots have formed, gently transplant the cuttings into larger containers or into the ground.
Disease Management
Ericameria parryi var. attenuata is relatively resistant to diseases that affect other plants in its family. However, it can still be affected by fungal infections such as powdery mildew and rusts. Powdery mildew is a fungal disease that appears as a white, powdery substance on the leaves, stems, and flowers of the plant. Rusts, on the other hand, appear as yellow or orange powdery masses on the underside of the leaves.
To manage powdery mildew, remove the affected parts of the plant and spray with fungicides containing potassium bicarbonate, sulfur, or neem oil. For rusts, remove the infected leaves and spray with a fungicide containing copper. To prevent the diseases, avoid overhead watering and maintain proper air circulation around the plant.
Pest Management
Ericameria parryi var. attenuata is relatively resistant to pests such as aphids and spider mites. However, it can still be affected by some pests such as cutworms, root weevils, and flea beetles. Cutworms are caterpillars that cut through the stem causing the plant to wilt and topple over. Root weevils, on the other hand, are insects that feed on the plant's roots, causing stunted growth and yellowing of the leaves. Flea beetles are small, jumping beetles that feed on the plant's leaves leaving small holes.
To manage cutworms, handpick the caterpillars and destroy them. For root weevils, apply beneficial nematodes to the soil to control the larvae. To control flea beetles, cover the plant with floating row covers or apply insecticidal soap or neem oil to repel the pests. Regular monitoring of the plant can help detect and control pests before they cause significant damage.
