Here is what I do.

Take a pet Bottle, make a small hole in the Cap, and a larger hole in the Bottom, fill with Water,
and press the Head in soil at 45 degree angle, it will start drip action, keeping the soil moist round the clock. It will take a week or more to consume. This can be done in Flower Pots ad in Flower Beds. In flower beds keep a distance of a yard apart.

I had done this when I left for a week for upcountry. My plants were all fresh on my return

Baqar Shah

I think the main problem would be to make the small hole the right size.

Down here, water would get very hot during a sunny day. I wonder if this would damage the plant as they seem to do better if the root system is cooler than the top.

Now that the full Middle East summer is gearing up, I have been filling these bottles - meaning I have been watering my garden - only once a week! As it gets really hot through to the end of august, I'll up that, but I can guarantee that I'll water less, waste less and pay less for water.
I have a bucket in the shower, which every day goes on another part of the upper container garden. For the lower veggie/herb/flower gardens, which all have the buried bottles, I'll be collecting the water that drips from the air conditioners and using that to fill the bottles.
With all of this, I barely open the hose, barely pay for city water, and so far the garden is happy.
I based all of this loosely on "buried clay pot" irrigation. I use one clay unglazed pot and it works just as well as the bottles. The tomatoes are so big now I have to push them aside to get to the bottle and they can barely be seen.
Want pics?
Peace