“Spike grass” is a general term often used to describe various grass-like plants, which can include both true grasses and sedges. These plants typically share a common appearance characterized by slender, upright growth, often with a distinctive seed head that resembles a spike. While the common name suggests a single type of plant, it encompasses several species adapted to specific environmental conditions. These plants are frequently encountered in habitats ranging from wet, marshy areas to dry, saline soils.
Understanding Spike Grass Species
The plants commonly known as “spike grass” primarily belong to two distinct botanical groups: the Eleocharis genus, often called spikerushes, and Distichlis spicata, known as saltgrass. Spikerushes are members of the sedge family (Cyperaceae). These plants are characterized by unbranched, photosynthetic stems, also known as culms, which do not have true leaves; instead, they possess sheaths at their base. The stems can vary in height, and each spikerush stem culminates in a single, small, terminal spikelet, which serves as the flower and seed head, typically ovoid or cylindrical with overlapping scales.
Conversely, Distichlis spicata, or saltgrass, is a true grass within the Poaceae family, distinguished by its ability to thrive in salty environments. This perennial plant forms dense colonies through extensive creeping rhizomes, and sometimes stolons. Saltgrass typically features rigid, erect, leafy stems that can reach up to three feet tall. Its narrow, stiff green leaves are notable for their ability to excrete excess salt, which can sometimes result in a visible salt crust on their surface. The flowers of saltgrass are borne in a crowded, spike-like panicle, with male and female reproductive parts typically found on separate plants.
Preferred Habitats and Growth
Different “spike grass” species exhibit varied preferences for their growing environments. Many Eleocharis species, or spikerushes, are frequently found in moist, sandy locations such as lake margins, riverbanks, and wet meadows. These plants are well-suited to aquatic or mesic conditions, capable of growing submerged in water, and thrive in light conditions ranging from full sun to partial shade.
In contrast, Distichlis spicata, commonly known as saltgrass, is specifically adapted to high-saline and alkaline soils. This species is a common sight in coastal salt marshes, inland saline flats, and even high desert seeps. Saltgrass prefers wet, saline, or alkaline soil conditions, yet it also shows remarkable adaptability to drier soil types like silts, clays, and sands. It requires full sun exposure and can withstand regular or tidal inundation, forming dense mats through its network of rhizomes.
Ecological Impact and Practical Uses
“Spike grass” species play a valuable role in their natural ecosystems and offer several practical applications. Their extensive root systems and dense growth habits provide effective erosion control, particularly in wet or saline environments, aiding in shore stabilization. These plants also create important habitats and food sources for various wildlife, including waterfowl, shorebirds, and small mammals. Additionally, some species serve as larval food plants for certain butterflies.
Beyond their ecological contributions, these plants have practical uses for humans. Saltgrass is particularly beneficial for revegetating saline or alkaline areas and is frequently utilized in wetland restoration projects due to its resilience. Historically, saltgrass served as a significant source of hay for early colonists and continues to be grazed by livestock, including cattle and horses, especially during dry periods when other forage might be scarce. Some Eleocharis species are even cultivated for human consumption.
Management and Control
Managing “spike grass” effectively depends on whether its presence is desired or unwanted within a given landscape. For areas where these plants are considered a nuisance, mechanical methods can be employed, such as cutting or removing spikerush, though persistent efforts may be needed due to their spreading nature. For more widespread or stubborn growth, certain chemical options, like herbicides containing active ingredients such as Diquat or Fluridone, have shown effectiveness against spikerush. Biological controls, such as the use of grass carp, can consume spikerush.
Conversely, when “spike grass” is desired for specific purposes, cultivation practices can promote its growth. For instance, planting Distichlis spicata for erosion control or restoration projects involves selecting sites with full sun and wet to moist soil conditions. Propagating saltgrass is often done by planting plugs or rhizomes, spaced approximately one foot apart, ideally in late spring. Eleocharis species can be propagated through root division or by seed.