How much daily water required for tomatoes?

[nickel plate]

I've looked up this topic on line and have found only information about "inches of water" which doesn't really apply to my type of irrigation.
I'm using landscape cloth with 4" holes and covered with mulch.
Drip irrigation is on a timer.
Drip heads are the green flag type, occasional pull the flag off to clean out the line (well water) put the flag back in when done.
I ran a one dripper ten minute test which produced 2-1/2 quarts of water which works out to 3-3/4 gallons per hour.
18 Beefsteak varieties and 12 Early Girls. Plants are starting to produce.
Full sun, soil drains O.K.
Central Valley, CA. Last year we got over 20 days of triple digit heat.
Currently I'm watering for 10 minutes a day (2-1/2 quarts per plant) at 7:00 am.
Just right or too much or too little?
Thanks.

[jmsieglaff]

The answer to your question is significantly driven by your weather. It sounds like your summer climate is very hot and dry. The best way to answer your question is to stick your finger in the ground to see how dry it is at the end of the day, if it seems too dry or plants show water stress, increase it. I imagine you'll need to adjust your watering based on your weather at least somewhat--there is no simple recipe IMO.

[D.J. Wolf]

Ok, trying to do some math here to give you an idea of what we figured plants needed per day when I was irrigating small grains and alfalfa. I figure that garden plants are about the same. And with the way the crops shaded the ground, it's almost as if it had mulch as far as water retention went.

When there was no rainfall, highs would be running 80-100. We would adjust and shut off water if we got much rain. our target was 1" every 3 days. That is about what I shoot for on my garden, seemed to work fairly well last year when we were really dry.

I use soaker hose, which averages a watering rate of 1" every 200 minutes roughly. That works out to a flow rate of 1/2 gallon a minute. Now, that is spread out over 50' of hose of course. So 50' of hose would use 100 gallons in the 200 minutes it ran to give you 1" of water. That would be 4 gallons per foot of hose. Your round 4"hole would need roughly half that every 3 days or so to get an inch every 3 days. So for rough figures figure 2 gallons every 3 days. You are running 7.5 qts every 3 days, or pretty close to that figure.

If the plants look healthy and are producing good, I'd keep doing what your doing.

[zendog]

It may be hard to do with the landscape cloth and mulch, but it also helpful to figure out how wide an area you are effectively irrigating with your drip irrigation. If you're watering enough to get it moist right by the stem but the water isn't getting much beyond that you can wind up with a very stunted root system that doesn't spread like a tomato growing in evenly moist soil will. That makes it harder for the plant to take up enough moisture and nutrients in the heat of the day and will lead to stressed plants and lower production.

So if there is any way to lift the edge of the landscape cloth and see how moist the soil is 6", 12" and 18" away from the stem a few inches down in the soil an hour or so after your irrigation runs, that would give you a better picture. Much of this depends on how well the moisture migrates through your soil, but you may find it is better to irrigate with 2 or 3 drip heads around each plant for a more uniform watering, even if that just means running them for a shorter time to give approximately the same amount of water.

[nickel plate]

Crickets-anyone?

[zeuspaul]

I would water less frequently but for a longer time if you are not getting run off. You want to encourage deep roots. My drippers are on for about four hours once a week depending on the weather. I have .5 and 1 gallon per hour drippers so they receive 2 to 4 gallons per watering. If it is hot and dry I water about twice a week or more. Some of my garden is on a slope and I would get run off with faster drippers. If so I would run them for a shorter time several times the same day.

Watch for signs of stress to gauge and modify the total amount of water they get.

[KarenO]

Here’s my “crickets” not sure how many answers you needed?
In my garden it varies day to day. Variety to variety. pot to pot.
Garden bed to garden bed. I need to check them and adjust accordingly.
Daily.
A great many problems can arise from trying to come up with a standard formula or schedule imo
KarenO

[Tormato]

NNNNNNNNNEVER water daily, unless you want bland tomatoes.

[nickel plate]

Originally Posted by Tormato

NNNNNNNNNEVER water daily, unless you want bland tomatoes.

"NNNNNNNNNEVER" Suggestions?
As others have posted, seems like it's a crap shoot water-variety wise but do watch the plants for dry leaf curl, etc. Read somewhere that limiting the normal water cycle every now and then would trick the plants to produce fruit??

[KarenO]

Gary, I said said CHECK them daily.

And in pots, when it’s hot, you may need to water daily. Neeeeever say neeeeeever
There are no absolutes, there are no hard and fast rules to growing anything. This is exactly my point. Each situation is different and needs to be assessed individually. Two pots side by side in the same garden May have different needs. There is no pre- prescribed amount of water tomatoes require because it varies widely.
KarenO

[AKmark]

Originally Posted by KarenO

Gary, I said said CHECK them daily.

And in pots, when it’s hot, you may need to water daily. Neeeeever say neeeeeever
There are no absolutes, there are no hard and fast rules to growing anything. This is exactly my point. Each situation is different and needs to be assessed individually. Two pots side by side in the same garden May have different needs. There is no pre- prescribed amount of water tomatoes require because it varies widely.
KarenO

Agee, it changes daily if you do it right. It also depends if you prune, where you live, what you grow, etc, etc.

Sometimes I water three times a day in a container or they die. We ate a few this morning and they were very good.

[hl2601]

In Colorado I have to water daily. Crazy dry heat here plus altitude plus wind. Sure wish I did not have to!

[nickel plate]

Thanks all.
From what I have read here it's about plant variety, soil, nutrients, sun, heat/cold and moister levels followed by a house favored crap shoot.
Have I left anything out?-probably/possibly so.

[creeker]

I have 30 tomato plants in 5 gallon buckets on rain gutters. They are mostly dwarfs and smaller determinates and now average about 20 to 24 inches tall. They were transplanted around 60 days ago and most are producing small greenies now. The point of this post is to say they are now using about 30 gallons of water a day, one gallon each. This with average daily high temps in mid to upper 80s and morning lows of mid 50s to 60s. I'm sure in just a few weeks with 10 to 15 degree temp increases as well as larger plants they will use a lot more. But their roots are always damp and cool now so they're loving it.

[Oliver]

Originally Posted by nickel plate

Thanks all.
From what I have read here it's about plant variety, soil, nutrients, sun, heat/cold and moister levels followed by a house favored crap shoot.
Have I left anything out?-probably/possibly so.

I think your question has gotten good answers. Something I go by with my garden is to do 2 or possibly three deep waterings per week instead of frequent shallow waterings. That said, it's been in the upper 90's here and some of my plants wilt and the soil gets very dry after 2-3 days. So I water more frequently to keep plants from dying.