If you want a green lawn during Arizona’s scorching summers, timing is everything. Knowing exactly when to plant summer grass in AZ is the single most important step for success. Get it right, and you’ll establish a tough, heat-loving turf. Get it wrong, and you’ll waste time, money, and water on poor germination. This guide gives you the clear, simple timing and steps you need.
Summer grasses here are warm-season varieties like Bermudagrass and Zoysia. They thrive in heat but go dormant and turn brown in winter. They need warm soil to sprout and grow strong roots before the extreme heat hits full force.
When to Plant Summer Grass in AZ
This is your golden rule. The optimal window for seeding summer grass in Arizona is from late April through mid-July. Aim for soil temperatures consistently above 65°F, which usually happens when daytime air temps are reliably in the 80s.
Why This Timing is Critical
Planting during this period gives your grass the best possible start. The warm soil speeds up germination, and the lengthening days provide plenty of sunlight. Most importantly, it allows the young grass plants to develop a deep root system before the most intense summer stress arrives in late June and July. If you seed to late, the seedlings will be to weak to handle the extreme heat.
Regional Variations in Arizona
Arizona’s climate isn’t the same everywhere. Your specific location will fine-tune your planting date.
- Low Deserts (Phoenix, Tucson, Yuma): Your window opens earliest. Target late April to June. The goal is to have grass established before 110°F days become the norm.
- High Desert & Intermediate Zones (Prescott, Payson): Wait a bit longer for the soil to warm. The best time here is typically mid-May through early July.
- Transition Zone (Flagstaff, higher elevations): Warm-season grass is less common here due to shorter summers. If you attempt it, planting in early June is essential, but success is not guaranteed with frost risks.
Checking Your Soil Temperature
Don’t just guess. Use a simple soil thermometer from any garden center. Take the temperature at a 1-inch depth in the morning for an accurate reading. Consistently readings above 65°F mean it’s time to go.
Choosing Your Summer Grass Seed
Not all grasses perform the same in Arizona’s arid heat. Here are the top contenders known for there durability and water efficiency.
- Bermudagrass (Common or Hybrid): The most popular choice. It’s tough, spreads quickly, and handles heat and foot traffic very well. It does require full sun and can be invasive in flower beds.
- Zoysiagrass: A great alternative. It’s more shade-tolerant than Bermuda and forms a dense, weed-resistant turf. It establishes slower and may need less frequent mowing.
- Buffalograss (for low-water use): A native option that requires significantly less water once established. It has a fine, gray-green texture and is best for low-traffic areas.
Step-by-Step Lawn Seeding Guide
Follow these steps carefully after you’ve hit the right planting window.
1. Prepare the Soil
This is the most overlooked step. Remove all weeds, rocks, and old grass. Loosen the top 2-3 inches of soil with a rake or tiller. If your soil is heavy clay, mix in 2-3 inches of compost to improve drainage and help with water retention. Level the area to prevent puddling.
2. Apply the Seed
Check the seed bag for the recommended Arizona seeding rate. Using a broadcast spreader helps ensure even coverage. For best results, sow half the seed walking north-south, and the other half walking east-west. This technique prevents streaky results.
3. Cover and Protect the Seed
Lightly rake the area so about 1/4 inch of soil covers the seeds. Then, apply a thin layer of weed-free straw or peat moss. This covering retains crucial moisture and protects seeds from birds and wind.
4. Water Correctly
Watering is non-negotiable for germination. Your goal is to keep the top inch of soil consistently moist, but not soggy.
- First 10-14 days: Water lightly 2-3 times per day for very short periods (5-10 minutes).
- After germination: Reduce frequency but increase depth. Water less often but for longer to encourage deep roots.
- Once established: Transition to a deep, infrequent watering schedule common for Arizona lawns.
5. First Mow and Ongoing Care
Wait until the grass reaches about 3 inches tall for its first mow. Never cut more than one-third of the blade height at once. Begin a fertilization program about 4-6 weeks after germination with a slow-release fertilizer formulated for summer grasses.
Common Mistakes to Avoid
- Planting too early: Cool soil leads to slow germination or seed rot.
- Planting too late: Seedlings fry in peak summer heat before roots develop.
- Overwatering: This causes fungal disease and shallow roots.
- Using the wrong seed: Avoid cool-season grasses (like ryegrass or fescue) for a permanent summer lawn—they can’t survive the heat.
- Skipping soil prep: Seed-to-soil contact is vital for germination success.
FAQ: Planting Grass in Arizona
Can I plant summer grass in the fall in Arizona?
No. Fall soil temperatures are cooling, which prevents warm-season grasses from germinating properly. Fall is the time to overseed with winter ryegrass into an existing Bermuda lawn if you want winter green.
What is the most drought-tolerant summer grass for AZ?
Buffalograss is the most drought-tolerant native option. For a traditional lawn, certain varieties of Bermudagrass and Zoysiagrass, when established properly, are also quite water-efficient compared to cool-season grasses.
How long does it take for Bermuda seed to germinate in Arizona?
With proper warmth and moisture, Bermudagrass seed typically germinates in 7 to 14 days under ideal Arizona spring/summer conditions.
Is it better to seed or use sod?
Seeding is far more cost-effective for large areas and offers more variety. Sod provides an instant lawn and is less vulnerable to weeds during establishment, but it is much more expensive and still requires careful timing for installation in the warm season.
Can I just throw grass seed on my existing lawn?
This rarely works for establishing a new lawn. Existing thatch and grass will prevent seed-to-soil contact. For overseeding thin areas of the same grass type, thorough aeration and scalping are required first. For a complete lawn renovation, starting from bare soil is best.
By following this optimal timing and method, you give your summer lawn the foundation it needs to thrive through Arizona’s toughest season. The key is patience and working with the climate, not against it. With the right start, you’ll have a resilient lawn that can handle the heat.