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How Fast Do Rhododendrons Grow? Facts & FAQ

yellow rhododendron flowers

While it depends on the species, most rhododendrons grow quite slowly. In fact, some can take up to 10 years to reach their full size! However, there are also some varieties that grow quite quickly, reaching their full size in just a few years.

If you’re looking for a fast-growing rhododendron, there are several varieties to choose from. However, if you want a slower-growing plant, there are still plenty of options. No matter which type of rhododendron you choose, they are sure to add beauty and interest to your landscape.

garden flower divider

What Is Rhododendron?

Rhododendron is a flowering plant that belongs to the Ericaceae family. There are over 1,000 species of rhododendrons, and they are native to Asia, Europe, and North America. Rhododendrons are evergreen shrubs that can grow to be 10 to 15 feet tall.

They have large, leathery leaves and big clusters of flowers that come in a variety of colors, including pink, purple, red, and white. Rhododendrons typically bloom in the springtime.

With proper care, rhododendrons can live for many years. In fact, some varieties can live for over 50 years!

pink rhododendrons
Image Credit: Piqsels

Do Rhododendrons Grow Quickly?

Rhododendrons can grow pretty quickly once they are established. They generally grow about 1 foot per year, but some varieties can grow up to 2 feet per year. This slow growth rate is one reason why rhododendrons are often used as foundation plants or as hedges.

How Do You Speed up Rhododendrons?

Do you wish your rhododendrons would grow faster? Here are 10 tips to speed up their growth:

1. Give Them Plenty of Room

potted Rhododendron flowers
Image By: Chamille White, Shutterstock

When planting, make sure to give each rhododendron enough space. They should be spaced at least 3 feet apart, and if you’re planting multiple in a row, 4 to 6 feet apart is even better. This way, they’ll have plenty of room to grow without being cramped.

2. Plant Them in the Spring

The best time to plant rhododendrons is in the spring after the last frost has passed. This will give them the entire growing season to get established before winter sets in again.

3. Get the Soil Right

nova zembla rhododendrons
Image By: Piqsels

Rhododendrons prefer acidic soil with a pH of 4.5 to 6. If your soil has too much alkaline in it, you can always lower its pH by adding iron sulfate or sulfur. You can also amend the soil with organic matter like peat moss or compost to make it more acidic.

4. Give Them a Good Mulch

Mulching helps your rhododendrons retain moisture and keeps their roots warm in the winter and cool in the summer. A layer of mulch 2 to 3 inches deep is ideal. Just be sure to keep the mulch away from the base of the plant so that it doesn’t rot the stem.

5. Water Them Regularly

blue peter rhododendrons
Image By: Piqsels

Rhododendrons need to be watered regularly, especially when they’re first getting established. Water them deeply and thoroughly, but don’t let the soil get soggy. A good rule of thumb is to water them about once a week or when the top inch of soil is dry.

6. Fertilize Them Twice a Year

Rhododendrons need to be fertilized twice a year, in the spring and fall. Look for a fertilizer that’s specifically designed for acid-loving plants, such as one with an N-P-K ratio of 4-8-4.

7. Prune Them in Late Winter

rhododendrons flowers
Image By: Jill Wellington, Pixabay

Pruning helps encourage new growth and keeps your rhododendrons looking their best. The best time to prune them is in late winter before new growth begins.

8. Protect Them from the Elements

Rhododendrons are fairly tough plants, but they can be damaged by harsh winds and cold temperatures. If you live in an area that gets very windy or cold, consider planting them near a building or other windbreak. And if you know a cold snap is coming, cover them with burlap or another type of light fabric to protect them from the frost.

9. Keep an Eye Out for Diseases and Pests

Image By: pixel2013, Pixabay

Rhododendrons are fairly resistant to diseases and pests, but they’re not immune. Watch out for common problems like aphids, scale, root rot, and powdery mildew. If you see any signs of these, take action immediately to treat the problem.

10. Be Patient

Rhododendrons can take a few years to really get going, so don’t be discouraged if they seem slow to grow at first. With proper care, they’ll eventually reach their full potential and provide you with beautiful blooms for many years to come.

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Final Thoughts

Following these tips will help you grow healthy, fast-growing rhododendrons. Just be patient and give them the care they need, and they’ll reward you with beautiful blooms for many years to come.

Featured Image Credit: Piqsels


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