How to Water Your Lawn in Delaware

An established Delaware lawn needs about one inch of water per week, from rain and irrigation combined. Water deeply once or twice a week in the early morning instead of sprinkling a little every day. Deep, infrequent watering pushes roots down, and deep roots are what carry cool-season grass through a dry August.

This guide covers how much, how often and when to water in Wilmington and the rest of New Castle County, how long to water new seed and sod, and how to keep a lawn alive when dry weather hangs on.

How much water does a Delaware lawn need?

Most Delaware lawns are cool-season grasses such as tall fescue and Kentucky bluegrass. In active growth they need roughly one inch of water a week. In the hottest weeks of July and August, a lawn can use more than that.

To measure one inch, set a few empty tuna cans or straight-sided containers around the yard and run your sprinkler until they fill to the one-inch line. Note how many minutes that takes, then use that run time as your baseline. Count rainfall too. A half inch of rain on Tuesday means you only need to add half an inch by hand.

If water starts running off the lawn or into the street before you reach an inch, stop, wait 30 minutes for the soil to absorb it, and finish the cycle. Runoff wastes water and carries fertilizer toward storm drains.

What is the best time of day to water a lawn?

Water before sunrise or in the early morning, ideally between about 4 a.m. and 9 a.m. Cooler air and light wind mean less evaporation, and the blades dry in the morning sun. That lowers the risk of the fungal diseases that thrive on grass left wet overnight in humid Delaware summers.

Avoid watering in the evening. Grass that stays wet all night is the setup for brown patch and other lawn diseases.

How often should you water in spring, summer and fall?

Frequency depends on weather, soil and sun, so check the lawn instead of following a calendar.

• Spring and fall: rain usually covers most of the need. Add water by hand only after a week with less than an inch of rain.
• Summer: expect to water once or twice a week during dry stretches, giving the full inch across those sessions.
• Clay soil common around Wilmington holds water longer but absorbs it slowly, so split the inch into two sessions to avoid runoff.

Two quick tests tell you when the lawn is ready for water. Walk across it and look back: if your footprints stay flat instead of springing back, the grass is stressed. Or push a screwdriver into the soil. If it will not go in easily, the soil is dry and compacted.

Watering too often is as harmful as too little. Daily light watering keeps roots shallow, encourages weeds, builds thatch and invites disease.

How long should you water new sod or grass seed?

New lawns follow a different schedule because roots have not formed yet.

• New seed: keep the top inch of soil moist, never soggy, with short watering sessions once or twice a day until the seed sprouts. Once the grass is about an inch tall, taper to longer, less frequent watering.
• New sod: water daily for the first one to two weeks so the soil under the sod stays damp. Tug a corner after two weeks. When it resists, the roots have taken hold and you can move to deeper, less frequent watering.

Timing matters as much as watering. In Delaware, early fall is the best window to seed or lay sod, because soil is warm and air temperatures are mild. Our aeration and overseeding service is built around that window.

How do you keep a lawn green during dry weather?

A week of hot, dry weather can pull a lot of moisture from a lawn, and a long drought can set it back for the rest of the year. These steps help.

1. Mow higher. Cutting tall fescue and bluegrass at three to four inches shades the soil and slows evaporation. See our guide to the best mowing methods.
2. Aerate and remove thatch. Core aeration and dethatching open paths for water to reach the roots, so even a small amount of rain or irrigation gets used.
3. Reduce traffic. Walking, playing and running on stressed grass damages it faster than usual.
4. Capture rain. A rain barrel under a downspout gives you water for trees, shrubs and beds. Keep barrels covered so standing water does not breed mosquitoes.
5. Plant for drought. Drought-tolerant plants in beds cut your overall water use even when there is no drought.

If rain stays away for weeks, a cool-season lawn may go dormant and turn tan. Dormant grass is not always dead. Watering it lightly every two to three weeks, about a quarter to a half inch, keeps the crowns alive until rain returns. When the weather breaks, resume deep watering and avoid heavy fertilizer until the lawn is growing again.

Can an irrigation system do this for you?

A properly zoned system with a timer applies water at the right hour and the right amount without you standing at a hose. A clogged head or uneven coverage causes the dry patches and soggy spots that many homeowners blame on the grass. Green Acres designs, installs and services irrigation systems for Delaware homes and commercial properties. If your lawn keeps browning in the same places no matter how you water, our lawn and plant health service can help look for the cause.

Frequently asked questions

How many days a week should I water my lawn in Delaware?

Most established lawns do best with one or two deep watering sessions per week that add up to about one inch, rainfall included. In spring and fall, rain often covers it. Use the footprint test or a screwdriver to decide instead of watering on a fixed schedule.

What time of day is best to water grass?

Early morning, before about 9 a.m. and ideally before sunrise, is best. Water soaks in before heat builds, and the blades dry during the day. Evening watering leaves grass wet overnight, which raises the risk of fungal disease.

How long should I water new grass seed?

Keep the top inch of soil moist with short sessions once or twice a day until the seed sprouts. When the new grass is about an inch tall, water less often but longer so roots grow deeper.

Should I water a brown lawn during a drought?

A cool-season lawn that turns tan in a drought is often dormant, not dead. Light watering of a quarter to a half inch every two to three weeks keeps the crowns alive. Resume normal deep watering once the weather cools or rain returns.

Request a free estimate from Green Acres or call (302) 332-8239 and tell us what is happening in your yard.