Water Conservation in Turf
Life would not be possible without water.
Water is essential for seed germination and plant growth, and can make up >75% of the fresh weight of actively growing turfgrasses.
Fresh water can be found underground in aquifers, which are geological formations of rocks, sands and gravels. Groundwater is recharged mainly from rain and snowmelt seeping into the ground. We must protect our water from overexploitation – extracting more water than is replaced by rain and snow. Lawns and grassy areas often come under criticism when it comes to water use. However, we can find a balance between the inputs needed and the beneficial services offered by turf by using sustainable management practices.
In an urban setting, grassed areas reduce dust, offer spaces to entertain and play, and can cool the surrounding area by 5-10°C. Lawns around buildings offer fire prevention, security (visibility) and control of pests like fleas, ticks, and rodents. Compared to hardscape surfaces like concrete, asphalt, and paving stones, the speed of water flowing over grass is significantly slowed down which is important for stormwater management. Slower moving water can thus be absorbed into the soil to recharge the groundwater aquifers.
Additional benefits of turf include:
- Carbon sequestration
- Noise reduction
- Increased property value
- Soil erosion control
During the summer, especially when conditions are dry, grass typically goes into a state of semi-dormancy. The plants will slow their growth and focus their energy on keeping their crown and roots alive. Semi-dormant turf turns a toasty brown or yellow colour, and might look dead. However, the plants are in a state of waiting, and can remain in this condition for up to 6 weeks before dying! Most lawns in Ontario are seeded with a mixture of Kentucky bluegrass and perennial ryegrass, which will be able to survive the heat of the summer without water until the cooler, wetter conditions return in the fall.
Some tips for summer water conservation:
- Allow your lawn to go brown in the summer. If you're worried that the turf is dead, you can gently tug at the plants. If the roots hold tight, then they are still alive and will green up when given some water.
- Avoid walking or playing on dormant grass.
- If you choose to water, do it INFREQUENTLY. Water so that the soil is wet to the maximum root depth (use a shovel to check how deep that water went).
- Water based on weather conditions. Allow for your turn to show some drought symptoms (leaf rolling, foot prints show up easily) before watering again.
- Check your property for "hot spots" - areas which might need more watering than others. This might be due to more sun, compaction, or tree roots in certain areas.
- Keep the lawn tall during the summer to encourage deeper rooting. Never cut more than 1/3 of the plant off during any mowing event.
- Sharpen your blades! Dull mower blades can cause ripping and tearing which is more stressful to the turf.
- Leave the grass clippings on your lawn. Grass clippings break down quickly and return beneficial nutrients and moisture to the soil.