A lawn that needs less water starts with the right grass and the right amount of seed. This drought-tolerant lawn seed calculator tells you how many pounds of seed to buy to start a new lawn, patch bare spots or overseed an existing lawn, using typical seeding rates for four grasses known for coping with dry weather: tall fescue, fine fescue, hulled Bermudagrass and buffalograss. It works in square feet and pounds, like the other tools on the site.
Grass seed is sold by the pound, and the rate on the bag is given per 1,000 square feet. The calculator scales that rate to your lawn, adds a small spare for uneven spreading and shows the rate it used, so you can compare it with the label on the bag you are about to buy.
How to use the drought-tolerant lawn seed calculator
- Enter your lawn area in square feet. Multiply length by width for each section, subtract beds and paths, and add the sections together.
- Choose the grass type. The list includes two cool-season grasses, tall fescue and fine fescue, and two warm-season grasses, hulled Bermudagrass and buffalograss. The next sections explain which suits your region.
- Choose the project. Pick a new lawn or bare patches for the full rate, or overseeding an existing lawn for the lighter rate.
- Read the results. You get the pounds of seed needed, the seeding rate used and the amount with 10% spare.
The figures are typical rates. Seed varies in size and coating, and your bag may recommend a different amount, so the label on the bag you buy always takes priority.
The grass seed math
The calculation scales the seeding rate from 1,000 square feet up to your lawn.
Seed needed (lb) = lawn area (sq ft) ÷ 1,000 × seeding rate (lb per 1,000 sq ft)
Seed with spare (lb) = seed needed × 1.1
Worked example: a new tall fescue lawn
You are seeding a new 3,000 square foot lawn with tall fescue at 7 pounds per 1,000 square feet. The seed needed is 3,000 ÷ 1,000 × 7 = 21 pounds. With a 10% spare for uneven spreading, that is 23.1 pounds, so two 12 pound bags or one 25 pound bag would cover it.
Worked example: overseeding the same lawn
Overseeding a thin existing lawn of the same size takes half the new-lawn rate, 3.5 pounds per 1,000 square feet. The seed needed is 3,000 ÷ 1,000 × 3.5 = 10.5 pounds, or about 11.6 pounds with spare.
Worked example: a Bermudagrass lawn
Hulled Bermudagrass seed is very small, so the rate is much lighter, at 1.5 pounds per 1,000 square feet for a new lawn. A 5,000 square foot lawn needs 5,000 ÷ 1,000 × 1.5 = 7.5 pounds, and 8.25 pounds with spare.
Typical seeding rates
The calculator uses these rates, in pounds of seed per 1,000 square feet:
- Tall fescue: 7 for a new lawn, 3.5 for overseeding
- Fine fescue: 4.5 for a new lawn, 2.5 for overseeding
- Hulled Bermudagrass: 1.5 for a new lawn, 0.75 for overseeding
- Buffalograss: 2 for a new lawn, 1 for overseeding
These are typical, not universal. Coated seed, which is covered with a material that holds water or fertilizer, weighs more per seed than bare seed, so a bag of coated seed may call for a higher rate by weight. Always check the rate on the label.
What drought-tolerant really means
No lawn grass lives on air. A drought-tolerant grass is one that survives dry spells by growing deep roots, going dormant, or both, and that recovers when rain returns. A dormant lawn turns tan and stops growing, then greens up again when water is available, which is a normal survival strategy and not a sign the lawn has died. Choosing one of these grasses cuts the water a lawn needs, but a new lawn still needs regular watering until it is established, and no grass looks its best in a long drought without any water.
Choosing the right grass for your climate
The most important choice is between cool-season and warm-season grasses, and the answer depends on where you live. Cool-season grasses grow best in the cooler weather of spring and fall and dominate the northern half of the country. Warm-season grasses grow best in summer heat and dominate the South. In the transition zone between them, either type may work. Look up your climate with our growing zone finder and ask your local extension service which grasses do best nearby.
Tall fescue
Tall fescue is a cool-season grass with deep roots, and it handles heat and dry spells better than other cool-season lawn grasses, such as Kentucky bluegrass. It forms a coarse, dense lawn and holds up to foot traffic. It is a leading choice in the transition zone and in much of the northern half of the country. It is usually mowed fairly high, around 3 to 4 inches.
Fine fescue
Fine fescues, including creeping red, chewings and hard fescue, are cool-season grasses with fine leaves. They need less water and less fertilizer than most lawn grasses and tolerate shade, which makes them useful for shady, low-maintenance lawns. They do not hold up well to heavy foot traffic.
Hulled Bermudagrass
Bermudagrass is a warm-season grass that thrives in heat and full sun. It goes dormant and turns tan in cold weather, and it spreads aggressively once it is established. Hulled seed, which has had the outer coat removed, germinates faster than unhulled seed and is the type most often sold for lawns. It does poorly in shade.
Buffalograss
Buffalograss is a warm-season grass native to the Great Plains. It needs very little water and fertilizer once established, and it is sometimes left unmowed or mowed only a few times a year. It grows slowly, so weeds can be a problem while it fills in, and it is not suited to shade or heavy traffic.
When to seed
Timing matters more than any other factor in getting seed to take. The rule is simple: seed when the grass wants to grow.
- Cool-season grasses (tall fescue, fine fescue): early fall is best, because the soil is still warm for germination and the cool, moist weather is gentle on seedlings. Spring is the second best time, but summer heat and weeds are tougher on young grass. If you are reading this in late October, the window in many northern areas is closing, and a spring seeding may be the better plan.
- Warm-season grasses (Bermudagrass, buffalograss): late spring through early summer, once the soil has warmed. These grasses germinate poorly in cool soil, so fall seeding is not recommended.
Check your first frost date with the frost dates by ZIP code tool and plan around it.
How to seed a lawn
- Test and prepare the soil. A soil test tells you the pH and nutrient levels. Remove weeds and debris, and loosen the top few inches. If the soil is poor, work in compost. Our soil calculator and compost calculator help you work out how much.
- Level the surface. Fill low spots and rake the soil smooth. Water pools in hollows and washes seed away.
- Spread the seed evenly. A broadcast spreader gives the most even coverage. Put down half the seed walking one direction and the other half crosswise.
- Press the seed into the soil. Seed needs contact with soil to germinate. Rake lightly so the seed is barely covered, and roll or walk over the bed. Most grass seed should be covered by no more than about a quarter inch of soil.
- Add a thin mulch. A light layer of clean straw holds moisture and protects seed from birds. It should be thin enough that you can still see soil through it.
- Feed with starter fertilizer. A starter fertilizer is higher in phosphorus, which helps young roots. Some states restrict phosphorus, so check local rules. Our fall lawn fertilizer calculator shows how to work out the right amount of any fertilizer.
Watering new seed and building drought tolerance
New seed needs steady moisture. Keep the surface of the soil evenly damp, with light watering once or twice a day in dry weather, until the seedlings come up. Do not let it dry out, and do not flood it. Once seedlings are growing, water less often and more deeply, so roots chase moisture downward. Deep, infrequent watering is how a lawn becomes drought-tolerant, because shallow, frequent watering trains roots to stay near the surface. The garden watering calculator can help you work out how much water an area needs.
Wait to mow until the new grass is tall enough, usually about a third higher than the mowing height, and never cut off more than a third of the leaf at a time. Keep foot traffic off the new lawn until it has been mowed a few times.
Other ways to cut your lawn’s water use
The grass you choose is only part of the picture. A few habits cut water use on any lawn. Mow high, since taller grass shades the soil, keeps roots cooler and holds moisture, and leave the clippings on the lawn, where they return nutrients. Aerate compacted soil in the right season, so water soaks in and does not run off. Go easy on nitrogen, because heavy feeding pushes lush growth that needs more water. Water early in the morning, when less evaporates, and water deeply and rarely, not a little every day.
You can also shrink the lawn. Strips that are hard to water, such as steep slopes, narrow areas along driveways and shady corners under trees, often do better as mulched beds, groundcover or native plantings. Keeping grass only where you use it, for play, walking and open space, cuts the area that needs seed, fertilizer and water, and it gives you less to mow.
Reading a grass seed label
The bag has the information you need to compare products. The label lists the grass species and varieties in the mix, the percent germination, which tells you how much of the seed should sprout, the percent of inert matter such as filler and coating, and the percent of weed seed and other crop seed, which should be very low. Avoid mixes with a high percentage of other crop seed or any noxious weeds. A bag with higher germination and lower inert matter gives you more live seed per pound, which can make a cheaper bag the more expensive option.
Common lawn seeding mistakes
- Seeding at the wrong time. Cool-season grasses in summer or warm-season grasses in fall seldom do well.
- Not pressing the seed into the soil. Seed lying on top dries out and blows away.
- Letting new seed dry out. A single dry day can kill germinating seed. Keep the surface damp.
- Burying the seed too deep. Grass seed is small, and deep seed may never reach the surface.
- Using too much seed. A thick stand is crowded, weak and prone to disease. Follow the rates.
- Choosing the wrong grass. A cool-season grass in a hot southern summer, or a sun-loving grass in a shady yard, will struggle.
- Using weed killer too early. Many herbicides harm new seedlings. Check the label and wait until the grass is established.
Frequently asked questions
How much grass seed do I need for 1,000 square feet?
For a new lawn, typical rates are about 7 pounds of tall fescue, 4.5 pounds of fine fescue, 1.5 pounds of hulled Bermudagrass and 2 pounds of buffalograss. For overseeding, use about half those amounts.
What is the most drought-tolerant lawn grass?
It depends on your climate. Among cool-season grasses, tall fescue handles dry spells best. In warm climates, Bermudagrass and buffalograss are among the most drought-tolerant lawn grasses.
When is the best time to seed a lawn?
Early fall is best for cool-season grasses, with spring second. Warm-season grasses should be seeded in late spring or early summer when the soil is warm.
Can I overseed in late fall?
It is risky. Seed sown too late may not germinate before winter, and some will wash away or be eaten. In many northern areas, spring is the safer choice if you have missed the early fall window.
How long does grass seed take to grow?
It varies with the grass and the weather. Perennial ryegrass sprouts in a week or so, tall fescue often takes one to three weeks, and slower grasses such as buffalograss can take longer. Warm soil and steady moisture speed things up.
Do I need to rake after spreading grass seed?
Yes, lightly. Raking presses the seed into contact with soil, which is what it needs to sprout. Cover it with no more than about a quarter inch of soil.
Why does my drought-tolerant lawn turn brown in summer?
It may be dormant, which is how many drought-tolerant grasses survive dry spells. A dormant lawn turns tan and recovers when water returns. If it stays brown after rain, the grass may have died, and you can check by tugging gently on the blades.