Please note, this method has only been used on a flowering garden. If I was growing herbs or vegetables, I would not use this method. If you are growing food, you still may find some benefit in using the sunken pots that are mentioned later.
This method uses recycled roof guttering to act as an irrigation channel in your garden. Your garden will thrive without wasting precious drinking water. All the water is delivered to the root zone which means it is going straight to where it is needed. Water restrictions are becoming more common, so with a little bit of work now, you can still have a healthy garden and feel good about doing your bit for the planet.
I have had this system in place for 4 1/2 years. The soil is a little bit clayey. I was never dedicated to watering and my plants wouldn't thrive and would be lucky to even survive. With this system, the plants get a lot of water with no effort. I thought it would be too much water, but everything is fine so far. No effort has been made to use special shampoos. Just the regular stuff. And the fact that shower water is hot has had no effect.
If your house is on a concrete slab then this instructable is not suitable for you. You may still be able to make your current system of watering more efficient by using the sunken pots.
Step 1: Materials
PVC pipe and fittings compatible with the pipes carrying the waste water from your shower. This is likely to be 50mm-2 inch wide pipe.
Small soft drink bottle. (Optional)
19mm-3/4 inch garden irrigation poly pipe. (Optional)
Length of old roof guttering the same length as your garden and similar length of gutter guard.
Old plant pots approximately 18cm-7 inches wide at the top.
Drill, drill bit about 8mm-5/16 inch.