lawn watering

by kate
(Kankakee, Illinois, USA)

I live in Zone 5, in Illinois. We have an irrigation system, and my question is , what is the appropriate (approx.) time and amount of water necessary to keep the lawn nice? How often, how much water?

Doug says - in general about one inch a week will keep the lawn green if you have decent topsoil underneath it. This assumes a 2-inch mowing height (the top of your mower setting)

If you have typical suburban sand fill, it's going to take up to 2" a week. You can measure this by putting a water collector (like a yogurt container) under the sprinkler pattern and timing how long it takes to fill one inch on the container). It might take 15 minutes, it might take an hour depending on your sprinkler setup. So you have to watch it carefully the first time you water. Stop watering after you hit an inch.

Buy a timer.

Water this length of time once a week. Not twice but once. And control the output by using the timer. Watering once keeps the plants alive but forces them to develop deep roots to reach all the water. Freguent watering encourages shallow root development (not a great thing for hardiness and performance in grass).

Do NOT set it on automatic. This eliminates the need to water if you've had a rainy week and the obvious sight of sprinklers running during a rainstorm. (which you'll have to admit is a bit of overkill and waste of water)

Get an inexpensive water measuring cup (mine cost .99) and leave it on the edge of the garden where you won't mow it. Check it after a rain to see how much natural rainfall has landed. You can adjust your own irrigation depending on how much you've received from Mother Nature.

Do irrigate first thing in the morning before the sun can evaporate the water or you'll lose 50% of your water to evaporation. By first thing, I mean around 6am so the watering is well finished by 7am and the time the sun starts to dry out the gardens. Watering at noon is an invitation to water evaporation. Watering at evening is second best but never recommended because of potentially encouraging fungal infestations due to wet and dark conditions. First thing in the morning it is.

Hope that helps.