During a long, hot summer, you might think it's impossible to give your lawn too much water. However, overwatering can have effects that are just as devastating as underwatering. Don't make the mistake of thinking that any problem with your lawn can be solved by simply turning on the sprinklers for more time each day. Instead, consider the type of grass on your lawn, the type of soil it is growing in, and the local climate conditions to work out exactly how much water you should give.
If your lawn is seeded with a drought-tolerant grass variety, such as fine fescue or zoysiagrass, you don't need to supply as much water as you would for a thirstier variety, such as St. Augustine grass, which thrives in wet conditions. If you're seeding a lawn from scratch or purchasing new turf supplies, it is worth paying attention to the type of grass you are putting down so you know whether overwatering or underwatering is likely to be your biggest concern.
The average lawn needs about 2.5 cm of water every week, but the type of soil can make a difference in how you should apply this water. Sandy soil drains quickly, so applying a lot of water in one go is unlikely to harm your lawn. However, clay soils can take as long as five hours to absorb a mere 2.5 cm of water, so to avoid subjecting your grass to boggy conditions, you should apply the water at a slower rate.
Signs of Overwatering
If you can see puddles of water stagnating on your lawn, it should be obvious that conditions are getting just a little too wet. However, before you get to this point, there are some more subtle signs of overwatering that you can watch out for. You may notice mushrooms or other fungi starting to appear in your lawn as well as a rapid growth of weeds. The lawn may also start to develop a dense mat of decomposing plant material on its surface; this is known as thatch. If you see thatch on your lawn, you need to remove it with a rake and reduce the amount of water you supply each week to prevent it coming back.
By looking out for signs of overwatering and only giving your grass as much moisture as it needs to thrive, you can ensure your lawn stays healthy and lush all year round.