I finally figured out how to automatically water with the rain water that I have collected!
Once you harvest rain water, the trick is easily watering your garden.
Regular dripline won't work: the holes are too big and need more pressure than a rainbarrel can supply. I made my own dripline which works with low pressure, and low volume. It is very reliable.
I used 1/2 inch polytubing. You can buy 20 feet or 50 feet or 100 feet at a time. It is available at Lowes or home depot. It is much cheaper online. The trick is to punch VERY tiny holes in the tubing. **More on this later**.
Then, I bought some programmable battery-operated timer valves (ie Hose Water Timer). These vary in how many zones they can water. More zones are better because if you try to water your entire garden with one zone, you will not have enough pressure to reach all the plants. Also, if you have different height-levels in your garden, you'll need a zone for each level. All the height-levels need to be lower than the bottom of your rain barrel.
The poly tubing goes from the rainbarrel (instructions in link at the right) :
The tubing from the rainbarrel (blue) connects to the battery-operated hose timer. The timer gives water to the green poly tubing that goes to the garden (the red shows regular drip-line which didn't work - I'm going to replace it with poly tubing) :
Next, I used 1/2" Barbed Tee connectors to space the tubing evenly throughout my garden. They are cheaper online but you can get them where the tubing is sold :
The green Dot is next to a barbed Tee.
I folded the ends of the tubing with thick wire and turned on the water:
(You could use an end-cap connector for this.)
Next, I started at the end of the supply line (so the air leaves the entire line first) and punched holes where the plants were.
How did I punch the VERY small holes?!! I heated a thin stick pin over a candle and pushed it easily though the pipe. I was very careful to make sure not to catch anything on fire, watching out for wind and leaves etc. I used pliers to hold the pin:
I put the holes on the bottom of the pipe! If you don't do this, the water will squirt very far away when the rain barrel is full (so far that the plant will not get soaked) :
Each time you melt a hole, the pin will need reheating.
I started by putting about 3 holes per plant/area. If a hole clogs, then the plant will still get watered. But too many holes will reduce the pressure so that the holes at the end of the line will not give out any water. This is why I started with 3 holes per plant. I added more when the barrel was almost empty. When it is almost empty, you can judge if the holes are still distributing the water evenly. If they still do, put a few more holes to allow for more-even watering. Picture of a little stream of water:
If the hole were pointing upwards, the water would not squirt on the plant.