Maintenance Landscaping Design

Wild rhododendron is a spectacular plant that can grow up to 15 feet tall. It has large, dark green leaves and large, showy flowers that can be pink, purple, or white. This plant is native to the mountains of central and southern Europe, Asia, and North America.

Alternative name

• Wild Rhododendron
  
• Tree Rhododendron
  
• Large-leaved Rhododendron
  
• Purple Rhododendron
  
• White Rhododendron

Good to Know

• Wild rhododendron is an evergreen shrub that can grow to be over 15 feet tall.
  
• The leaves of wild rhododendron are large and leathery, and the flowers can be white, pink, or purple.
  
• Wild rhododendron is native to the Himalayan region, and is also found in parts of China and Japan.
  
• Rhododendrons are poisonous to humans and animals if eaten in large quantities.
  
• The flowers of wild rhododendron are used in traditional Chinese medicine.
  
• Wild rhododendron is the national flower of Nepal.
  
• Rhododendrons are considered to be one of the most beautiful flowering plants.
  
• The name "rhododendron" comes from the Greek words meaning "rose tree".
  
• There are over 1000 species of rhododendron.
  
• Rhododendrons are often used as ornamental plants in gardens.

Related plant:
Wild Privet

How to Grow

1. For wild rhododendron, first step is to find a shady spot in your garden that has moist, well-drained soil.
   
2. Clear the area of all weeds and debris.
   
3. Dig a hole that is twice the width and depth of the root ball.
   
4. Place the root ball in the hole and backfill with soil.
   
5. Tamp down the soil gently.
   
6. Water the plant deeply.
   
7. Spread a 2-inch layer of mulch around the base of the plant.
   
8. Keep the soil moist but not soggy.
   
9. Fertilize the plant yearly with a balanced fertilizer.
   
10. Prune the plant as needed to shape and control growth.

Related plant:
Wild Privet Hedge

Considering the Soil

About soil condition, wild rhododendron usually grow in well-drained acidic soil. If the soil is too heavy, it can result in waterlogging and the death of the plant. Therefore, it is important to have good drainage in the planting area.

About light

Like the other rhododendrons, wild rhododendrons need sun to prosper. They grow best in partial sun but can withstand full sun if necessary. If you live in an area with hot summers, it's best to plant them in a spot that gets morning sun and afternoon shade.

The Temperature

The temperature condition is optimal for the wild rhododendron when the temperature is cool but not cold. The wild rhododendron can tolerate temperatures as low as -15 degrees Celsius, but it will not flower if the temperature is below 5 degrees Celsius.

Humidity Level

Ideal humidity condition for this plant to grow is between 60-70%. The plant does not tolerate extreme drought or excessive moisture. The rhododendron will do best in an environment where the humidity is consistent.

Fertilizing

About fertilizer, this family of plant is heavy feeder. Fertilize plants monthly during the growing season using a balanced fertilizer such as 10-10-10. Avoid getting fertilizer on the leaves because it can burn them. For best results, apply fertilizer to wet soil. Water the plant deeply after applying fertilizer. When it comes to Rhododendron roots, they are very shallow. Because of this, the plant can dry out quickly, especially during hot weather. Be sure to keep the soil moist, but not wet.

Light requirement

Pruning a wild rhododendron is a simple process that can be done with just a few household tools. First, cut off any dead or dying branches with a sharp pair of pruning shears. Then, remove any unwanted growth, such as suckers or water sprouts, with a pruning saw or hand pruner. Finally, shape the plant by trimming back any long or out-of-place branches.

About Propagating

Propagation of wild rhododendron is by seed, layering, or cuttings. Seed is sown in autumn in a cold frame, and the seedlings are transplanted into pots the following spring. Layering is done in late summer or early autumn. Cuttings are taken from half-ripe wood in late summer or autumn and are planted in a cold frame.

Growth Rate

Usually, the plant growth rate is considered slow to medium. Depending on the species, some rhododendrons can grow up to 24 inches a year. U.S. Department of Agriculture plant hardiness zones for rhododendrons range from 4 to 9.

Basic Problems

Common problems for this kind of plant are insect pests and diseases. Insect pests include caterpillars, aphids, and mites. Diseases include root rot, powdery mildew, and leaf spot. Proper identification of the problem is critical for treatment and control.

Basics of Growing

• If you want to grow wild rhododendron, you should plant it in early spring.
  
• Rhododendron prefers full sun to partial shade.
  
• The soil should be acidic, well-drained and moist.
  
• After planting, water the plant well.
  
• Apply a layer of mulch around the plant to help retain moisture.
  
• Rhododendron doesn't require much fertilization. You can apply a slow-release fertilizer in spring.
  
• To encourage blooming, you can prune the plant in late winter.
  
• Wild rhododendron is generally pest and disease resistant.
  
• You can propagate the plant by seed or by division.
  
• When the plant blooms, the flowers are usually pink or white.

Alternative Plants

• Rhododendron arboreum
  
• Rhododendron macrophyllum
  
• Rhododendron ponticum
  
• Rhododendron ferrugineum
  
• Rhododendron luteum
  
• Rhododendron maximum
  
• Rhododendron periclymenoides
  
• Rhododendron arizelum
  
• Rhododendron groenlandicum
  
• Rhododendron campanulatum

Source:
Louisiana Plant ID | Rhododendron canescens (wild azalea) - LSU
Rhododendron PJM
Rhododendrons - Ask a Master Gardener - ANR Blogs