Watering your lawn at night offers the main benefit of reduced evaporation; you conserve water while maximizing your turf’s absorption ability without the sun’s constant heat. Watering at night, however, can encourage disease in a poorly managed lawn. Although healthy turf may not have obvious disease issues from nighttime watering, irrigation should occur during morning to avoid possible grass damage over time. Whether it is best to water lawn in morning or afternoon depends on the time of year.
Ideal Timing for Watering the Lawn
During spring and summer, lawns must endure afternoon heat stress because most grass species grow best in full-sunlight locations. Help your grass endure the long, afternoon sunlight by irrigating your lawn in early morning. Evaporation loss is minimal because wind and sunlight are limited at that time of day. Also, plants absorb water faster in morning than during afternoon.
The absorbed water helps grass retain its green hue and upright posture throughout the day. Watering lawn in morning or afternoon is helpful during the colder months because if a particularly cold night is ahead, daytime watering allows time for the moisture to move into the soil to protect the grass from frost damage.
Disease and Lawn Watering Schedule
Many bacterial and fungal diseases rely on wet foliage for reproduction and to spread. If you water lawn at night in summer, the lack of evaporation provides time for the pathogens to infiltrate your grass. Morning watering allows time for evaporation and soil absorption, keeping foliage dry overnight.
Overwatering any time of day, however, causes major lawn problems. For example, soggy soil reduces oxygen supplies and causes grass stress. As a result, pathogens, such as root rot, set in and damage the lawn until you correct the soggy conditions. In general, water infrequently to a 6-inch soil depth each time; watering a little bit each day only encourages shallow roots that succumb to drought stress and possibly disease.
Water Lawn Morning or Night to Prevent Pests?
Pests use nighttime to invade a lawn while unseen. As you water your lawn in morning, you have a chance to remove the pests, such as snails, to prevent widespread turf damage. As grass blades swell with moisture, they are more difficult for small pests to damage; wilting grass blades allow simple access to their internal areas upon which pests feed. Morning irrigation efforts keep grass strong for natural pest resistance, which means you don’t have to rely on spraying harmful pesticides across your yard.
Watering for Effective Turf Management
Compacted soil and a thick thatch layer of decaying stems and foliage hinder water absorption and may contribute to puddling on grass turf’s surface. Nighttime watering of a lawn with poor soil often suffocates grass roots and invites disease to the moist areas. Aerating soil by removing 1- to 2-inch long soil cores from the ground rejuvenates grass by providing better access to moisture and oxygen.
Aerated soil reduces puddling and disease while moving precious water into lower areas of soil where roots can absorb the water. Aeration also reduces the thatch layer, allowing healthy water absorption during morning irrigation.