Largeleaf Phlox (Phlox amplifolia)

Also known as: Largeleaf Phlox

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In This Article

Care Tips Water Sunlight Temperature Soil Fertilize Prune Propagation Repotting Toxicity

Attributes of Largeleaf Phlox

Lifespan

Perennial

Plant Type

Herb

Plant Height

66 cm to 76 cm

Spread

50 cm to 60 cm

Leaf Color

Green

Flower Size

2 to 3 centimeters

Flower Color

Pink Purple

Images of Largeleaf Phlox

Quickly Identify Largeleaf Phlox

Phlox amplifolia can be identified by its large, ovate to elliptical green leaves and its terminal clusters of tubular, five-lobed flowers that range from white to pink or lavender.

Scientific Classification of Largeleaf Phlox

Phylum

Vascular plants

Class

Dicotyledons

Order

Ericales

Family

Phlox

Genus

Phloxes

Species

Largeleaf Phlox

Planting and Growing of Largeleaf Phlox

Care Difficulty

Easy

Watering Schedule

Every 4 days

Sunlight Requirements

Partial sun

Sunshine Duration

6-10 hours

Ideal Temperature

60-75℉

Soil Type

Potting Mix, Peat Mix

Soil pH

5.5-7.5

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 Largeleaf Phlox?

For Phlox amplifolia, aim to water deeply, ensuring the soil is moist but never waterlogged. Each watering session should provide around 500 milliliters. The goal is to soak the root zone without leaving the plant in standing water.

What are the symptoms of an underwatered Largeleaf Phlox? ›

What should I do if my Largeleaf Phlox is not getting enough water? ›

What are the symptoms of an overwatered Largeleaf Phlox? ›

How to save an overwatered Largeleaf Phlox? ›

What Are the Sunlight Requirements for Largeleaf Phlox?

Sunlight Requirements: Partial sun, Full sun

Duration of light: 4-6 hours

Phlox amplifolia requires partial to full sun, which means four to six hours of daily sunlight. This ensures optimal photosynthesis, resulting in lively growth, prolific flowering, and disease resistance.

How much light does Phlox amplifolia need? ›

What are some solutions to provide ideal lighting? ›

How does ideal lighting affect Phlox amplifolia? ›

More About Sunlight Requirements Techniques→

What Is the Ideal Temperature Range for Largeleaf Phlox?

Ideal Temperature: 60 ~ 75℉

Phlox amplifolia thrives best within a temperature range of 60°F to 75°F, where it can maintain optimum health and grow robustly. This range offers sufficient warmth for photosynthesis and overall physiological processes without the stress of excessive heat.

What Soil is Best for Largeleaf Phlox?

Soil type: Loam, Sandy loam

Soil PH: 5.5 ~ 7.5

Phlox amplifolia thrives in soil that retains moisture well but also drains efficiently. Loam and sandy loam are ideal as they balance moisture retention and drainage, supporting consistent hydration without waterlogging. This plant benefits from nutrient-rich soil, requiring adequate organic matter to flourish. Regularly adding compost can ensure a steady supply of nutrients, boosting growth and flowering. Avoid overly compacted soils; ensure good drainage to prevent root rot. Incorporating sand into the soil mix can facilitate better drainage, promoting root health and oxygenation.

How to Fertilize Largeleaf Phlox?

Fertilizer type: Balanced

For Phlox amplifolia, it's crucial to apply fertilizers in moderation to avoid root burn. A good rule of thumb is to use a quarter to a half strength of the recommended amount on the fertilizer package. This plant prefers a balanced fertilizer like a 10-10-10 or 5-10-5 NPK ratio, diluted in water for liquid applications.

How to Prune Largeleaf Phlox?

Pruning Time: Spring, Summer

Begin pruning by removing dead or damaged stems. This clears the way for new growth and helps prevent disease from spreading. Cut back to just above a healthy leaf node. To maintain an attractive shape, trim back overgrown stems and spent flowers. This encourages the plant to grow fuller and bloom more profusely. Aim to create a balanced structure with evenly distributed foliage. More About Pruning Techniques→

How to Propagate Largeleaf Phlox plant?

Propagate Time: Spring, Early summer

Harvest mature seeds from healthy Phlox amplifolia plants in the late summer or early autumn. Ensure the seeds are fully dry before storing them in a cool, dry place until the next planting season.

Cut 4-6 inch sections from healthy stems using sterilized pruning shears. Ensure each cutting has at least two nodes. Remove any leaves from the bottom half to reduce moisture loss.

In spring, carefully dig up established Phlox amplifolia plants. Use a garden fork to separate the roots, ensuring each division has a viable root system. Replant immediately to promote establishment.

More About Propagating Techniques→

How to Repot Largeleaf Phlox plant?

Repotting frequency: Every 2-3 years

Phlox amplifolia shows signs of needing repotting when you notice roots emerging from the drainage holes or when the plant's growth seems stunted. Ideally, repot in spring to give the plant a chance to settle into its new home during the growing season.

Select a pot that is 1-2 inches larger in diameter than the current pot. Choose a container with drainage holes to prevent waterlogging, promoting healthy root growth and preventing root rot, which is crucial for maintaining a healthy Phlox amplifolia.

Opt for a well-draining loamy soil mix, which ensures optimal water retention and airflow to the roots. This soil type helps reduce the risk of root diseases, offering a robust environment for Phlox amplifolia to thrive.

Toxicity

N/A

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.