I had this idea when I was at the shack and I am putting it into practise today. You see, terracotta is porous and I always seal my terracotta pots before I put plants in them, so I thought they would be a useful receptacle for storing water and letting it seep slowly into the soil, especially for use with rainwater tanks where I want to encourage people not to install a pump. So I bought a long thin one, about the height of my little dog (about 30cm, the pot not the dog) and I bunged up the hole with a 20c piece (just for fun - it's an investment) glued in with silicone.
I put some water in later and I could see it begin to seep out the sides almost immediately. See the darker colour at the bottom.
Then I dug a hole in the ground - that's when I found the worms - and, eventually, put the pot in it and filled the pot with water.
I filled firmly around the pot with good soil mixed with a handful of wet coir block (excellent for holding water) and laid my dripper line over so it will get water once a week when this dripperline comes on. It is a dryer spot here as it is the end point of the dripper system so it will be interesting to test this plan in such a tough spot.
I then planted some lettuce seedlings all around the pot and watered them in well. I would have put the soil up to the lip of the pot or dug the hole deeper but a) I got down to the rock below and couldn't go any deeper and b) I didn't have any more soil available. Then I put some mulch around, all the while trying to think what I could use for a lid...ah yes "The Collage" (see article below). So off I went...
Of course - some of that packaging foam would be ideal. I cut out a piece with a stanley knife, making a groove for the tube to fit through, put a rock on top and there we go.
Another option is to put water plants in the pots eg water spinach (kang kong) or other edible things that would be happy in such a long thin pot (water chestnuts need something wider). I will do this next.
The idea is to use several of these, linked by a tube to the rain water tank or tap. They will happily fill using gravity alone. You wouldn't have a dripper system to worry about - unlike my set-up - and you wouldn't be using electricity to water your garden. I will see how well they work in the next few weeks. Please leave a comment if you have some fine-tuning or questions.