Planting a new lawn from seed can be a satisfying project, but it requires extra care and attention in the first few weeks to ensure the grass seeds germinate and establish successfully. Proper watering is crucial during this time, as grass seedlings have very short roots and need constant moisture to grow. Here are some tips on how often and how much to water newly planted grass seed.
Water Lightly and Frequently at First
When you first plant grass seed, the seeds need to be kept moist constantly to germinate. At this early stage, avoid heavy watering that can wash away the seeds. Instead, aim to keep the top 1-2 inches of soil moist. The easiest way to do this is by watering the area lightly but frequently:
Water newly planted grass seed 2-3 times per day for the first 1-2 weeks.
Each watering session should last 5-10 minutes. Adjust duration as needed to wet the soil without puddling or runoff.
Water in the early morning, afternoon, and evening to replenish moisture lost to evaporation and sun exposure during the day.
Use a sprinkler, hose end sprayer, or other gentle watering method. Avoid heavy pressure from direct hoses that can displace seeds.
The frequent light watering maintains moisture in the germination zone so the grass seeds can take up water and nutrients to sprout and develop roots.
Gradually Water Deeper and Less Often
After the first 1-2 weeks and once the seeds have germinated, you can begin to water less frequently but more deeply. This encourages the grass plants to develop deeper root systems.
Water every 2-3 days, cutting back to just 1-2 watering sessions per day.
Run each watering cycle long enough for moisture to penetrate 4-6 inches deep into the soil.
To check depth, dig a small hole and inspect how far down you see a darkening of soil color from water saturation.
As the grass plants mature over 2-4 weeks, gradually increase your watering depth to 6-8 inches.
The longer intervals between watering sessions also force the roots to reach deeper for available water rather than staying near the surface.
Adjust Frequency Based on Weather and Soil Type
The ideal watering frequency ultimately depends on the weather conditions and your soil type:
- Hot, dry, or windy conditions cause faster evaporation from the soil, so you’ll need to water more often. Cool, calm weather allows you to water less frequently.
- Sandy soils drain quickly and require more frequent watering than loamy or clay soils that hold moisture longer.
- Inspect the lawn each day. If the grass blades are folded, wilted, or show footprints that remain compressed, it’s time to water again.
- Probe the soil with your finger. If the top few inches are dry, the lawn needs more water, even if you watered recently.
- Adapt your schedule accordingly, increasing frequency during hot, dry spells and cutting back during cool, damp weather.
When to Stop Daily Watering
You can scale back to a typical lawn watering routine when the new grass is well established, typically after the first 4-6 weeks. Signs the lawn is ready for less frequent deep soakings:
- Grass blades are longer and fuller, forming a dense lawn.
- Grass stems are visibly thicker and anchored by deeper roots.
- Much of the initial watering is to keep seeds moist. Once grass is up, 2-3 deep soakings per week are sufficient.
- Weather is cooler and moister, reducing plant and soil water loss.
Don’t quit watering altogether, though. New lawns still need about 1-1.5 inches of water per week from rainfall or irrigation during the rest of the first growing season.
With attentive, properly timed watering matched to the lawn’s evolving needs, you can keep new grass seed consistently moist for successful germination, establishment and vigorous growth.