The term “spurge” most often refers to a group of persistent weeds belonging to the large and diverse Euphorbia genus. Homeowners typically deal with low-growing, mat-forming annuals like Spotted Spurge (Euphorbia maculata) or Prostrate Spurge. These weeds are infamous for their ability to thrive in challenging environments like sidewalk cracks, compacted soil, and thin lawns. This resilience requires a targeted approach to control and prevent its spread.
Identifying the Spurge Plant
The most definitive characteristic of any true spurge is the milky white sap, known as latex, that exudes immediately when a stem or leaf is broken. This sap is mildly toxic and can cause skin irritation or eye contact issues, so gloves should be worn when handling the plant. The common weed varieties exhibit a prostrate, or ground-hugging, growth habit, spreading outward from a central taproot to form a dense, circular mat. This low growth allows the plant to easily escape the blades of a lawnmower.
The small, oval leaves of spurge are typically arranged oppositely along the stem, which often has a reddish or pinkish hue and fine hairs. Spotted Spurge is frequently identifiable by a dark, purplish-maroon blotch located near the center of the leaf. Prostrate Spurge, by contrast, generally has lighter green leaves and lacks this central spot.
Spurge produces tiny, inconspicuous flowers from late spring through the fall, often nestled in the leaf axils. These small flowers quickly develop into three-lobed seed capsules that are a primary mechanism for the plant’s rapid spread. The presence of the milky sap is the most reliable way to distinguish spurge from other weeds that share a similar mat-forming appearance, such as prostrate knotweed.
Biological Factors Making Spurge Resilient
Spurge is difficult to control because its biology is geared toward survival and rapid reproduction. The challenge lies in its deep, woody taproot system. For annual species like Spotted Spurge, this taproot can extend over two feet into the ground, anchoring the plant firmly and allowing it to access water and nutrients long after shallow-rooted competitors have withered.
Perennial spurges, such as Leafy Spurge, possess an extensive root system that can reach depths of 15 feet or more, with horizontal lateral roots that spread aggressively. This massive root structure acts as a nutrient reserve, allowing the plant to rapidly recover and resprout even after the top growth has been completely removed. Pulling the visible portion of the plant without extracting the entire root often stimulates the remaining root fragments to produce new, vigorous shoots.
The plant’s prolific seed production is another major factor in its persistence, as a single plant can produce thousands of seeds in a season. Spurge has a short life cycle, capable of producing new seeds as quickly as five weeks after germination, ensuring continuous re-infestation throughout the summer months. The seed capsules rupture violently when ripe, flinging the seeds away from the parent plant. The seeds themselves can remain viable in the soil for several years, creating a long-term seed bank.
Effective Methods for Spurge Eradication
Successful spurge management requires a multi-pronged strategy that addresses both the existing plants and the dormant seed bank in the soil. The most foundational approach involves cultural control, centered on creating an environment where spurge cannot compete effectively. Maintaining a thick, healthy lawn through proper fertilization, aeration, and timely watering is the best defense, as dense turf crowds out the low-growing weed and prevents sunlight from reaching the soil to trigger seed germination. Applying a two-to-three-inch layer of organic mulch in garden beds will also suppress seed emergence by blocking light.
Manual and physical removal is most effective when plants are small. When hand-pulling, it is imperative to remove the entire taproot, which is best achieved after a rain or deep watering when the soil is soft. A weeding tool designed for taproots, such as a dandelion weeder, can help extract the entire structure without breaking it off at the soil line. Always wear garden gloves to protect the skin from the irritating milky sap.
Chemical control offers the fastest and most comprehensive method for established infestations, utilizing both pre-emergent and post-emergent herbicides. Pre-emergent herbicides should be applied in the spring before the soil temperature consistently reaches 60 to 65 degrees Fahrenheit, which is the range that triggers spurge seed germination. These treatments form a chemical barrier in the soil that prevents the seeds from successfully sprouting.
For plants that have already emerged, post-emergent broadleaf herbicides containing active ingredients like 2,4-D, Dicamba, or triclopyr are effective, particularly formulations labeled as safe for use on lawns. These selective herbicides target the broadleaf spurge while leaving surrounding turfgrass unharmed. The most effective application timing is often in the fall, as the plant is actively translocating nutrients down to its deep root system for winter storage. Applying a systemic herbicide during this period allows the chemical to be pulled deep into the root.