Depends on your climate and weather, as well as the type of plants. I wouldn't do it to tomatoes or any curcurbits as they are extremely susceptible to diseases and fungi that just love moist conditions at nighttime temps. Lettuce is probably fine disease wise, but the slugs would have a field day. I know this isn't a welcomed answer, and you might never have a problem, but watering at night is rarely a good idea.

I always water in the evening, just so the water will soak into the soil and not get broiled away in the sun. In fact, it's probably not good to have fierce sunlight shining on wet plants. Hot water on leaves is probably more damaging to leaves than hot air.

Dan, you're in Texas... that's a good example of climate difference. Do you overhead water by sprinkler?

For small plants, I overhead water with a sprinkler. For large plants, I sprinkle underneath the plants, keeping most of the foliage above dry. But yes, climate probably makes a big difference. By the same token, our summer nights are very warm, and foliage dries off pretty effectively.

Like rgreen I never water at nite, not even with my drip lines or soaker hose as they still contribute extra humidity to the area. Wouldn't use a sprinkler period. Talk about water waste and ineffective delivery to the plants!

Not only do the nite temps fall into the fungus-loving range here this time of year (as with Dan come late-July here it won't be an issue) but the breeze dies down too that I depend on to dry out foliage. I have seen enough damage on many garden vegetables just from night time rains to not add to the problems created

Have you considered buying a water timer? Isn't there some period of time during the day that it could turn on the hose and water for you without screwing up the household routine?

Invest in a plastic rainbarrel or two to collect water either from the rain or from the well in the middle of the night for the garden. $5 at any recycling center. Just make sure to find out what it had in it before. If all else fails go to the old standby of gallon milk jugs with some small holes in the bottom set by each plant. Some bury them about 1/2 way. You can fill them with the hose and let them slowly water the plants for you.

Dave

Of course I gave no knowledge of your climate hair metal, but my personal take is that if evening suits you it's not that big a deal. It rains at night doesn't it? It certainly does on my garden.

Summer highs average in the upper 80s F (around 32C), nights around 65-68 (upper teens C). Can be hotter or somewhat cooler.

Knowing the temps doesn't really help me because I don't know how plants behave in those conditions. I can only repeat that since it rains at night getting up at the crack of dawn just to avoid wetting foliage in the evening doesn't make a lot of sense to me. A timer would seem to be your answer.

Maryland is hot and humid and plants such as zucchini will get fungus. It has been unseasonably cooler and less humid and lots of rain this season. I try not to water at night, for the purpose of it being cooler and more likely to attract fungi and slugs/snails. But the evening showers do happen and I check the plants the next day for any signs of insects, and slugs. I would do rain barrels as suggested. You could also water at night and see how your plants and bug life respond.

Yeah, in my experience, nighttime rains happen, and unfortunately, so does fungi. As others have said, why add to the opportunities for disease?

I water in the evening in very early spring, but once nighttime temps are in that mildew/mold range, I try to be more careful.

Most of our summer rain is from PM Thunderstorms. Wet overnight is the rule. So if I water once a week, can it be that much worse than nature? We get more storms than that usually anyway. It's the weeks they are lacking that I will water.

I am getting a rain barrel.

"can it be that much worse than nature"

Yes it can simply because of the increased frequency. But the only way you'll find out for sure is to do it and see what happens for yourself. Just be prepared to deal with any fungus issues that develop.

Dave

Hairmetal - I live in MD as well. With our summer humidity and PM thunderstorms (as you have already pointed out) the chance of fungus issues is already high. Even when I do everything right, I still end up battling leaf spot on my tomatoes and powdery mildew on my cukes. I would avoid watering at night if at all possible. If its not possible then I would use soaker hoses, they are cheap and at least it keeps the water off the foliage of the plants.

I'm researching drip irrigation.

Question:

Does the temperature of the irrigation water have any lasting effect on soil temperature? My well water is still coming out of the ground at about 59 degrees F. I don't want to chill my warm weather plants.

Well, thermal physics gives a clue. The heat capacity of water and soil are similar, so if you have 71F soil, and irrigate with 59F water, you'll reduce the soil temperature to 65F IF you throw as much water on the soil as there is soil there. Ain't gonna happen. Also, with a sprinkler system, the drops of water will be pretty much at air temperature by the time they hit the ground. A drip system is so slow, it'll warm up in the pipes before it comes out of the emitter.