Making the Olla
I have commented on the olla bed in a previous post. The bed has worked well providing us with most of our salad greens over the last year and as I have just replanted it again this time with a different mix including some tomatoes.
With the prospect of a hotter dryer summer this year I will be adding in some more in other beds and thought this might be a good time to go over the process I used to make up the olla and beds.
The olla that form the core of the unit are simply an unglazed earthen ware container to hold water. The water will pass through the pores of the clay by the process of osmoses, being drawn into the soil and the plants roots will take up the moisture from the soil. It allows you to avoid watering every day and wastes a lot less water as the water is applied directly to the roots of the plants avoiding evaporation. I have also noted that while the planted seedlings did well weeds could not get going as there water is kept below the surface this reduced the weeding. The down side of this was that without extra watering vegetable seeds will not germinate effectively so you are best to used seedlings that you have grown in a hot house or warm bed.
I was lucky that I a friend of A.s mother had some old terracotta pipe pieces she was selling for $3 each and I had some old pot saucers I had got with some pots from Bunnings a few years ago.
The first step was to sand back the glaze from the pots inside and out. What these pipes where origonaly meant for which is to keeping water in is not what I am after. I am after a porous effect and sanding back the glaze helps this osmoses effect.
I then used some silicon to attach the bases and filled them with water to make sure that they (A). did not leak and (B) to see if over time the water started to move through the walls of the pipes as intended.
Two of them worked straight away and in an hour water could be seen beading on the outside of the pipes walls.
A quick extra sand and the last one filled and rechecked and all three were up and running.
All up they probably cost me about $5 each. In third world countries they cost around 25 cents each made locally and while this might sound cheap if you do the math’s 25 cents for person on a couple of dollars a day adds up to around $40 each if I purchased them here in Australia.
These olla can also be a great way to use up old terracotta pots joined together when they get old as the qualities that you need which is the breakdown of the glaze on the pots over time is why they are less useful now as pots and make great olla.
Shortly I will post on how I used them in a bathtub garden bed along with an integrated worm farm.