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Description
Rhododendron Cosmopolitan is a beautiful flowering shrub that belongs to the family Ericaceae. It is a hybrid of Rhododendron catawbiense and Rhododendron dichroanthum, and it was first introduced in 1973 by the University of Minnesota. This shrub is known for its large, showy, pinkish-purple flowers that bloom in the late spring and early summer. The leaves are dark green and leathery, and they provide a beautiful backdrop to the colorful flowers.
Taxonomic Information
| Domain | Eukarya |
| Kingdom | Plantae |
| Phylum | Spermatophyta |
| Class | Magnoliopsida |
| Order | Ericales |
| Family | Ericaceae |
| Genus | Rhododendron |
Appearance
The Rhododendron Cosmopolitan can grow up to 6 feet tall and 5 feet wide. Its flowers are large, measuring up to 3 inches in diameter. The petals are pinkish-purple, and they have a beautiful ruffled appearance. The leaves are dark green and leathery, and they are oval-shaped with a pointed tip. When the leaves emerge in the spring, they have a bronze tint. As they mature, they turn a deep green color.
Care Guide
When it comes to caring for the Rhododendron Cosmopolitan, there are a few things to keep in mind:
- Water: This shrub needs regular watering, especially during the hot summer months. Make sure the soil is moist but not waterlogged.
- Fertilization: Use a slow-release fertilizer formulated for acid-loving plants in the spring before new growth appears. Avoid fertilizing in the fall.
- Soil: The Rhododendron Cosmopolitan prefers well-draining, acidic soil. If your soil is not acidic enough, you can add sulfur to lower the pH.
- Sunlight: This shrub prefers partial shade to full shade. Avoid planting it in direct sunlight.
- Hardiness Zones: The Rhododendron Cosmopolitan is hardy in USDA zones 4-8.
Common Pests & Diseases
The Rhododendron Cosmopolitan is susceptible to a few pests and diseases:
- Lace Bugs: These bugs suck the sap from the leaves, causing them to turn yellow and brown. Treat with insecticidal soap or neem oil.
- Root Rot: This fungal disease is caused by overwatering or poorly draining soil. Symptoms include yellowing leaves and wilting. Improve drainage and avoid overwatering.
- Leaf Spot: This fungal disease causes brown spots on the leaves. Remove infected leaves and treat with a fungicide.
Habitat
The Rhododendron Cosmopolitan is native to North America and can be found in the eastern and central parts of the United States. It prefers to grow in wooded areas with well-draining soil and partial shade.
Question and Answer
Q: How often should I water my Rhododendron Cosmopolitan?
A: Water your Rhododendron Cosmopolitan regularly, especially during the hot summer months. Make sure the soil is moist but not waterlogged.
Q: Can I plant my Rhododendron Cosmopolitan in direct sunlight?
A: No, the Rhododendron Cosmopolitan prefers partial shade to full shade. Too much sunlight can damage the leaves and flowers.
Q: When is the best time to fertilize my Rhododendron Cosmopolitan?
A: Use a slow-release fertilizer formulated for acid-loving plants in the spring before new growth appears. Avoid fertilizing in the fall.
Q: How do I lower the pH of my soil for my Rhododendron Cosmopolitan?
A: If your soil is not acidic enough, you can add sulfur to lower the pH. Follow the instructions on the package carefully.
Related Plants
- Rhododendron Catawbiense
- Rhododendron Dichroanthum
- Rhododendron Nova Zembla
- Rhododendron Yakushimanum
References
- “Rhododendron Cosmopolitan.” Missouri Botanical Garden. Accessed September 2021. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=b547
- “Rhododendron Cosmopolitan.” University of Connecticut Plant Database. Accessed September 2021. https://hort.uconn.edu/detail.php?pid=424
- “Rhododendron Cosmopolitan.” Plant Care Today. Accessed September 2021. https://plantcaretoday.com/rhododendron-cosmopolitan.html
