Apart from the decision you make as to when your lawn needs the water, you also need to make a decision as to what time of day is the best. For many that will be decided by when you are around to do it, but with automatic watering systems available freely nowadays, that is not so much of an issue.
The best time of day to water your lawn is when it is most effective and efficient to do so. It could be inefficient to water at the hottest part of the day. Your lawn watering efforts would be least effective. At the hottest part of the day, the water will have little time to penetrate, as it will tend to evaporate off most quickly. The air itself will be hot and it will suck the cool water off your grass quite quickly, so some of your effort is wasted, as is your water.
So, it is often best to water when the air is cooler, which means the morning or evening, both of which work OK. One thing you have to be aware of is that if you do your lawn watering in the evening, the grass will stay moist for longer, but this will also help fungal growth, which is greatest at night. In the long run this can affect your lawn development.
If you can, carrying out your lawn watering in the morning is probably the best, with midday the next. Leaving evening watering as the last option if you want to avoid providing fungal infections with their best chance to thrive.
Bear in mind that with water restrictions all over the world from time to time, even in the Western world, you may not be as free to water as you might wish. Taking care to water only when necessary and when you do, when permitted, making sure that you do it as effectively and economically as you can, is doing your share for the environment too.
Lawn watering is a necessary ‘must do’ to give you the pleasure of a lovely lawn, as well as ensuring the health of your grass, for years to come too.
(c) 2007 Lawn Care Guidelines. All you need to know to make the right decisions to get a great looking lawn. There’s all the information you could ask for, at Martin Haworth’s website, http://www.LawnCareGuidelines.com