In the morning.

Morning is a good time to water. There are benefits to letting your soil dry very well on occasion between waterings. This helps to break down some of the minerals locked up in the soil. I probably should relay some other interesting information which correlates. Plants tend to "open" their system in the cooler parts of the day, especially in the morning. The "inhale" and "exhale", the exhange of gasses and nutrients often takes place then. This is a great time to foliar feed. There is no better approach to helping plants grow than an organic program...after all, it is organic just like you. Organic substances such as a compost tea (often composted manure based), liquid kelp (seaweed), some mollasses, mixed together and sprayed on plants at this time of day (or in the late evening if you can't make the morning) go an incredibly long way towards healthier and "happier" plants. Beneficial microbes (which feed and protect plants) are promoted with this mix. It strengthens the plant structure so it can better wwithstand times of stress, and inhibits pests and antagonistic insects or disease. Just like a human, the more naturally balanced and healthier the system, the better it can fend off disease. The mix is usually ounces in ratio 8-1-1 respectively for the compost tea (made by just putting the compost in a bucket and filling with water...strain/screen off your tea), molasses, liquified seaweed. From this mix, apply "one or two ounces" per gallon of water on your sprayer dial setting. ...but anyway...a point here is that plants are more receptive in their ability to intake nutrients during the cooler, less stressful part of the day. There is an additional factor: Plants being a life form, prefer aesthetic "atmospheres" or pleasing environments. The aesthetic morning sounds tend to "open" foliage. Birds and chirping and morning life sounds. Music (aesthetic type) does a similar type thing. Life gravitates towards the aesthetic, towards higher qualities such as affinity and appreciation. American Indians were know for their appreciation of nature and were in tune to it...and actually received some remarkable results. People who talk to their plants get good results. And, plants like to be of use...that is, to have a value such as for food or beauty or helping other life forms. I know...it sounds a little weird or "hippie esoteric". But the point here is that in the morning, there are often more aesthetic qualities which also help plants to open up. By the way, synthetic fertilizers (and Miracle Grow is a major one) and other synthetic, unnatural chemicals impede the natural balance of plants. If a person tries to mix practices with synthetic and some organic, the synthetic approach often inhibits organic results. It is easy to discover "WHY" when you research what synthetics actually do to life forms.

If you have a timer and a sprinkler system, you should set you timer for 4:30 a.m. At this time in the early morning you will have the least amount of evaperation. Depending on where you live, you should set your timer from 15-20 minutes. You should also water every 2 to 3 days.

Evening after the heat of the sun has gone down.

Early in the morning. If you water late in the evening the water will sit on your grass blades and can lead to fungus and other diseases. If you water in the middle of the day during the hot sun you lose alot of the water to evaporation and you risk scalding your grass. In the morning before the heat sets in allows the water to sink deep down into where the roots are and gives the blades time to dry.

Early a.m. before the hot sun comes up.

Late after the sun goes down - That's how we do at the Golf Course

i've always been told either, early morning or late evening, Just as long as when they are wet the sun doesn't beat down on them and burn them up.

Evening I have found to be the best time that way the water has all night to soak into the ground before the sun comes up. I have found that by watering early in the morning when the sun comes up there seems to be alot more evaperation.

depending on your area , the time of year and the amount of normal humidity in the air. at night, early morning or late in the evening is the best times.. but some times like night may cause mildew etc on plants depending on your climatic area...check with a nurseryman in your area

THE COOLEST PART

When the sun has just set.

Early morning.