Try water-wicking

Watering your plants with the water-wicking method can be a great way to conserve water and keep your plants hydrated. By using a water-wicking plant pot, you will be able to collect the moisture from the surrounding soil and use it to water your plants.

This is a more sustainable way of watering your plants, as you are not relying on rain or irrigation to give them water. First, make sure that the plant pot that you are using is well-drained. Place wicks in the soil and the water container and let gravity water the plants gradually.  Great idea if you are going  to be away for a bit of time.