Orchard grass (Dactylis glomerata) is a cool-season perennial grass that often becomes a persistent weed in lawns, gardens, and agricultural fields. This aggressive species has a distinctive clumping growth habit and vigorous nature, allowing it to outcompete desired vegetation. Its rapid growth, especially after mowing, makes it a visually disruptive nuisance in turfgrass settings. Successfully removing this invader requires a targeted strategy that addresses both its established root system and its ability to spread by seed. This guide outlines methods for effective eradication and long-term control.
Identifying Orchard Grass
Distinguishing orchard grass from desirable turfgrasses is the first step before removal. Orchard grass is a bunch-type grass, forming large, dense tufts rather than spreading via stolons or rhizomes. This growth pattern results in conspicuous, coarse clumps that stand out sharply against a uniform lawn.
The blades often have a gray-green or bluish-green color, notably lighter than most common lawn varieties. A key identifying feature is the flattened stem base, which is strongly compressed and appears somewhat like a folded fan. These coarse leaves also possess a prominent white midrib and grow much faster than surrounding turf, creating an uneven texture after mowing. When allowed to mature, the plant produces a stiff, branched seed head from late spring into midsummer.
Non-Chemical Removal Techniques
Several manual and physical methods can effectively kill orchard grass, particularly when infestations are small or localized, allowing homeowners to avoid synthetic chemicals.
Manual Removal
The most direct approach is manual removal, which targets the plant’s deep, fibrous root crown. This method requires a shovel or specialized weeding tool to dig out the entire clump, ensuring the root ball is removed to a depth of at least three to four inches. Any remaining root fragments can lead to regrowth, so thorough removal is necessary. The excavated area should be immediately filled and reseeded.
Smothering and Solarization
For larger, non-turf areas, smothering and solarization utilize environmental conditions to eliminate the grass. Smothering involves covering the infested area with an opaque barrier, such as heavy cardboard or thick black plastic, topped with mulch. This technique starves the grass of light, causing it to die and decompose over several months.
Solarization is a more rapid, heat-intensive method best performed during the hottest summer months. This process involves covering a moist, affected area with a sheet of clear plastic, which traps solar radiation and dramatically increases the soil temperature. The heat generated beneath the plastic can reach temperatures lethal to the grass and its seeds. For effective results, the clear plastic should be kept tightly sealed for two to four weeks.
Herbicide Options for Eradication
When non-chemical methods are impractical due to the size of the infestation, herbicides provide the most efficient means of eradication. No selective herbicide is available to homeowners that can kill a mature perennial grass like orchard grass without harming the surrounding desirable turf. Consequently, the most reliable chemical control is a non-selective herbicide, such as glyphosate, which kills any plant it contacts.
This non-selective approach mandates a precise spot-treatment application, targeting only the orchard grass clump to minimize damage to the lawn. For the herbicide to be most effective, the grass must be actively growing, making spring and fall the optimal application windows. The product must be absorbed by the leaves and translocated down to the deep root system to achieve a complete kill.
Due to the plant’s robust perennial nature, a single application may not be sufficient, and a follow-up treatment is often required if signs of regrowth appear. After the treated clumps have turned completely brown, which usually takes about seven to ten days, the dead material should be removed. The area can then be reseeded or patched with sod approximately seven days after the initial application, once the herbicide has degraded sufficiently.
Long-Term Management and Prevention
Eliminating established orchard grass must be followed by cultural practices that prevent its return.
Seed Source Control
The most common source of new orchard grass is contaminated grass seed, often listed as “other crop seed” on the label. Prevention begins by purchasing high-quality turf seed guaranteed to contain 0.0% “other crop seed” to avoid introducing the weed.
Cultural Practices
Maintaining a dense, healthy lawn is the best defense against weed establishment, as thick turf competes aggressively for resources. After removing a clump, overseeding the bare spot with a desirable turfgrass species helps quickly fill the void, preventing new seeds from germinating. Adjusting the mower height to the upper end of the recommended range helps shade the soil surface, suppressing the light necessary for weed seed germination. Proper fertilization practices also support dense turf growth, further outcompeting any stray seedlings.