The Simplest Self Watering Container Garden for Vegetables or Even Trees

No piping required. No electric components or complicated controls.

From just a tray, water bottle and some growth medium in a container and your plants will be content throughout the growing season with minimal input.

You will need:

A tray that can hold its shape and that is large enough for the plant container and the water bottle

A 5L plastic water bottle or other transparent container that can seal completely and hold a substantial amount of water

A drill or sharp utility knife

A container in which the plant will grow. This can be terracotta, plastic or preferably 80% shade netting formed into a grow bag

Grow medium, which can be made up of compost, vermicompost, and if possible vermiculite and peat moss and coir.

The grow medium can be composed of vermicompost only, but to improve aeration and capillary wicking up of the moisture. A third of the mixture can be composed of a mixture of Coir and peat moss. Coir holds water very well, and takes long to break down (it can last up to ten years), however it does not hold chemicals that plants require, this is where the peat moss comes in. The peat also holds water, but it also holds nutrients which can be released to the roots as required. The vermiculite helps to prevent the soil from compacting. You have to figure your soil mix and chemical additives on your own. This step merely acts as a suggestion.

Also look into

super phosphate

bonemeal

compost tea

liquid organic or artificial fertiliser.

I suggest a light concentration of compost tea and liquid organic and artificial fertiliser once to twice a week. Plants got to eat. The nutrients may build up if there is no rain to wash out the system every once in a while, but mostly this won't be a problem if you top up the water bottle with clean water.

In order to ensure that the growth medium is wicking up moisture, drench the growth medium as you add it to the pot/growth bag. This ensures that there exists a water column that extends all the way to the top. If the growth medium ever dries out, then water thoroughly from the top until water is flowing freely out the bottom of the pot/growth bag

The top layer of soil may be too dry for the vegetable seeds to
germinate, because of evaporation of water from the top soil layer. If you however lightly water the plant from the top during the course of the germination period and apply a light mulch cover (which composes of either grass cuttings or crushed leaves or shredded newspaper) then your seeds will germinate beautifully.