How do I judge 1 to 1 1/2 inches of water for my tomato plants?

I've read that my tomato plants need 1 to 1 1/2 inches of water every week. How do I measure this? I live in So Cal so the only water these plants get is the water I put on them. I want to make sure I'm not over watering.

How do I judge 1 to 1 1/2 inches of water for my tomato plants?
It's not necessary to try and measure the water amount. Just give them a good drink once a week and you will be fine. They are not that finicky. They will let you know if you've given them too much by splitting the fruit. If that happens just cut back on the amount of water you give them.
Reply:I asked a gardener that same question about my grass, what he said was put a can down while your watering and when it fills up to the correct amount of inches you have watered enough.





Anyway, I water my tomatoes every night unless it rains for about a half a minute per plant and my tomatoes grow just fine.





It's just a guideline so you don't over water, it will make the roots rot, if in doubt under water you can always water again if it's a really hot day.





You can also try putting mulch down it holds the water in longer, keeps the roots cool and keeps weeds down.
Reply:A tuna can is just right for measuring 1 to 1 1/2 ". But i would water at the base of the plant rather than over the leaves. Adding mulch will help conserve moisture. The tuna can is perfect for the lawn though.
Reply:put an empty coffee can (or similar size container) in your garden, turn the sprinkler on...when there is 11/2 inches of water in the can you are done