Overview of Rhus ×ashei (Small) Greene (pro sp.)
Rhus ×ashei (Small) Greene (pro sp.) is a hybrid plant that belongs to the family Anacardiaceae. The plant is a cross between Rhus copallinum (winged sumac) and Rhus aromatica (fragrant sumac). It is commonly referred to as Ashe's sumac, Florida sumac, or dwarf sumac.
Origin of Rhus ×ashei
Rhus ×ashei is native to the southeastern United States, particularly in Florida, but can also be found in Georgia and Alabama. The plant typically grows in dry, sandy soils, where other plants struggle to thrive. It is known for its ability to withstand drought and poor soil conditions.
Appearance of Rhus ×ashei
Rhus ×ashei is a small to medium-sized shrub that can grow up to 6-10 feet in height and width. Its leaves are deciduous, with serrated edges and a shiny green color that turns into a beautiful reddish-orange in the fall. The plant produces clusters of small, yellowish-green flowers in the spring, followed by red, fuzzy fruit in the summer that attracts birds and other wildlife.
Uses of Rhus ×ashei
The plant has several uses, both ornamental and medicinal. Its lush foliage and bright color make it an excellent landscaping plant for dry and barren soils. The fruit of the plant, when crushed, can be used to make a refreshing lemonade-like beverage that is rich in vitamin C. The foliage of this plant has also been used to make a tea that is believed to have medicinal properties, including anti-inflammatory and antiseptic effects.
However, it is important to note that while Rhus ×ashei has many useful purposes, it can also cause allergic reactions in some people. The plant produces urushiol, an oily resin that can cause skin irritation, similar to poison ivy. Therefore, it is advisable to use caution when handling this plant.
Light Requirements
Rhus ×ashei is adapted to grow in full sun to partial shade conditions. It grows well in open areas, along roadsides, on disturbed sites, and in woodlands with moderate shade. However, it cannot tolerate deep shade conditions.
Temperature Requirements
Rhus ×ashei is a heat-loving plant and grows best in warm climates with hot summers. It is adapted to grow in USDA hardiness zones 7a to 9b, which have an average annual minimum temperature ranging from 0 to 30°F (-18 to -1°C) and an average annual maximum temperature ranging from 95 to 105°F (35 to 41°C).
Soil Requirements
Rhus ×ashei is adaptable to a wide range of soil types, including sandy, loamy, and clayey soils. It prefers well-drained soils with a pH range of 6.0 to 8.0. However, it can also tolerate poorly drained soils and soils with high salinity levels.
The plant is drought-tolerant and can grow in areas with low annual rainfall. However, it grows faster and produces more fruit in areas with higher rainfall and periodic flooding.
Cultivation Methods
Rhus ×ashei is a hardy plant and can grow well in a variety of soil types, including sandy and loamy soils. It is able to tolerate both drought and flooding, making it a low-maintenance plant. Optimal planting time is in spring or fall, when soil temperatures are around 60°F. Plant in an area that receives full sun, with at least six hours of direct sunlight per day. Ensure proper drainage by planting in a raised bed or on a slope.
Watering Needs
This plant prefers well-draining soil and does not require excessive watering, particularly if the soil is already moist. Water the plant only when the soil has dried out, and avoid overwatering. Rhus ×ashei is drought-tolerant, and overwatering can cause root rot and other fungal diseases to develop. Water deeply approximately every two weeks, depending on rainfall and temperature conditions.
Fertilization
Rhus ×ashei is a low-maintenance plant and does not require excessive fertilization. The plant will benefit from an annual application of all-purpose fertilizer in the early spring, before new growth appears. Alternatively, an organic fertilizer such as compost or worm castings can be added to the soil to replenish nutrients. Avoid using high-nitrogen fertilizers, as this can promote excessive foliage growth and detract from the overall appearance of the plant.
Pruning
Pruning can be done annually in the winter to remove dead or damaged branches, or to shape the plant as desired. Rhus ×ashei can also be pruned in the late spring or early summer after it has flowered. Pruning will encourage new growth and improve the plant's overall appearance. Wear gloves and protective clothing when pruning, as the plant contains oils that can cause skin irritation. Disinfect pruning tools between cuts to prevent the spread of disease.
Propagation Methods for Rhus ×ashei
Propagation of Rhus ×ashei (Small) Greene (pro sp.) can be done through several methods as follows:
Seed Propagation
Seeds of Rhus ×ashei can be collected from mature fruits or purchased from certified nurseries. The seeds must be cleaned and sown in well-drained soil during late winter. The seeds should not be buried deep and should be covered with only a thin layer of soil. The soil must be kept moist and the seeds must be exposed to full sunlight for better germination. Seeds will germinate within 2-3 weeks, and the seedlings can be transplanted once they reach a height of 5 cm.
Softwood Cutting Propagation
Rhus ×ashei can be propagated using softwood cuttings collected from new growth. Softwood cuttings are taken during early summer and must be treated with rooting hormone before planting in well-draining soil. The cuttings should be planted deep enough to provide stability and allow the foliage to remain above the soil surface. The soil should be kept moist and the cuttings exposed to light shade until they root. Typically, softwood cuttings will root within 4-6 weeks, and can be transplanted into permanent locations.
Air Layering Propagation
Air layering is another propagation method that can be used for Rhus ×ashei. This method is preferred for trees that are difficult to propagate using other methods. Air layering involves removing a section of bark from a branch and covering the area with moist sphagnum moss or peat moss. The area is then covered with plastic wrap to maintain humidity around the exposed area. Roots will start to form in a few weeks, and when the roots are well established, the branch can be cut off from the parent tree and planted as a new plant. Air layering should be done during early spring or summer.
Common diseases of Rhus ×ashei
Rhus ×ashei, commonly known as Ashe's Smooth Sumac, is prone to various diseases and pests. Let's discuss some of the common diseases that might affect the plant.
- Leaf spots: The plant is susceptible to leaf spot diseases caused by different fungi, including Phoma exigua, Cercospora spp., and Septoria spp. The primary symptoms of the disease are circular to irregular brown lesions on leaves.
- Powdery mildew: Powdery mildew is caused by the fungus Erysiphe pulchra. The disease affects the leaves and stems, producing a white powdery coating that inhibits photosynthesis, leading to stunted plant growth and poor flowering.
- Fungal cankers: The disease is caused by various fungi, including Botryosphaeria dothidea and Diplodia spp. The primary symptoms of cankers are sunken areas on the stem with discolored bark, eventually causing dieback.
Disease management
Effective disease management strategies involve sanitation, cultural control, and chemical control:
- Sanitation: Remove the infected plant material and dispose of it far away from the garden. Clean pruning tools with a disinfectant to prevent the spread of disease.
- Cultural control: Plant resistant varieties, maintain adequate plant spacing, and provide good sunlight and air circulation to prevent humidity build-up, which might encourage fungal growth.
- Chemical control: Use fungicides labeled for powdery mildew, leaf spots, or cankers as per instructions to protect plants from disease. Remember to apply the fungicides when the plant is dry, and avoid spraying during hot and humid conditions.
Common pests of Rhus ×ashei
The common pests that might infest Rhus ×ashei include:
- Scale insects: Scale insects pierce the plant tissue and feed on sap, leading to yellowing leaves, stunted growth, and plant decline. The insects can be identified by their brown, waxy coating on stems and leaves.
- Aphids: Aphids are small, oval-shaped insects that suck plant sap, leading to curling and yellowing leaves. They also excrete honeydew, attracting ants and promoting sooty mold growth on leaves.
- Caterpillars: Caterpillars chew on leaves, leading to defoliation and reduced plant vigor. Some of the common caterpillar pests of Rhus ×ashei include the Fall webworm and the Imported Cabbageworm.
Pest management
Pest management strategies involve sanitation, cultural control, and chemical control:
- Sanitation: Remove and dispose of the infested plant material far away from the garden. Clean pruning tools with a disinfectant to prevent the spread of pests.
- Cultural control: Encourage natural enemies of pests, such as ladybugs and lacewings, by planting nectar plants like dill and fennel in the garden. Also, maintain the garden hygiene to reduce pest hiding places and breeding sites.
- Chemical control: Use insecticidal soaps, oils, or botanicals like neem oil, pyrethrin, or spinosad, depending on the pest type and severity. Remember to follow the instructions provided on the label and test a small area of plants before applying to observe the reaction.
