Irrigation and Drought Management

Water is the lifeblood of a healthy lawn, but getting the balance right is essential. Too little water can leave your grass dry, brittle, and prone to dormancy, while too much can lead to shallow roots, disease, and wasted resources. In the South, scorching summer heat and extended dry spells make efficient watering techniques a must. Understanding how and when to water will not only keep your lawn lush and green but also conserve water and save on utility costs.

This chapter dives into the essentials of lawn irrigation, from determining the right amount of water for your grass type to timing your watering for maximum absorption and minimal waste. You’ll also learn about selecting drought-resistant grass varieties that can thrive with less water, as well as proactive steps to take when faced with water restrictions or severe drought conditions. With the right strategy, you can maintain a resilient, healthy lawn that stands up to the challenges of the Southern climate.

How Much Water Does a Lawn Need?

A general rule of thumb is that most lawns need about 1 inch of water per week (from rain or irrigation) during the growing season to stay healthy. This can vary: in cooler spring/fall, they may need less; in peak summer on sandy soil, maybe a bit more. An inch of water typically soaks the soil 6–8 inches deep, reaching the root zone.

You can measure how long it takes your sprinkler system to deliver an inch by placing straight-sided cans (like tuna cans) around the yard while running the sprinklers. If it takes 45 minutes to fill the cans to 1 inch, then you might water for 45 minutes once a week. If you prefer to water twice a week, you might do 20–25 minutes each time. Adjust based on your system’s output and any rain you receive.

Watering Frequency and Timing

It’s generally best to water deeply and infrequently rather than a little bit every day. Deep watering means soaking the soil well below the root zone, encouraging roots to grow downward in search of moisture. Infrequent watering allows the soil to dry out slightly between waterings, which reduces waste and prevents diseases.

For many southern lawns on decent soil, this means watering once or twice a week when there isn’t enough rain. For example, you might water your lawn 0.5 inches on Tuesday and 0.5 inches on Friday. If your soil is heavy clay, once a week with 1 inch might be enough since clay retains moisture longer. Sandy soil may require 0.5 inches twice a week, as it doesn’t hold much water.

Best Time to Water

The best time to irrigate is early in the morning, between 4 a.m. and 9 a.m. At this time, temperatures are cooler, winds are calmer, and the lawn will dry off after sunrise, reducing the risk of fungal disease.

Avoid watering during the middle of the day, as much of it will evaporate before reaching the roots. Also, avoid watering in the evening or at night since grass blades staying wet overnight increases the risk of disease. If you must water later in the day, aim for the late afternoon so the grass can dry before nightfall.

If you use an automatic sprinkler system, set it to run in the early morning. If you rely on manual sprinklers, try to water different zones in the morning over a couple of days.

Signs Your Lawn Needs Water

Instead of watering on a rigid schedule, learn to read your grass for signs of drought stress:

• Grass blades begin to fold or curl lengthwise.
• The lawn takes on a dull bluish-gray color instead of vibrant green.
• Footprints or mower tracks remain visible because the grass doesn’t spring back.

If you see these signs in a section of your lawn, it’s time to water. Waiting until this stage ensures you’re not overwatering while also preventing the grass from becoming too dry and going dormant.

Avoid Daily Shallow Watering

A common mistake is running sprinklers every day for 10 minutes. This only wets the top half-inch of soil, leading to shallow roots that dry out quickly. Daily watering also promotes weed growth and lawn disease.

Instead, it’s better to apply 0.5 inches every four days than 0.125 inches every day, even if the total weekly water amount is the same. The exception is for newly seeded lawns or fresh sod, which need daily watering until established.

Efficient Irrigation Techniques

Besides watering at the right time and frequency, consider these strategies to maximize efficiency:

• Zone Your Irrigation: Ensure your sprinkler system is properly adjusted so that lawn areas are watered separately from flower beds, as their water needs differ.
• Cycle Soak Method: If you have heavy clay soil or sloped areas where water runs off, break watering into two shorter cycles. Water for 15 minutes, pause for an hour to allow absorption, then resume watering.
• Rain Sensors and Moisture Meters: Automatic systems should have a rain sensor or soil moisture meter to prevent watering right after rainfall.
• Check Coverage: Sprinklers don’t always distribute water evenly. Place multiple cans around the yard to ensure all areas receive adequate water.
• Hand Watering Hot Spots: Some areas, like those near sidewalks that reflect heat, may dry out faster. Instead of overwatering the entire lawn, hand-water just those sections.

Drought Management and Grass Selection

Choose Drought-Tolerant Grasses

If you’re selecting a grass type for a hot, dry region, choose a variety with strong drought tolerance:

• Best drought tolerance: Bermudagrass, Zoysiagrass
• Moderate tolerance: St. Augustinegrass, Tall Fescue
• Poor drought tolerance: Centipedegrass
• Extreme drought tolerance: Bahiagrass, Buffalograss (for drier climates)

Bermudagrass and Zoysia are the best choices for enduring drought. If watering restrictions or frequent droughts are an issue in your area, these grasses are more likely to survive and recover quickly.

Letting the Lawn Go Dormant During Drought

During a prolonged drought, warm-season grasses enter survival mode by turning brown and dry while their roots remain alive. Dormant turf can survive for weeks or even months without rain, but excessive dryness may cause some loss.

If watering isn’t possible, it’s usually okay to let a warm-season lawn go dormant. It will brown out but can recover when rain returns. However, lawns that lack rhizomes, like St. Augustine, may suffer permanent patchy damage.

Drought Survival Watering: Even in dormancy, give your lawn a deep watering every 3–4 weeks to keep the roots alive. The grass won’t turn green, but this will prevent desiccation and death. If it hasn’t rained in a month, apply 0.5–1 inch of water.

Mowing and Fertilizing During Drought

• Raise Mowing Height: Taller grass shades the soil, reducing moisture loss.
• Avoid Mowing Wilted Grass: Mow when the lawn is hydrated, preferably in the morning.
• Reduce Fertilization: Don’t apply nitrogen fertilizer to a drought-stressed lawn, as it will encourage new growth the grass can’t support. Instead, focus on potassium applications to help improve drought resistance.

Watering Restrictions and Alternative Solutions

• Prioritize High-Need Areas: If watering is limited, focus on sun-exposed areas and high-traffic zones.
• Use Rain Barrels: Collect roof runoff for use in your lawn and landscape beds.
• Apply Soil Wetting Agents: These products help sandy soil retain moisture longer.
• Consider Landscape Adjustments: If a section of your lawn constantly struggles, replace it with drought-tolerant ground covers or mulch.

Keeping Your Lawn Green in Summer

If your goal is to maintain a green lawn throughout the summer without letting it go dormant, combine these practices:

• Water deeply and early in the morning
• Raise mowing height in July–August
• Apply potassium fertilizer in spring and summer to improve heat tolerance
• Watch for fungal diseases and treat as needed
• Provide shade relief where possible, especially in heat-reflective areas

Warm-season grasses thrive in summer as long as moisture is sufficient. With proper care, your lawn can stay green even through Southern heat waves.

By following these guidelines, you’ll significantly reduce water waste while keeping your lawn healthy and resilient in hot, dry weather. With smart irrigation and drought-conscious practices, your Southern lawn can thrive even when the rain is scarce. In the next post, we’ll cover how to revive and repair a lawn that has suffered from drought, pests, or neglect.