Lawn watering

June 26, 2005 5:13 AM

Is there a specific amount of time I should wait between mowing my lawn and watering it to prevent damage to the lawn?
posted by y0mbo to Home & Garden (6 answers total)

I'm not an expert, but here's something that might help, since nobody else has contributed.

I've heard that it's bad to water a lawn on a really sunny day, as the water droplets will direct the sunlight and will burn/kill the grass. Because most mowing in the summer happens at sunny parts of the day, you might want to wait until the sun is less oppressive to water the lawn. Maybe cut it in the morning, then water it that evening?

As far as injury to the grass from water on the freshly-cut blades, I've never heard that there'd be problems with that. But, again, I'm no expert at lawncare.
posted by Alt F4 at 10:28 AM on June 26, 2005

The main reason for not watering on a really sunny day is that a lot of the water goes to waste - it just evaporates before it gets to the roots.


As to the original question, you can water your lawn immediately after mowing and it won't cause any damage. The problems come up if you water it first - a lawnmower doesn't cut a wet lawn very well - instead of shearing the grass blades, it tears them. Always water a lawn when it's dry (run your hand over it and if your hand stays dry, it's OK to mow).
posted by gwenzel at 10:43 AM on June 26, 2005

I've taken to watering my lawn once a week, twice at most if I feel it really needs it. I do a very deep watering on those days. I used to do several times weekly to daily short waterings, but I've since moved to this method. I water most every monday morning for 15 minutes followed by 25 minutes. The first is sort of a pre-watering, to make the ground moist and more receptive, a bit like how a partly damp sponge absorbs water better than a fully dry one, which has water just run off.

The goal of watering like this is to keep the dirt moist below the surface, but keep the top few inches fairly dry. This a) keeps weeds out, since weeds prefer to grow in the top few inches and b) makes grass roots grow deep to find water instead of spreading out and creating thatch.

This is not an entirely direct answer to your question, but I'm getting there. My point is that you should water only when the lawn *needs* it. It's fairly easy to tell. The grass changes color a bit, and when you walk through it, it does not spring back as readily (depending on the variety you may actually leave footsteps).

There is no particular reason I can think of why you can not water your lawn directly after mowing, BUT, the best time by far to water is in the early morning. Watering during the day causes a significant amount of water to evaporate before getting absorbed deep into the soil. Watering at night sometimes causes too *little* to evaporate, keeping the shallow roots wet and causing some kinds of fungus to grow and attack the roots. Early morning waterings are best.

The above probably sounds fairly labor intensive and it probably would be if you're watering by hand. I water with an irrigation system so I don't find it too onerous. I check it every other morning or so and start the sprinklers on my way to work if it looks like it needs it.
posted by RustyBrooks at 12:12 PM on June 26, 2005

Praise AskMeFi and RustyBrooks. We just laid sod (like, finished an hour ago), and your watering tips are just what we need to know.
posted by 5MeoCMP at 3:46 PM on June 26, 2005

Not sure if it helps at all with your question, but on the subject of lawncare, I'm quite fond of this page.
posted by sublivious at 6:02 PM on June 26, 2005

Thanks, sublivious -- that's great!
posted by languagehat at 7:13 AM on June 27, 2005