Buffalo grass (Bouteloua dactyloides) is a native North American prairie species prized for its exceptional drought tolerance and low-maintenance requirements. This warm-season grass forms a dense sod using above-ground runners, called stolons, making it a resilient choice for xeriscaping and low-water lawns. While durable, buffalo grass is slow-growing and sensitive to certain chemicals, leaving it vulnerable to biological invaders and improper care practices.
Aggressive Weeds That Outcompete Buffalo Grass
Plant competition is a common cause of buffalo grass decline because the grass is a slow grower. Aggressive annual and perennial weeds quickly exploit bare or thinning areas, establishing themselves before the buffalo grass can recover. These invaders smother the desirable grass by blocking sunlight and monopolizing available water and soil nutrients.
Broadleaf weeds such as dandelion, white clover, and chickweed are problematic due to their rapid growth and ability to form dense mats. Grassy annuals like crabgrass and foxtail also pose a significant threat by rapidly filling in during the summer. These fast-spreading competitors can overwhelm a buffalo grass lawn within a single growing season if left unchecked.
Traditional broadleaf herbicides must be used with caution because the turf is sensitive to many common chemicals, such as 2,4-D. Applying these products, especially during high heat, can cause significant damage or stunting to the grass. Due to this sensitivity, physical removal or the use of specialized selective herbicides is the preferred method for controlling aggressive weed encroachment.
Insect Pests That Cause Fatal Damage
Insect infestations can lead to widespread turf death by directly attacking the root system or the grass crown. White grubs, the larval stage of various beetles, cause fatal damage by feeding voraciously on the grass roots just beneath the soil surface. This root pruning prevents the grass from absorbing water and nutrients, leading to irregularly shaped brown patches.
A tell-tale sign of a severe grub infestation is the ability to easily lift or peel back sections of the dead turf. Chinch bugs are another destructive pest, utilizing piercing-sucking mouthparts to draw sap from the grass blades and crowns. While feeding, chinch bugs inject a toxic substance into the plant tissue, causing the grass to turn yellow, then reddish-brown, and die from desiccation.
Chinch bug damage often appears first in the hottest, sunniest areas of the lawn, mimicking drought stress. While other pests, such as armyworms, feed on the grass blades above the crown, grubs and chinch bugs pose the greatest threat. Their feeding directly destroys the plant’s ability to survive.
Fungal Diseases Leading to Grass Decline
Fungal pathogens thrive in specific environmental conditions often resulting from improper watering practices. Diseases such as Brown Patch, Dollar Spot, and Grey Leaf Spot are common culprits in buffalo grass die-off. These fungi weaken the grass, making it susceptible to further environmental stress.
Brown patch is favored by high humidity and excessive moisture, often appearing as circular patches of dead turf. Dollar Spot is frequently observed when the grass is under stress from a lack of nitrogen and prolonged leaf wetness. These diseases interfere with the plant’s physiological functions, leading to leaf lesions, thinning, and eventual collapse of the turf stand.
Overwatering, particularly when done late in the day, commonly facilitates these outbreaks. Allowing water to sit on the grass blades overnight, especially during warm, humid weather, provides perfect conditions for fungal spores to germinate and spread. Correcting this cultural practice is the most effective method for preventing these infectious agents from causing widespread decline.
Management Errors That Guarantee Die-Off
Human error in maintenance practices is the most significant non-biological factor that kills buffalo grass. Overwatering is the largest management mistake, undermining the grass’s natural drought resistance and promoting root rot. Constantly saturated soil suffocates the root system, preventing necessary oxygen exchange and creating an anaerobic environment.
Buffalo grass is a sun-loving prairie species, and planting it in deep shade guarantees its decline. The grass requires full, direct sunlight for healthy growth. In areas with more than a half-day of complete shade, the turf will rapidly thin and eventually die out.
Improper chemical application is another fatal error, often causing more damage than the pests or weeds themselves. Misapplying selective herbicides or using excessive amounts of nitrogen fertilizer can chemically burn the sensitive grass blades and roots.
Improper mowing is also highly stressful to the plant. Cutting the grass too short or waiting too long between cuts depletes its energy reserves and makes it vulnerable to threats.