My thinking would be to put one every foot because you may want to rotate your crops.

I use PVC and put a hole every 6", but that is an overkill, but I use the same tubes for all row crops.

Larry

This is my first year with drip irrigation in the garden. my tomatoes are 4 ft. apart. the 1GPH emitters are 6 inches away from the plant; two emitters per plant. I'm watering 1.5 hours every day; 0400 it starts.

LCDollar, None of us can tell you how many emitters or how closely to space them because we do not know how well your soil holds moisture and only you can learn through trial and error what works for you. Nor do we know how many gallons per hour are moving through your system.

There is great variation between the way water moves through different types of soil. I have mostly clay and it will hold moisture a long time, but at the sandy end of the garden the soil dries out more quickly. However, if I let the clay get too dry, it hardens and the water runs right off instead of being absorbed so I have to work to keep the soil evenly moist. I had to tailor my drip irrigation system to work with the different soils by using valves so I can cut off some parts of the system and only water parts of it at a time.

Be careful not to water too much. I water about once a week for however long it takes for the moisture to work its way down deeply in the soil, and it isn't ever really that long...maybe an hour or so or maybe two hours if it is really hot and really windy.

It is always better to water deeply less often than to water more often but shallowly.

In typical spring weather I will water about once a week if it isn't raining at all or maybe once or twice a month (if needed) if we are getting regular rainfall but not enough rainfall for the plants to be happy.

If you water often but shallowly, your roots stay right up there in the upper few inches of the soil which isn't the best thing in our climate. You want to water deeply so the roots will stretch down deep to use that moisture. Deep-rooted plants show less stress in the heat of the summer than those with shallow roots which dry out more quickly and also get hotter because they are so much closer to the surface of the soil.

You don't want to keep your soil soggy, just evenly moist. Keeping it too wet will lead to all sorts of issues, including disease and plant death. Having the soil fluctuate from very wet to very dry can cause fruit quality issues. Tomatoes don't like very wet and soggy soil. They like moist to even slightly dry soil.

I don't know how experienced you are at growing tomatoes, but if you are relatively new at them, you might not be aware that overwatering often gives you huge plants and large fruit with poor flavor. Genetically, the fruit only have a certain amount of flavor components. If you water a lot, it waters down the flavor and the tomatoes can have poor flavor and poor texture. The best tomatoes in the world in terms of flavor usually are dryland farmed with no irrigation, though that is really hard to do here in July and August about 9 years out of 10. I come as close to dryland farming as I can without actually letting the plants wilt from getting too dry.

Plants will wilt not only if they are too dry, but also if their roots are getting too much water, so watch your irrigation system carefully and never assume that wilting means the plants are too dry. Always stick your finger down into the soil several inches (use a trowel to dig down a few inches if the soil is hard and compacted) to check for moisture when plants wilt. If they are wilting and the soil is moist, they don't need water. They are wilting either because the sunlight that day has been especially intense, the wind has been intense or their soil is too wet and they are suffocating.

Nate, That is a whole lot of watering, so be careful or you'll end up with tasteless water bags instead of tasty tomatoes. Too much water is worse than too little, and watering on a schedule usually leads to too much water and kills the flavor.

Dawn

Thanks for the responses. I'd learned by using the search function that watering requirements were going to vary greatly.

But I've got to install emitters. And I have no previous knowledge or experience, that will tell me how many emitters to install. I was just hoping for some guidance.

I will figure out the amount of water, later. But this installation thing is sort've big and pressing, and I need to find a starting point.

Again, thanks for the replies. I like both the idea of two emitters per plant, and one per foot. So maybe, I toss a coin ;) ..... probably work out either way.

OkieDawn,
Thanks for the advice.

LCDollar,

There is an irrigation forum here at garden web and some of the folks there are real pros. They might be able to give you very specific advice on whatever soil type you have.

When we got drip irrigation I just messed around with it until I got it right for my soil and my typical conditions.

Nate, You're welcome. I know how hard you have been working this year in order to have a better tomato year and I just don't want for you to cause yourself grief by overwatering. That would be a crushing blow....to do all that work and have tasteless tomatoes. I want for you to have incredibly yummy tomatoes to reward your hard work.

Dawn

We use John Deere (there are probably others) drip tubing. They also have filters, regulators and all the various fitting you would neeed. The emitter slits are 8” oc. I have it in several beds and it works great. I use a moisture tester to check before watering, usually every three to five days. I currently have it on tomatoes, corn, onions, cucumber, eggplants and strawberries. Sorry, my good computer is in the shop or I could post a pic.

As of late I use a drip tape that I buy from American Plant Products in OKC, as this is what I use on my tree farm. you can get this tape for about 100-175.00 per 1,000 ft.

I have used Netifim which is a compensating inline emitter designed by Israel. This can be identified as brown in color. Prefer this drip over sticking emitters in 1/2 inch poly pipe.

But the good advice given by OkieDawn is depends on soil type as to how often to water.

BoB