Juncus - Rush: Planting and Care

Botany and description

Juncus, commonly known as rushes, are herbaceous plants belonging to the Juncaceae family. The genus Juncus, comprising around 300 species, derives its name from the Latin word juncus, meaning “binding” or “tie”, as the stems of certain species were traditionally used to make ropes or weave baskets. In natural habitats, rushes are most recognisable by their rigid stems, often round and smooth, and their small, discreet flowers in clusters. Among the most well-known rushes is Juncus effusus, or Soft Rush, characterised by its tall, upright stems, frequently used in landscaping near water features.

Juncus thrive in wet and marshy environments, such as riverbanks, pond edges or flood meadows. Due to their strong affinity for waterlogged soils, they play an important ecological role, contributing to bank stabilisation and water filtration. They can be found worldwide, though they are particularly common in temperate regions of the northern hemisphere, as well as in some tropical and subtropical areas, usually at higher altitudes. Their ability to withstand challenging growth conditions makes them particularly well-suited to wetland ecosystems, while also granting them remarkable resilience to climatic variations.

From left to right: Juncus effusus, Juncus conglomeratus and Juncus acutus

Juncus, or rushes, are plants with an upright and slender habit, often forming tight clumps of straight stems that rise directly from the base. Their form is thin and cylindrical, giving them a rigid, vertical silhouette, ideal for aquatic landscapes. The root system is fasciculate, consisting of a dense network of fibrous roots that allow them to anchor firmly in wet and marshy soils. These roots help stabilise banks while enabling the plant to efficiently draw water and nutrients needed for growth.

The foliage of Juncus is distinctive: the leaves are often reduced to sheaths surrounding the stems, and may even be absent, leaving the stem itself to perform photosynthesis. When present, the leaves are slender, cylindrical or flattened, and inconspicuous, blending in with the stems.

The inflorescence of Juncus is discreet yet elegant, composed of small flowers in clusters or panicles that appear along the stems or at their tips. The flowers, though small, have a complex structure with tiny brown or greenish tepals, which are rather modest in appearance. Fruiting occurs in the form of capsules containing numerous small seeds. These capsules split open when ripe, allowing the seeds to disperse via water or wind, thus promoting the spread of the species in surrounding wetland habitats.

Did You Know? The term to strew comes from the word rush. In the past, it was common to spread rushes, foliage or flowers on the ground to create a natural carpet, both decorative and practical. Rushes were used to scent, soften and insulate the floors of medieval dwellings.

Juncus patens, and on the right, top: Juncus subuliflorus and bottom: Juncus acutus

Our favourite varieties

Juncus effusus

The diffuse rush forms a clump composed of cylindrical stems arranged in a fan shape, dark green and evergreen in winter. Its reddish-brown spikelets bloom at the top of the stems in summer. Its purifying properties are valuable for maintaining the biological balance of the pond. Its rootstocks stabilise the banks while serving as a refugium plant and ecological shelter for pond wildlife.

• Flowering time August, September
• Height at maturity 50 cm

See the product sheet

Juncus effusus 'Spiralis'

Juncus effusus 'Spiralis' develops corkscrew-like stems that are either upright or trailing and evergreen. Guaranteed graphic effect!

• Flowering time August to October
• Height at maturity 50 cm

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Juncus ensifolius

Juncus ensifolius or sword-leaf rush is a small rush with blackish-brown flowers on flattened, sword-shaped stems of light green colour.

• Flowering time August to October
• Height at maturity 40 cm

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Juncus inflexus Blue Dart

Juncus inflexus Blue Dart, sometimes sold as Juncus tenuis Blue Dart, is an interesting rush variety for its bluish-toned foliage. It produces loose spikelets of reddish-brown colour in midsummer.

• Flowering time August to October
• Height at maturity 45 cm

See the product sheet

How to plant rushes?

Where to plant?

Rushes thrive in moist soils, making them perfect for areas near water, such as pond edges, marshy zones or waterlogged garden soils. A clay or loamy soil, which retains water well, is ideal for them, as it stays moist longer and promotes root development. However, they are not suited to dry or sandy soils, which drain too quickly and may cause them to dry out. If your soil is drier or sandier, you can enrich it with compost and add a layer of organic mulch to help retain moisture. They also prefer slightly acidic to neutral soil.

Choose a location where they will have access to direct or partial light, as although they tolerate shade, they will grow better with some sunlight.

On riverbanks, rushes help stabilise the soil

When to plant?

Ideally, plant rushes in spring or autumn, when the soil is still cool and moist, which encourages root establishment.

How to plant?

• • Loosen the soil well in the chosen spot by turning it over and breaking up clumps to promote good root development.
  • Check that the soil is sufficiently moist before planting. If necessary, water the area to ensure consistent moisture levels favourable to rushes.
    • In open ground:
      • Dig a hole the same depth and width as the plant’s container to give it space without compressing its roots.
      • Carefully remove the rush from its container.
      • Place the rush in the prepared hole, adjust it to ensure it’s straight, then fill the hole with soil, lightly firming it. Avoid compacting the soil too much to maintain good aeration for the roots.
      • Water thoroughly after planting to settle the rush and maintain soil moisture levels.
    • In a pond:
      • Choose a large pot or planting basket, ideally perforated, to allow good water exchange.
      • Fill the pot with clay soil or a mix suitable for aquatic plants, and plant the rush in it.
      • Weigh the pot down slightly with pebbles or stones to prevent it from floating in the water.
      • Position the pot so that it is partially submerged in the pond, ensuring the top of the root ball remains above water to prevent the rush from being submerged.

Juncus Care

Watering

Rushes require constantly moist soil to thrive, especially when planted in the ground. If the plant is in the ground but away from a water source, make sure to water it regularly to keep the soil moist, particularly during hot or dry periods. For rushes grown in a pond or partially submerged container, check the water level frequently to ensure they never lack moisture.

Pruning

Rushes require little pruning, but it can be helpful to remove dry, yellowed or damaged stems in early spring to encourage vigorous growth and maintain a tidy appearance. Use a pair of clean scissors or secateurs to cut these stems at the base. This light pruning also helps to aerate the clump and prevent debris buildup.

Some varieties of rushes can be invasive in damp areas, such as Juncus effusus or Juncus inflexus. To control their spread, remove any new shoots that stray from the main clump. If you grow them in a submerged container, this naturally limits their growth and prevents them from colonising the surrounding space.

Diseases and Pests

Rushes are generally very resistant plants to diseases and pests, but certain environmental conditions can still make them vulnerable.

Rushes can be susceptible to rust, a fungal disease that causes orange to brown spots on stems and leaves. Although uncommon, rust can spread quickly in conditions of high humidity and heat. Remove affected parts and ensure good air circulation around the plants to reduce moisture.

Snails and slugs may occasionally nibble on the tender stems of young rushes, particularly in spring.

Propagating rush plants

In nature, rushes propagate by sowing and through the development of the rootstock. In the garden, we multiply our rushes by dividing clumps. Division of clumps is preferably done in spring or autumn, when the plant is in active growth, but temperatures are not too extreme. This allows the rush to recover more easily after division.

• Preparing the plant: water the base of the plant well to facilitate extraction. Then, carefully dig up the rush clump with a spade or fork, taking care not to damage the roots.
• Division: with your hands or a sharp tool, divide the clump into several sections, each containing a good portion of roots and a few stems. Ensure each division has enough roots to establish quickly after transplanting.
• Replant immediately the divisions in moist soil, in the desired location (in the ground or in a pot). Dig holes of the same depth as the divisions, then place the clumps and cover with soil without compacting too much. If planting in a pond, place each division in a suitable planting basket, weighted if necessary to prevent floating.
• Watering and monitoring: water well after planting to help the roots establish, and maintain consistent moisture to encourage recovery. During the first few weeks, check that the soil remains moist and that the new clumps show signs of growth.

Association

To create a lush wetland area, we’ll design a vibrant, natural scene by playing with heights, colours and shapes of plants suited to waterlogged soils.

Let’s start by structuring the base of this wetland with Juncus effusus ‘Spiralis’. Its upright, corkscrew-like stems bring a graphic, minimalist touch, perfect for creating a backdrop. Plant them in clumps in the wettest areas, where they’ll help stabilise banks and filter the water. Their bright green colour contrasts elegantly with more vividly coloured flowers.

For added height and floral intensity, introduce Lobelia cardinalis, or Cardinal Flower. Its vivid red blooms instantly catch the eye. Plant them near the rushes, where moisture is constant but roots can still breathe.

Next, let’s add an aquatic, poetic atmosphere with different iris species. The classic Iris pseudacorus, with its striking yellow flowers, and Iris versicolor ‘Variegata’, with its blue and purple hues (and variegated foliage!), bring wild yet refined charm. These irises thrive in waterlogged soils and pair beautifully with rushes and lobelias.

Asclepias incarnata, or Swamp Milkweed, enriches this palette with its soft pink umbels. Plant them in small clumps to add gentle touches among more rigid foliage.

Finally, to dress the edges and provide denser ground texture, add wetland sedges like Carex riparia. Their herbaceous clumps and glossy evergreen foliage create a smooth transition between flowering plants and the soil. Their rapid spreading makes them excellent ground covers that unify the whole scene.

Iris versicolor, Juncus effusus ‘Spiralis’, Carex riparia, Lobelia, Asclepias incarnata and Iris pseudacorus