It's ambitious to try to give each plant the exact amount of water it needs but not practical or necessary. Even if someone gave you a chart, it would still depend on the quality and friability of your soil as well as the stage of the plant.

So long as you have good drainage, the plants will take what water they need. General rule of thumb is that gardens require one inch of water per week by supplementing rainfall.

You will have to adjust throughout the season and be attentive to the amount of rainfall you receive each week. There are two schools of thought on watering. Frequent shallow waterings or less frequent long, deep waterings. The general rule of thumb is that mature plants need 1-2 inches of rain per week in summer. You should provide whatever portion of this moisture is lacking. One inch of rain equals 65 gallons per 100 square feet of garden space. But this is just a guide. Time of the season, stage of the plants, soil composition, and many other factors affect the amount of water required. Be consistent during fruit production.

Mulched plants require less water than plants that are not mulched. Raised beds require more than non-raised beds.

If a good amount of compost is incorporated into the soil, less water is needed. Compost holds 6 times it's weight in water.

Watering too frequently and too heavily is just as hard on plants as too little water. Roots require oxygen just as much as they require water and nutrients.

Dry winds dehydrate plants.

Cooler temps require less water.

Those using drip irrigation whether from a soaker hose or milk jug are likely getting the best use of their water which is going right where it needs to go and the ground has time to absorb it.

There are hundreds of methods of watering. Whatever you do, just be consistent. But I do agree, twice a day sounds like too much. Roots require oxygen equally as much as they require nutrients and water.

I personally believe in a couple of deep waterings per week with the use of 2 inches of mulch to reduce evaporation and maintain a more stable soil temperature.

Plants recover from dehydration much better then they ever recover from the roots being suffocated by drowning so under watering is better than over watering until you get the hang of it. Oxygen is equally as important as water and nutrients and rain water is always better than municipal tap water.

This may be contoversial because it seems alot of folks have their own 'best' way to water but I will tell you mine. I try and do almost all my watering before 10 am. If you live in a hot dry area that may not be practical but you can conserve alot of water with Mulch.

When you have plants that have different water requirements planted close to, or next to, each other you can vary the amount of water respiration with the type and depth of mulch. A plant that needs alot of water more often ( like a tomato or eggplant )would like a thick layer of fine grass clippings, a plant that does not need as much water or has deeper roots - like Potatoes - would do better with straw mulch that allows more air / gas circulation.

Watering every day does not encourage deep roots. So I try to wait at least 2 days or more between waterings. If you have a rain gauge you can plan your waterings better. I try to get 1.5 - 2" per week. This also varies with soil structure. A good loam with adequate O.M. will always retain water better then a soil with too much %age of sand and will drain better then one with too much clay.

Soaker hoses are good for most plants and reduce loss from evaporation and also let the plants drink slower.

Many people recommend cutting back on watering when fruit is forming to A ) concentrate flavors ( ie Hot Peppers ) and B ) reduce the risk of 'cat face' in tomatoes or rot in potatoes etc ..

Hope I dont get slammed too hard for these are just what I have found to work well for me.

I don't baby anything. If you are using Mel's mix in the beds overwatering is difficult.

Just water when the top inch or two are dry and call it a day.

If your beds are open bottomed over (even bad) soil watering is even less of an issue as the plants that needs lots of water will send roots down into the soil below which pretty much never goes dry.

I have all my veggies on the same automatic watering system except my tomatoes, where I shut it off and mulched heavily. Tomatoes do love water, but if they are allowed to suck up all they want, the fruits will be more watery and blander. So I'm experimenting this year with skimping on the water to see if I can get better fruits. Squashes, on the other hand, are serious drinkers, and I give them what they want because on a hot day they'll wilt if they don't get more than anyone else. I'm mulching them this year so I don't have to be so generous. I gotta say, mulching really, really helps.

That was a very good post Violet and I don't think I could add anything to that.

The timing on this post is perfect for me....

For the last three years watering has been a sore issue; for the last two
years I have planted in non tilled clay/dirt so the water would just sit
there for 10 minutes before soaking in.

This year I tilled the bejesus out of the soil with much better absorbtion results.
however NOW it seems that it does not hold water that well and my mutant zucchinis were starting to dry out.

Over the last 3 days I set up a drip system( 2 gallons per hour) actually what i did was take a plastic cup-cut it in half and put a small hole in the bottom and place a screen over it, then i cut a grove in the cup and place the drip head in the groove and place the cup next to the plant.

So at any given time i can fill the cup with fertilizer and the drip will run through the fertilizer and deliver it right to the roots.

18 plants x 1 gallon a day = big savings on water bill.

My zUKE fruits are growing much faster cuz of the consistant watering.

my thought here is consistancy will win out in the end.

lets hope i did good

gg

my garden is setup with soaker hoses, all underground in each row. they run 2 hours everyday right now due to extreme heat. my peppers are suffering from teh extra water, but my wife planted them in the same row as the toms and i have no way of changing the water schedule for that row without hurting the toms.

the advantage of watering underground is that the roots get the water, and the weed seeds close to the surface don't! plus less mildew problems. at least in my case.

I also have raised beds and do a sort of a square foot method, give or take. I agree with bdobs on most of the watering, with the following exceptions. Melons - once they have fruited you can almost not water them at all. Many consider the secret to good watermelon to be NOT WATERING THEM. I did this last year and got great results - going to do it again this year. Tomatoes - well, mine are in very deep mulched beds with lots of compost and I get away with VERY LITTLE WATERING, like maybe 3 times last season (plus rainfall). Carrots, my friend, or ANY root crops need plenty of water. Lettuce needs a good amount, especially as it gets warmer. And I think you're right about peppers, they don't seem too thirsty.

Great replies people!!!!
I'm using Mels mix in raised beds with plywood bottoms with many many drain holes drilled!
I think at first I was over watering my peppers. I know its hard to over water in a raised bed, but I was watering my peppers every day./...basically keeping the soil moist at all time. The peppers kinda turned yellow and wern't reallly growing. I have resisited the urge to water and now my peppers are a nice deep green with good growth.
I'm in the SF Bay area, and we typically dont get a drop of rain from June through late September.