Ruben, I think it would work, but I don't think it is optimal since in my limited experience tomatoes prefer a good root watering and then allowing the soil to get somewhat dry.

Tomatoes are especially vulnerable to Fusarium and Verticillium fungi and I think this style of watering would promote a uniform dampness.

Also, what worries me is that they seem to work based on water tension in what is some sort of calcium mineral block or perhaps a porous ceramic. This means when your plant has peak demand in the day, the probes will need to keep up, and at night when there is no demand, the soil will be as humid as they make it. I think it would work for a plant that is less a water hog than a mature tomato plant. They will also be subject to clogging and impairment with fertilizers and you will probably need several of them for a tomato in a container, which will look like the plant is on a hospital bed with spaghetti tubes scattered about. I can't imagine one of those can deliver more than a half liter in a day - half of which is from 6pm to 6am and unnecessary. You'd probably need about 5 of them for a tomato plant and be dealing with those issues. Great if you need to take off for a few days and don't want to bother the neighbor, I'd think, but not long term...

But the advice is free and I have never used those. I have used an irrometer and it is a wonderful device, 100% US made and with a colorful history. It works on a similar principal but is simply an indicator of soil water âÂÂtensionâÂÂ.

Good luck.