How To Get Rid Of Dallisgrass In St Augustine

How to Get Rid of Dallasgrass in St. Augustine

St. Augustine grass is a popular choice for lawns in the southern United States, prized for its lush green color and ability to tolerate heat and humidity. However, its beauty can be marred by the tenacious weed, dallisgrass. This invasive weed can quickly overtake your lawn if left unchecked, leaving you with a patchy and unappealing landscape. This comprehensive guide provides effective strategies for eliminating dallisgrass from your St. Augustine lawn, helping you reclaim your beautiful, healthy turf.

Understanding the Enemy: Dallisgrass

Before you begin your eradication efforts, understanding your enemy is crucial. Dallisgrass ( Paspalum dilatatum) is a perennial weed, meaning it comes back year after year. It spreads rapidly through both seeds and rhizomes (underground stems), making complete removal challenging. Its ability to thrive in various soil conditions and its tolerance to drought contribute to its invasive nature. Identifying dallisgrass is the first step in effective control. Look for these characteristics:

• Leaf blades: Wider than St. Augustine grass blades, often with a noticeable midrib.
• Seed heads: Branched seed heads, unlike the more compact seed heads of St. Augustine.
• Growth habit: Tends to grow in clumps or patches.
• Color: A slightly lighter green compared to healthy St. Augustine.

Effective Strategies for Dallisgrass Removal

There's no single magic bullet for eliminating dallisgrass, but a multi-pronged approach yields the best results. The most effective methods combine pre-emergent and post-emergent herbicides with diligent cultural practices.

1. Pre-Emergent Herbicides: Preventing the Problem

Pre-emergent herbicides are applied before the dallisgrass seeds germinate, preventing them from sprouting. This is best done in the early spring, before soil temperatures reach 55°F (13°C). Always carefully read and follow the instructions on the herbicide label. The timing and application method are crucial for effectiveness.

2. Post-Emergent Herbicides: Targeting Existing Weeds

Post-emergent herbicides are used to target existing dallisgrass plants. Several herbicides are effective on dallisgrass without significantly harming St. Augustine, but it's vital to carefully select a herbicide specifically labeled for use on St. Augustine grass. Improper herbicide application can damage or kill your desirable grass. Apply post-emergent herbicides on a day with favorable weather conditions—avoiding periods of extreme heat, cold, or rain.

3. Cultural Practices: Improving Lawn Health

A healthy St. Augustine lawn is less susceptible to weed invasion. These practices can significantly improve your lawn's resilience:

• Proper fertilization: Feeding your lawn with a fertilizer tailored to St. Augustine grass strengthens it and helps it compete with weeds.
• Regular mowing: Maintain the correct mowing height for St. Augustine, typically 2.5 to 4 inches. Avoid scalping the lawn.
• Watering: Water deeply and infrequently to encourage deep root growth.
• Thatch management: Excessive thatch can create a favorable environment for weeds. Aerate your lawn if necessary.

4. Spot Treatment: For Small Infestations

For small patches of dallisgrass, spot treatment with a post-emergent herbicide can be effective. This allows you to target the weeds directly without applying herbicide to the entire lawn.

5. Hand Pulling: A Labor-Intensive Approach

Hand pulling is effective for very small infestations or isolated dallisgrass plants. Ensure you remove the entire plant, including the roots, to prevent regrowth.

Preventing Future Infestations

Once you've eliminated the existing dallisgrass, focus on prevention. Regularly inspect your lawn for new weed growth. Use pre-emergent herbicides as a preventative measure each spring, and maintain excellent lawn care practices.

Conclusion: A Persistent but Achievable Goal

Eliminating dallisgrass from your St. Augustine lawn requires patience and persistence. By combining pre-emergent and post-emergent herbicides with diligent cultural practices, you can significantly reduce the weed population and maintain a healthy, beautiful lawn. Remember to always follow herbicide label instructions carefully and prioritize the health of your St. Augustine grass.