Time of Day You Water

[Tabasco]

I've been going round and round the web on this subject.

To me, early morning seems to be the most logical time of day to water.
Dusk invites mold / mildew, daytime is bad due to evaporation and possible leaf burn.

The exception I lean toward is possibly sometime during the day, if it is extremely hot and dry, using my drip system.
It waters low to the ground and could help avoid stress.

However, is concerning yourself with stress going to make your plants less hardy, of will it allow for maximum yield?

Thoughts?

[imafan26]

I try to water early in the morning. I have a sprinkler system that is set at 4 am when the water pressure is better.
Not everything is on sprinkler. I prefer to hand water in the morning, but sometimes I just can't. Then I water around 4 pm so at least there is a couple of hours left for the plants to dry out. Some of my plants (usually the ones that haven't been potted up yet) need to be watered a couple of times a day in summer.

[grrlgeek]

I've been going round and round the web on this subject.

I would reason that there are so many seemingly conflicting answers, because there are equally as many scenarios. None are completely wrong (except perhaps, overhead sprinkling at night when it's raining and humid) but not all will be right for every situation.

You need to consider moisture holding capacity of your soil, what type of container or in-ground, temperature, humidity, winds, needs of the plant, Containers will dry out quickly. Sandy soil can't retain a lot of moisture. High humidity increases risk of disease. Hot dry winds increase evaporation. Heavy feeders will be stressed if forced to go without water for too long. Some plants, like peppers, do better when a little stressed for water. If you're using drip irrigation, you don't have to worry about wet leaves, and if you mulch (you mulch, don't you?) then the evaporation from the top of the soil will be a lot less and you will always be delivering the water directly to the root zone.

So, in a perfect world, you want to know the point where the soil is no longer holding moisture that the plant can access, and then you want to replenish that moisture, without letting the plant sit in a puddle. Go back to weather, temp, soil type. You may need to walk the garden several times a day poking your fingers down in the soil, before watering and afterwards. Observing any wilting of the plants. A little bit of wilt in the heat of the day is okay. Does the plant recover in the evening, or at least by morning? Is the soil dry by afternoon? Do you have hot winds blowing at 30mph every evening for 3 hours? (I had to sign a disclosure when I bought my house that it does that here!)

Here are 2 very technical articles (mostly about corn, but you can extrapolate) about optimum water content for maximum yield. Me, I just don't want them to wilt and be mad at me.

SOIL, WATER, AND CROP CHARACTERISTICS IMPORTANT TO IRRIGATION SCHEDULING
https://www.bae.ncsu.edu/programs/extens ... 452-1.html

IRRIGATION SCHEDULING TO IMPROVE WATER- AND ENERGY-USE EFFICIENCIES
https://www.bae.ncsu.edu/programs/extens ... 452-4.html

This article is mostly about lawns, but it makes a good point:
"It is also important to reduce your irrigation frequency. As mentioned previously, disease pressure is increased more by routine irrigations that apply more water than is required.
If your irrigation system utilizes subsurface irrigation (subsurface drip irrigation, or buried drip lines) the issue of irrigating at night or early morning is not important because water is delivered directly to the root zone and therefore no water is present above the soil surface on above ground plant tissue."
Landscape Irrigation Management Part 5: Irrigation Time of Day
https://www.clemson.edu/extension/hgic/p ... c1804.html

I'm in the desert. We water with drip and a few select mini sprayers in the morning (primary watering) before sunrise. Just before sunset, they get a little drink as well. We're on that schedule now, because that's when the soil no longer feels moist 2" below the drip emitters. 6 weeks ago, we watered every 3-4 days at 10am because I didn't want to put ice water on plants in 45 degree temps. The only things that we use sprayers for are open areas with newly sown seeds close to the surface and some groundcover areas. Everything else is drip, buried under mulch. The surface barely gets moist, ever. The schedules get adjusted based on what the soil feels like and what the plants say by their appearance. In high summer, mid afternoon, I give small pots an extra splash with the watering can as well. Your mileage may vary.

[Tabasco]

grrigeek,

I am not mulching.
I just have bare topsoil that I side dress about once a week.

[Cola82]

I water every other day a drip line for about a half hour. I'm still tinkering. Trying to get it right.

[imafan26]

I agree with grrlgeek, there are a lot of factors to consider when watering. The plants, the soil, if it is in containers, the type of container, time of year, and what your plants are used to. Frequent short watering encourages shallow roots which will dry out quickly. Deep watering encourages deep roots and usually less watering. Every plant has its' own watering needs. My vanda and some of my other orchids are hung on trees with little or no media and need to be watered daily. My cactus and succulents are off in a corner that is out of reach of any irrigation emitter or head and they only need to be watered every few days. My container plants need to be watered daily and my grass only needs to be watered a couple of times a week for 20 minutes each time. If I have to weed whack more, it gets less.

Not every one has the convenience of being able to choose the best time to water. If they are still working and they hand water, they have to do it when it fits in their schedule. My water pressure is low so I have to set my sprinklers to go off when the water pressure is highest and not when I need the water to take a bath, flush a toilet, or do the laundry. If the plants are watered this way regularly they adapt or die. As I water about an hour before sunrise, they don't stay wet too long.

The shortest answer about when and how much to water has always been "water as needed".

[rainbowgardener]

I agree that I think early AM watering is generally best for plants. They get more use of the water since it comes during their active cycle, less problems with encouraging fungus with water sitting around too long, etc. However, I have work and a life, so sometimes I end up watering when I can...

Watering is also less of an issue for me than some, because I live in wet, humid Cincinnati, where it rains all the time...

[jal_ut]

Perhaps that answer is different for each of us, with different circumstances. Here, the area has a separate pressure irrigation system. I use 4 inch sprinkler pipes with a head every 40 feet. My lot requires 3 runs to get coverage. I let each run operate for 12 hours each week. That puts a little over one inch of water on the area. This is how the system is designed to work and its capacity. The system is part of a reservoir and canal system that covers 1000s of farm acres.
They may run day or night, I don't care one whit.

[chosemerveilleux]

I would like to water only in the morning, but during the week there's just no chance to do so. I have a drip irrigation setup with four manual zones. My two 8x4 foot beds are mulched, one (cuke/melon/zucchini/kale) with straw, while my tomato/eggplant bed has a combination of red perforated tomato and solar mulch on it. Now that we're consistently in the '80's (Zone 6b, Northern NJ) I water these twice a week for 45 min-to an hour. I also have a smaller bed that's approx 6'x2 (imagine a large coffin shaped bed on 4 foot legs made out of trex with wheels) and two 25 gallon smart pots. These require a lot more frequent watering, so I have settled on every other day for 40 minutes, plus daily monitoring of soil moisture and just about daily brief sprays on my lettuce with a sprayer. This seems to have done the trick for me. I am an elementary school teacher, and am teaching summer school right now, so I typically tend to the garden during the week in the early afternoon. on the weekend I'm out there by 9am or so. It seems to work well for me. I have approx 9-10 hours of sun. There are a lot of variables to consider, so I would imagine that these variables (type of growing medium, type and amount of compost used, mulch, etc. etc.) will all need to be taken under consideration. If my beds and containers weren't mulched I would be more worried about watering in the heat of the day, but the veggies seem to be happy, so I'm tickled to death. Good luck!

[JC's Garden]

Perhaps that answer is different for each of us, with different circumstances.

My watering depends on the temperature and humidity. Over the past couple of weeks it's been hot with lower than normal humidity. My plants do better when watered late in the day. I water deep using a hose and water the soil, not the foliage. That way they have water all night and most of the next day without showing stress. If I water in the morning, they start showing stress by evening and production is lost at night. But things can change quickly. For the past couple of weeks I've been cutting okra in the morning. Yesterday we had some cloud cover, didn't lose near as much moisture and I didn't water. Cut okra yesterday morning & afternoon. I harvested slightly more this morning than yesterday afternoon. It wasn't that way last week. I'd hate to have to run a farm this way.

[ElizabethB]

Many opinions and many scenarios.

Right now I have a flat soaker hose in my 4 4'x4' adjacent boxes. They are not close to the house so in the evening I will run the hose to the boxes. I have a timer on the hose bib and set it to go off at 4 a.m. Best water pressure because of low usage (city system). Plants are well hydrated and will not suffer as much stress from the heat of the day. Soaker hoses or drip systems are preferable to sprinklers or other overhead watering. The water is concentrated at the base of the plant - less water needed. Less water lost to evaporation. In south Louisiana there are many problems with mold and fungus as well as soil born viruses so I avoid watering late in the day. If you do use a sprinkler system or overhead water you are better off watering mid day rather than late in the day. The idea that the water droplets will burn the foliage is a misconception. It will evaporate long before the leaves could be damaged. The draw back of watering mid day is that the plants are already stressed from the heat and you lose more water to evaporation.

There is some university based research to support this information - just in a rush and do not have time to look it up.

My 2 cents.

[erins327]

Tabasco,

As you can see you have many answers! It looks like you are further south than me, which means you probably have more of a humidity issue than I do. Right now in the heat of the summer, and hasnt rained nor will it for at least another week, I'm not too worried about having too much moisture.
I watered this morning bc I simply forgot to do it last night. But currently I have tomatoes the size of small trees that are very well established root wise. My soaker hose can easily water down far enough that I don't think night or day is going to affect them. However I just put in some dragon bean seeds, and because they are so immature, I want to keep them relatively wet and cool in this heat, so I do go out every night and water those so they have access to moisture for at least the next 10 hours or so.

[Tabasco]

erins,

Lately here, we have the opposite problem.
If my raised beds weren't so well drained they'd be mini-ponds!

[Wombat]

Heaps of different answers here, but basically it all comes down to your local climate and personal experiences in your own patch. I now water in the morning during summer and the afternoon in winter. When I first started out I was watering every day but this quickly became both impractical and expensive. As I gained knowledge over the seasons I found that improving my soils water retention by adding home made compost and mulching the surface well was the way to go. The organic matter soaks up and releases water slowly, and the advantage is less frequent watering and deeper root systems. Roots grow towards moisture and although surface watering helps out, it forces roots upwards, where the soil is hotter and they're more prone to stress. I now water 2-3 times a week, which means the water penetrates to a depth of between 6-10". By getting the water deep into the ground, this will draw the roots further down into the cooler soil, and develop good healthy plants.

[Tabasco]

As I gained knowledge over the seasons I found that improving my soils water retention by adding home made compost and mulching the surface well was the way to go. The organic matter soaks up and releases water slowly, and the advantage is less frequent watering and deeper root systems. Roots grow towards moisture and although surface watering helps out, it forces roots upwards, where the soil is hotter and they're more prone to stress. I now water 2-3 times a week, which means the water penetrates to a depth of between 6-10". By getting the water deep into the ground, this will draw the roots further down into the cooler soil, and develop good healthy plants.

Great answer!
Pretty much gardening in a nutshell.

[imafan26]

Yes, indeed it is a great answer.

I do add more organic matter and I do pay more attention now, especially with the high cost of water that doesn't go down the drain, and find I can go a day or two on some things. My community garden has been more or less trained to live on once or twice a week deep watering and rain.

However, there are limits to how much organic matter that is practical to add to my soil. I do not use coir at all and I add about 4 inches of compost. If I add too much compost it will hold too much water in the rainy season and everything will die. Compost also shrinks and compacts over time and that added to clay soil can make my soil very hard to work. I tried coir with the orchids, everything in it died because it holds much more water than peat moss.

[Wombat]

I agree with you entirely regarding your wet season water retention. I had a similar problem when I first set up my little patch as I also experience a wet and dry season. It took a bit of experimentation but this is what works for me. First and foremost I had to raise my beds about 12" using railroad sleepers/ties which I bought from my local landscape company, although logs are a good alternative if you have access to a supply of them. This prevents everything being washed away in a deluge. As my yard is mostly clay with a thin topsoil, I then had to re-position them on a slight slope, so that the excess water would have a better chance to drain away. I also have to incorporate a coarse river or builder's sand (not beach sand) into my compost when preparing it. This makes a sandy loam with a mixture of sand, clay and organic matter that's ideal for growing food and this type of soil holds moisture and nutrients very effectively. It also drains well and does not get so affected by water logging. Lastly if I know that heavy rain is on the way I mulch my beds thickly as this helps repel some of the moisture too. You've probably already done this sort of thing but if you haven't, perhaps it may help you a little as I've been there myself.

[Tabasco]

Here are 2 very technical articles (mostly about corn, but you can extrapolate) about optimum water content for maximum yield. Me, I just don't want them to wilt and be mad at me.

SOIL, WATER, AND CROP CHARACTERISTICS IMPORTANT TO IRRIGATION SCHEDULING
https://www.bae.ncsu.edu/programs/extens ... 452-1.html

IRRIGATION SCHEDULING TO IMPROVE WATER- AND ENERGY-USE EFFICIENCIES
https://www.bae.ncsu.edu/programs/extens ... 452-4.html

This article is mostly about lawns, but it makes a good point:
"It is also important to reduce your irrigation frequency. As mentioned previously, disease pressure is increased more by routine irrigations that apply more water than is required.
If your irrigation system utilizes subsurface irrigation (subsurface drip irrigation, or buried drip lines) the issue of irrigating at night or early morning is not important because water is delivered directly to the root zone and therefore no water is present above the soil surface on above ground plant tissue."
Landscape Irrigation Management Part 5: Irrigation Time of Day
https://www.clemson.edu/extension/hgic/p ... c1804.html

Good information that breaks down the mechanics of what's being experienced and discussed in this thread.