Origin
Magnolia macrophylla Michx. ssp. ashei (Weatherby) Spongberg, commonly known as Ashe's magnolia, is a deciduous tree species belonging to the Magnoliaceae family. It is native to the southeastern United States, specifically found in parts of northeast Georgia, western North Carolina, and eastern Tennessee. The plant thrives in moist, well-draining soils in full sun or partial shade, making it popular among gardeners and landscapers.
Common Names
Ashe's magnolia is commonly known by several names, including Bigleaf Magnolia, Ashe's Bigleaf Magnolia, Ashe's Magnolia, Greatleaf Magnolia, and Large-leaved Magnolia. The plant was named after William Willard Ashe, a prominent American forester and botanist of the early 20th century, who discovered and documented the species in 1901.
Uses
Ashe's magnolia has several uses, both commercially and domestically. Its wood is hard and durable, making it suitable for making furniture, flooring, and cabinet work. The plant's bark has also been used in traditional medicine to make treatments for various ailments, including coughs, colds, and fever. Ashe's magnolia is also widely used as a decorative plant in gardens, parks, and public spaces, thanks to its lovely flowers and large, glossy leaves.
General Appearance
Ashe's magnolia is a large deciduous tree, growing up to 80 feet tall and 40 feet wide. It has large, glossy green leaves that can reach up to 3 feet in length, making them one of the largest leaves of any North American native tree species. The plant's flowers are also impressive, with large white or creamy-white blooms that can measure up to 10-12 inches in diameter. The flowers bloom in late spring to early summer, attracting pollinators like bees and butterflies, and giving the tree a picturesque appearance. Ashe's magnolia fruit is a unique oblong-shaped cone that can measure up to 8 inches long and 3 inches wide, with an orange-red hue when mature.
Light Requirements
Magnolia macrophylla Michx. ssp. ashei (Weatherby) Spongberg thrives in full sun to partial shade conditions. It can tolerate direct sunlight exposure, especially during mornings, but it generally prefers to have some shade during warmer hours. Too much shade, however, can negatively affect its growth and blooming.
Temperature Requirements
This plant subspecies is known for its admiration for warm climates. It flourishes in USDA Hardiness Zones 6 to 9, which corresponds to winter temperatures between -23 to 25°F (-31.6 to -3.9°C). Its optimal growth temperature range is between 60F-90F (15.6C-32C), with average temperature in the summer months ranging between 75-85°F (24-29°C). It could face challenges if subjected to extreme low temperatures in the winter months and could lead to damage or death of the plant.
Soil Requirements
This subspecies of Magnolia macrophylla requires soil that is well-draining and rich in organic content. It thrives in moist soils, but it should never be waterlogged. When planted, it is recommended to incorporate compost or other organic matter in the soil to aid in water retention. This plant can tolerate mildly acidic to neutral pH parameters of 5.0 to 7.5 in soil. It is not recommended to plant this subspecies in regions where the soil has a high salinity content, as it can damage the plant's growth significantly.
Cultivation
Magnolia macrophylla Michx. ssp. ashei thrives well in well-drained soils with slightly acidic to neutral pH levels. It grows well in full sun or partial shade and is tolerant of low temperatures that can reach up to -20°C. The plant is propagated by planting seeds in a suitable environment that can foster germination.
Watering Needs
Like most plants, Magnolia macrophylla Michx. ssp. ashei requires consistent watering to thrive. It needs significant rainfall or irrigation during the growing season. However, the soil should not be waterlogged as it can cause root rot, which can be detrimental to the plant's health.
Fertilization
Magnolia macrophylla Michx. ssp. ashei requires nutrients for optimal growth and health. Generally, fertilization should be done during the growing season, which is between spring and summer. A balanced fertilizer containing nitrogen, potassium, and phosphorus can be applied to the soil around the base of the plant. The amount of fertilizer to use depends on the plant's size and the soil's nutrient content.
Pruning
Magnolia macrophylla Michx. ssp. ashei can be pruned to manage its size and shape. The best time to prune is after the flowering period, which is usually in late spring or early summer. Dead or diseased branches should be removed to promote healthy growth. However, pruning should be minimal as the plant can be sensitive to it, and excessive pruning can weaken the plant.
Propagation of Magnolia macrophylla Michx. ssp. ashei (Weatherby) Spongberg
Magnolia macrophylla Michx. ssp. ashei (Weatherby) Spongberg, commonly known as the Ashe magnolia, can be propagated through various methods such as seed germination, layering, grafting, and cuttings. However, propagation through seed germination is the most preferred method for large scale propagation.
Seed Germination
The seeds of Magnolia macrophylla Michx. ssp. ashei are dark red and 1-2 inch long. Collect the seeds during the fall season and store them in a cool, dry place until spring. The seeds require stratification for approximately 3-4 months in the refrigerator before planting.
Prepare a seedbed by mixing peat moss, sand, and perlite in equal amounts. Sow the seeds approximately 1 inch deep in the seedbed. Water the seeds regularly and keep the seedbed moist. After germination, transplant the young seedlings into individual containers and care for them until they become mature enough for transplantation.
Layering
Layering is a simple propagation method that can be used to propagate Magnolia macrophylla Michx. ssp. ashei by rooting shoots from the stem. In late summer, select a low-lying branch that is flexible enough to bend to the ground without breaking.
Cut a slit in the bark approximately 4-6 inches away from the stem, dust the wound with rooting hormone, and bend the branch down to the ground. Secure the branch to the ground using wire or a peg, and cover the wounded area with soil, allowing the tip of the branch to be exposed.
Keep the soil moist and wait for roots to form at the wounded area. After rooting, cut the rooted branch from the parent plant and plant it into the ground or in a container.
Grafting
Grafting is a propagation method used to combine the rootstock of one plant with the scion of another plant. This method is commonly used to propagate cultivars or ornamental forms of Magnolia macrophylla Michx. ssp. ashei.
Select a healthy rootstock and a scion that is approximately the same diameter as the rootstock. Cut a slit in the rootstock and scion to match each other. Insert the scion into the rootstock, making sure the cambium of the two plants align. Bind the two plants together using tape or a grafting clip.
After grafting, cover the joint with grafting wax or a plastic bag to prevent water loss. Keep the grafted plant in high humidity and bright light. After the graft has healed, plant the plant into the ground or into a container.
Cuttings
Cuttings are a propagation method where a section of the stem is removed and planted into the ground or a container. Cuttings of Magnolia macrophylla Michx. ssp. ashei can be taken from the current season's growth during the late spring or early summer.
Select a healthy stem, approximately 6-12 inches long, and cut the stem below a node. Dip the cut end of the cutting into rooting hormone and plant it in a container filled with a well-draining potting mix. Keep the soil moist and keep the container in bright, but indirect light. After rooting, transplant the rooted cutting into the ground or a larger container.
Disease and Pest Management for Magnolia macrophylla Michx. ssp. ashei (Weatherby) Spongberg
Magnolia macrophylla Michx. ssp. ashei is a tree species native to the southeastern region of the United States. It is commonly grown for its large, fragrant, and showy flowers, making it a popular ornamental plant. However, like any other plant, it is susceptible to various diseases and pests that may affect its growth and health. The following are common diseases and pests that might affect Magnolia macrophylla Michx. ssp. ashei and the ways to manage them.
Diseases
1. Leaf Spot Disease - This disease is caused by various types of fungi, and it affects the leaves of Magnolia macrophylla Michx. ssp. ashei, causing them to develop small, dark-colored spots. The spots may merge, leading to premature defoliation and reduced photosynthesis, which ultimately affects the health and growth of the plant. To manage this disease, the affected leaves should be removed and destroyed, and the surrounding soil should be kept clean and dry. Applying fungicides can also be helpful in managing the disease.
2. Powdery Mildew - This disease is caused by the fungus Erysiphe magnoliae, and it affects the leaves and buds of Magnolia macrophylla Michx. ssp. ashei, causing a powdery white coating on them. The affected leaves may also curl and drop prematurely, leading to stunted growth and reduced vigor of the plant. To manage this disease, the infected plant parts should be removed and destroyed, and the surrounding soil should be kept clean and dry. Applying fungicides and practicing good cultural practices such as proper watering and fertilization can also be helpful.
Pests
1. Scale Insects - These insects are small and immobile, and they often go unnoticed until they cause serious damage to the plant. They infest the leaves and stems of Magnolia macrophylla Michx. ssp. ashei, sucking sap and weakening the plant. To manage this pest, the affected plant parts should be removed and destroyed, and the surrounding soil should be kept clean and dry. Applying insecticides may also be helpful in managing the infestation.
2. Japanese Beetle - This insect feeds on the leaves of Magnolia macrophylla Michx. ssp. ashei, causing skeletonization and defoliation of the plant. The infestation can seriously affect the plant's growth and vigor. To manage this pest, handpicking the beetles can be effective, or applying insecticides can also be helpful in managing the infestation.
In conclusion, managing disease and pest infestations in Magnolia macrophylla Michx. ssp. ashei is important to maintain the plant's overall health and growth. By practicing good cultural practices, such as proper watering and fertilization, and applying appropriate management methods, the plant can continue to thrive and beautify the landscape.
