Sand Spikerush (Eleocharis montevidensis)

A dense, mat-forming plant, sand spikerush is a widespread coastal plant native to the southern United States and South America. The grass-like leaves are purplish at the base and grow up to 50 cm tall. Sand spikerush likes water and wet soil, so it’s often used as an ornamental or aquatic plant in pond gardens.

I. Appearance and Characteristics 

Eleocharis montevidensis is a species of spikesedge known by the common name sand spikerush. It is a widespread coastal plant native to the Americas. It grows in moist, sandy spots in many habitat types, including lakes, riverbanks, wet meadows, and springs. It has a disjunct distribution, in North America (southern United States from California to the Carolinas, Mexico, Guatemala, Honduras) and South America (Brazil, Peru, Argentina, Uruguay).

Eleocharis acicularis (Needle Spikerush) is an aquatic or marginal, annual or perennial boasting very thin, grass-like stems arising from a creeping rhizome. In shallow water it will form short spikes of tiny flowers amongst flat overlapping leafs. The tiny flowers are borne at the tip of each stem in single, sharply pointed, tiny spikelets. Submersed plants tend to be strictly vegetative, lacking spikes, and the stems can grow significantly longer than terrestrial plants, depending on the water depth.

Growing from rapidly spreading rhizomatous roots, it can form dense mats considered good habitat for fish to lay their eggs. Usually, it is grown as an oxygenating plant from the bottom of ponds or water features. The submerged leaves give off bubbles of oxygen, improving the water quality and maintaining the eco-balance of the pond. It can also absorb mineral salts from the water and reduce algae growth. Needle Spikerush is also ideal for natural ponds to help prevent soil erosion.

II. How to Grow and Care

Sand spikerush thrives in wet or aquatic environments, indicative of straightforward care routines oriented towards moisture management. The plant requires consistent soil moisture or outright submersion, positioning it as a preferred species for water gardens and pond margins. Special care points include the need for full sunlight to partial shade and monitoring to prevent excessive spread in favorable conditions.

Sunlight

Sand spikerush thrives in environments offering full sun conditions where the plant can receive uninterrupted, direct sunlight for the majority of the day. While full sun is ideal, sand spikerush exhibits an adaptable nature, tolerating partial sun with a slightly reduced growth rate and potential alterations in its foliage density and robustness. In locations with high light intensity, sand spikerush demonstrates its resilience, although prolonged exposure to lower light levels than it prefers might result in leggier growth and fewer blooms. Outdoors, sand spikerush should be planted in open areas that receive consistent sunlight to ensure optimal health and vigorous growth.

Watering

Native to marshy environments, sand spikerush thrives in consistently moist soil and exhibits a high tolerance for wet conditions. It naturally prefers the stable humidity of its swampy habitats, maintaining a delicate balance between hydration and saturation. The ideal watering schedule for this species is once every week to mimic its natural preference for regular moisture. Sand spikerush is predominantly an outdoor plant, flourishing in zones where it can bask in the full sun while its roots remain submerged or damp—emphasizing its affinity for aquatic landscapes.

Soil

Sand spikerush performs best in acidic to slightly alkaline, wet soils.

Fertilizing

For optimal growth, sand spikerush benefits from mulch or compost, offering nutrients and enhancing soil integrity. Fertilize biannually, in spring and summer, with a balanced mix to invigorate growth and ensure health. Apply a thin layer around the base without contacting stems to prevent rot. Adjust quantity seasonally, with lighter amounts in cooler months. Carefully monitor for over-fertilization signs, such as yellowing leaves or stunted growth. Consistency in application will reward gardeners with vigorous sand spikerush, showing improved resilience and vitality.

Pruning

Cut any wandering stems in the spring to control plant growth.

Propagation

Sand spikerush thrives when propagated through sowing, a method where the natural resilience and rapid growth characteristic of the species ensure successful cultivation. Start by selecting a well-draining soil composition, preferably one that mimics sand spikerush’s native wetland habitats. Sow the seeds evenly across the surface, and lightly cover them with soil to protect them from being displaced. Consistent moisture is key, so maintain a damp environment without overwatering, which could lead to rot. It is beneficial to provide indirect light and to keep the area at a moderate temperature to facilitate germination and support early growth. Once seedlings establish, they can be carefully transplanted to their final growing positions where, with minimal interference, they will develop into hardy specimens.

Transplanting

The optimal period to relocate sand spikerush is from the threshold of verdant vitality in late spring to the heart of summer, ensuring warm soil for robust root establishment. Situate sand spikerush in moist, well-drained spots to encourage successful acclimation.

Pests and Diseases

Requires little care, is virtually disease-free and pest-free. Keep an eye out for species of leaf beetles and leafhoppers in the wild.

III. Uses and Benefits 

This plant can be grown near ponds and streams, in bog gardens, or as a ground cover. It is suitable for small, medium and large ponds and can be grown as a fully submerged aquatic plant in outdoor ponds or in aquariums.