Greater marsh St. John's wort (Triadenum walteri)

Also known as: Walter's St. John's-wort, Small St. John's-wort

The Greater marsh St. John's wort (Hypericum elodes) features yellow star-shaped flowers and oval, opposite leaves that are often covered in a fine downy hair. This plant flourishes in wet, marshy areas such as bogs, fens, and along the edges of ponds and streams. It thrives in acidic, nutrient-poor soils and exhibits a creeping growth habit, forming dense mats that contribute to soil stabilization in these moist environments.

In This Article

Care Tips Water Sunlight Temperature Soil Fertilize Prune Propagation Repotting

Attributes of Greater marsh St. John's wort

Lifespan

Perennial

Plant Type

Herb

Plant Height

0.5 to 1 meter

Spread

N/A

Leaf Color

Green, often with a gland-dotted underside

Flower Size

0.5 to 1 centimeter

Flower Color

Pink to rose

Images of Greater marsh St. John's wort

Quickly Identify Greater marsh St. John's wort

Triadenum walteri can be identified by its erect, herbaceous stems, opposite leaves, and clusters of small, pink to rose-colored flowers. The ovate leaves often have a noticeable gland-dotted underside.

Scientific Classification of Greater marsh St. John's wort

Phylum

Vascular plants

Class

Dicotyledons

Order

Malpighiales

Family

St. John's wort

Genus

Marsh St. John's wort

Species

Greater marsh St. John's wort

Planting and Growing of Greater marsh St. John's wort

Care Difficulty

Moderate

Watering Schedule

Every 4 days

Sunlight Requirements

Partial sun

Sunshine Duration

4-8 hours

Ideal Temperature

70-85℉

Soil Type

Potting Mix, Peat Mix

Soil pH

5.5-6.8

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 Greater marsh St. John's wort?

Triadenum walteri thrives with moderate watering, ensuring the soil remains consistently moist but not waterlogged. Water about 250 ml until it's well absorbed into the soil, allowing the excess to drain.

What are the symptoms of an underwatered Greater marsh St. John's wort? ›

What should I do if my Greater marsh St. John's wort is not getting enough water? ›

What are the symptoms of an overwatered Greater marsh St. John's wort? ›

How to save an overwatered Greater marsh St. John's wort? ›

What Are the Sunlight Requirements for Greater marsh St. John's wort?

Sunlight Requirements: Partial sun, Partial shade

Duration of light: 3-6 hours

Triadenum walteri thrives in partial sun or light shade environments, where it benefits from moderate light levels. Ideal lighting encourages balanced growth, vibrant flowering, and resilience against stressors.

What type of light is best? ›

How to achieve ideal lighting? ›

What are the benefits of perfect lighting? ›

What Is the Ideal Temperature Range for Greater marsh St. John's wort?

Ideal Temperature: 70 ~ 85℉

Triadenum walteri thrives best when the temperature is maintained between 70°F and 85°F. This temperature range promotes optimal growth, flowering, and overall plant health. Ensuring this range helps the plant efficiently carry out photosynthesis and other metabolic processes essential for its vitality.

What Soil is Best for Greater marsh St. John's wort?

Soil type: Sandy soil, Loam, Acidic soil

Soil PH: 5.5 ~ 6.8

Triadenum walteri thrives in soils with good moisture retention, which helps maintain consistent hydration levels for the plant, especially during dry periods. This capability ensures the plant's lush growth and prolonged blooming phase. The plant benefits from a nutrient-rich substrate that can supply essential minerals and nutrients. Adding compost or organic matter can significantly enhance the nutrient profile, fostering healthy root development and vibrant foliage. While moisture is crucial, good drainage is equally important to prevent waterlogging. Sandy or loamy soil with organic amendments can ensure that excess water flows away, which reduces the risk of root rot and supports vigorous plant health.

How to Fertilize Greater marsh St. John's wort?

Fertilizer type: Balanced

Triadenum walteri prefers moderate feeding, so it is essential to use a balanced fertilizer. A liquid feed diluted to half-strength is ideal. Apply no more than 10-15 ml per plant, ensuring you do not overfeed.

How to Prune Greater marsh St. John's wort?

Pruning Time: Spring, Summer, Autumn

Begin by inspecting Triadenum walteri for any damaged, diseased, or dead stems. Using sharp, clean pruning shears, make clean cuts to remove these sections and to shape the plant. Focus on removing excessive growth to allow light penetration and air circulation. Prune back any leggy stems to encourage a bushier growth. Ideally, cut just above a leaf node or branch point to promote healthy regrowth. For best results, always sterilize your tools before and after pruning to prevent disease spread. More About Pruning Techniques→

How to Propagate Greater marsh St. John's wort plant?

Propagate Time: Spring, Early summer, Late summer, Early autumn

Fill seed trays with a good quality seed-starting mix, ensuring it's moist but not waterlogged. Scatter the seeds evenly over the surface, and cover them lightly with the mix. Place the trays in a warm, bright location, maintaining consistent moisture until germination occurs.

Select healthy stems from the parent plant and cut lengths of about 4-6 inches. Remove lower leaves and dip the cut end into rooting hormone. Plant the cuttings in a well-draining potting mix, and keep the soil moist while avoiding waterlogging.

Carefully dig up the plant, avoiding damage to the root system. Use a sharp knife to separate the root ball into smaller sections, each with healthy roots and shoots. Re-plant the divisions in prepared soil, water well, and provide appropriate care as they establish.

More About Propagating Techniques→

How to Repot Greater marsh St. John's wort plant?

Repotting frequency: Every 2-3 years

Triadenum walteri signals its need for repotting when its roots start to circle the inside of the container or when growth appears stunted despite routine care. Repot in early spring or summer when the plant's growth cycle is accelerated, allowing it to adjust swiftly to a refreshed environment.

Selecting a new pot for Triadenum walteri should involve looking for a container that is one size larger than its current home, with ample drainage holes. This ensures proper drainage and room for root expansion, helping prevent waterlogging while supporting healthy growth.

Opt for a soil mix that is loamy and well-draining, as Triadenum walteri prefers moist but aerated conditions. This type of soil enhances root health by preventing excess water accumulation and encourages steady growth through optimal nutrient supply.