Great laurel (Rhododendron maximum)

Also known as: Rosebay rhododendron, Summer rhododendron

The great laurel, or Rhododendron maximum, is an evergreen shrub native to North America, particularly thriving in the Appalachian Mountains. Known for its clusters of soft white or pink blooms and shiny oval leaves, this resilient plant prefers the cool, moist environments of mountain slopes and stream banks.

In This Article

Care Tips Water Sunlight Temperature Soil Fertilize Prune Propagation Repotting Toxicity

Attributes of Great laurel

Lifespan

Perennial

Plant Type

Shrub

Plant Height

1.5 m to 10 m

Spread

1.5 m to 3.5 m

Leaf Color

Green

Flower Size

2.5 cm to 3 cm

Flower Color

White Pink Purple

Images of Great laurel

Quickly Identify Great laurel

Large, leathery leaves in a whorled arrangement with smooth, glossy surfaces.

Bell-shaped flowers with pink to white hues and fringed lobes, bearing hair-like structures.

Oblong seed capsule with a mechanism for dehiscence, revealing tiny seeds in autumn.

Dark green leaves with rust-colored hairs underneath, 4 to 8 inches (10 to 20 cm) long.

Trunk bark transitions from smooth, light brown surface to scaled texture, staying slender.

Scientific Classification of Great laurel

Phylum

Vascular plants

Class

Dicotyledons

Order

Ericales

Family

Heath

Genus

Azaleas

Species

Great laurel

Planting and Growing of Great laurel

Care Difficulty

Easy

Watering Schedule

Every 2 days

Sunlight Requirements

Partial sun

Sunshine Duration

4-6 hours

Ideal Temperature

50-70℉

Soil Type

Potting Mix, Peat Mix

Soil pH

4.5-6

Fertilizer Type

Balanced

Pruning Season

Spring, Summer

Pruning Area

Branches, Leaves

Pruning Frequency

2 times a year

Repotting Season

Spring

Pot Type

Plastic, Ceramic

How to Water Great laurel?

For Rhododendron maximum, the watering amount should be sufficient to keep the soil consistently moist but not waterlogged. A deep soaking of approximately 500 milliliters per watering is ideal. This ensures the roots absorb enough water without sitting in excess liquid, which can lead to root rot.

What are the symptoms of an underwatered Great laurel? ›

What should I do if my Great laurel is not getting enough water? ›

What are the symptoms of an overwatered Great laurel? ›

How to save an overwatered Great laurel? ›

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What Are the Sunlight Requirements for Great laurel?

Sunlight Requirements: Partial sun, Full shade

Duration of light: 2 to 6 hours

Partial shade to partial sun is the ideal environment for this plant, allowing sustainable energy acquisition for robust flowering while minimizing risk of heat stress.

Where should I place Rhododendron maximum? ›

How to ensure the plant gets optimal light? ›

What benefits does ideal light provide? ›

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What Is the Ideal Temperature Range for Great laurel?

Ideal Temperature: 50 ~ 70℉

Rhododendron maximum thrives best in a mild climate with consistent temperatures between 50°F and 70°F. This range supports its physiological processes, promoting healthy growth and flower development. Maintaining this temperature range ensures good metabolic function and minimizes plant stress, which leads to vibrant and lush foliage.

What Soil is Best for Great laurel?

Soil type: Loam, Acidic soil, Sandy loam, Peat soil

Soil PH: 4.5 ~ 6

Rhododendron maximum thrives in well-drained soil as it prevents root rot by ensuring excess water does not accumulate around the roots, promoting robust growth. A rich mix of organic material in the soil is essential for Rhododendron maximum. It provides vital nutrients needed for the plant’s lush foliage and stunning blooms. The soil should retain moisture without becoming waterlogged, so the plant roots remain hydrated, which is crucial during dry spells for sustained health. More About Soil→

How to Fertilize Great laurel?

Fertilizer type: Balanced

For Rhododendron maximum, it's important to apply a balanced amount of fertilizer to support healthy growth. Typically, use a slow-release granular fertilizer with a formulation like 10-10-10. Apply 1 pound per 100 square feet, ensuring not to exceed this quantity as it can lead to root damage and nutrient burn. More About Fertilizing Techniques→

How to Prune Great laurel?

Pruning Time: Spring, Summer, Autumn

Begin by examining the plant for any branches or stems that appear dead, diseased, or damaged. Use sharp pruning shears to make clean cuts at the base of these stems. Removing unhealthy wood not only shapes the plant but also promotes a healthier rhododendron by preventing the spread of disease. To maintain an aesthetically pleasing shape, selectively prune branches that disrupt the natural growth pattern. Cut back overgrown branches to a growth node, ensuring sunlight can penetrate the inner parts of the plant. Thinning the shrub allows for better air circulation, reducing the risk of pest infestations. After flowering, lightly trim the tips of the branches to encourage the development of next season's flower buds. Avoid harsh cuts as they can stunt growth; instead, aim to trim just enough to promote future blooms while retaining the plant's elegant form. More About Pruning Techniques→

How to Propagate Great laurel plant?

Propagate Time: Early spring, Late spring, Early summer

Select a healthy branch from the parent plant and cut a 4 to 6-inch section. Ensure the cutting includes at least two nodes and remove the leaves from the bottom half.

Dip the cut end of the cutting into a rooting hormone to encourage faster root development. This can significantly increase the success rate of the cuttings rooting.

Insert the cuttings into a moistened rooting medium, such as a mixture of peat and perlite. Place them in a warm, bright location but out of direct sunlight.

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How to Repot Great laurel plant?

Repotting frequency: Every 2-3 years

Rhododendron maximum should be repotted when you notice it becoming root-bound, showing slow growth, or when the soil drains poorly. Spring and Autumn are ideal as the plant is either coming out of or going into its dormant phase, allowing it to handle the stress of repotting better.

Select a pot that is 2 inches larger in diameter than the current one, with proper drainage holes. A slightly larger pot encourages root development without causing excessive soil moisture, which helps prevent root rot and provides ample space for future growth.

Opt for a soil mix rich in organic matter with a pH between 4.5 and 6. It's crucial for supporting the Rhododendron's preference for acidic conditions, promoting healthy root growth and helping retain moisture without waterlogging.

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Toxicity of Great laurel

Is Great laurel toxic to humans?

The Great laurel possesses toxic characteristics that can adversely affect humans if ingested. Consuming any parts of this plant can lead to severe complications, with the most serious cases potentially resulting in life-threatening conditions. Both the leaves and flowers, along with the nectar, are poisonous. Symptoms that may arise from consuming these parts include a decreased heart rate and lower blood pressure, which can rapidly escalate to fatal consequences. Some individuals may consume the plant or honey derived from it, believing in its purported health benefits, often without recognizing the true extent of its toxicity. Given its popularity as an ornamental species in home gardens, children can easily access and ingest this plant, often completely unaware of the inherent dangers.

Is Great laurel toxic to cat?

The great laurel is a harmful plant species that poses toxicity risks to cats. Feline companions may inadvertently consume various components of great laurel since every part of this plant is toxic. Upon ingestion, a cat may display symptoms indicating significant physical distress or illness. Therefore, it is crucial for cat owners to be aware of these distress signals and to prevent their pets from accessing great laurel. Should a cat ingest any part of this plant, it is essential to obtain urgent care at a veterinary clinic to treat the poisoning and reduce the risk of further health issues.

Is Great laurel toxic to dog?

The great laurel is recognized as toxic to dogs. If canines ingest any part of this plant, they risk poisoning due to the inherent toxic properties found in all sections. Symptoms of great laurel poisoning in dogs can include gastrointestinal distress, lethargy, irregular heart rate, and potentially severe reactions, contingent on the quantity consumed. Dog owners must take precautions to keep their pets away from areas where great laurel is present and remain vigilant for any indications of accidental ingestion. If a dog exhibits symptoms that suggest great laurel poisoning, seeking immediate veterinary assistance is essential to secure the best possible outcome for the affected pet.

WARNING

The judgment on toxicity and danger is for reference only. We DO NOT GUARANTEE any accuracy of such judgment. Therefore, you SHALL NOT rely on such judgment. It is IMPORTANT TO SEEK PROFESSIONAL ADVICE in advance when necessary.

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