I have successfully tried a method to water a potted plant automatically using a bottle of water.

Method: Fill a bottle with water, invert it and bury in the pot along side the plant as in figure.

Some water will leak into the soil at the mouth of the bottle until no more air is available there to be sucked into the bottle. The moisture at the mouth of the bottle will gradually reach the root system of the plant by capillary action.

After some time the plant absorbs water from the pot soil and cause it to be dry. Some water can evaporate too.Then air can be sucked into the bottle again to release some more water. This process goes on until the bottle becomes empty when it has to be manually filled, inverted and buried again. However the top soil of the pot will remain dry.

The chicken drinker of poultry farms has inspired me.

This method ensures that the amount of water required to keep the root system just wet is supplied automatically.

To prevent water from flowing out through the bottom drain hole, either a pot with the drain hole about two centimeters above the bottom can be taken or the mouth of the bottle can be placed in a cup full of soil buried at the bottom.

In case of outdoor pots the bottle of water will not be consumed during rain.

If required a suitable liquid fertilizer can be added to the water in the bottle.

Your views please.