Friday, May 17, 2013

Drip irrigation with PVC pipe.

I got irrigation tubing in all but one of my raised beds.  For the last bed I thought I'd try something different, PVC pipe.  Why?  I don't know really.  I just wanted to see how it would work compared to the tubing.

This bed is the oddball.  It's 4x4' while the rest of the beds are 4x8'.  The kids took ownership of it and decided what to plant where.  My wife used twine to mark a grid so they could use the square foot gardening method.  

I laid out the PVC pipe along the grid lines.  I didn't bother to glue the joints.  I'm using rain barrels for water and the pressure is low enough that slip fittings work fine without glue.  I used 1/2" PVC pipe and elbows.  Right away I could see one benefit.  The stuff doesn't twist all around while you're trying to get it in place like the tubing does.  Also, since it runs from one side of the bed to the other it's level and suspended above the soil. 

I put a tee in the line of the last bed and ran tubing to a barbed adapter attached to the PVC pipe. 

Then I drilled holes every foot so the emitters would drip and water the squares on either side.  This was the most difficult part.  The emitters are barbed.  I tried to use the same drill bit that I used on the tubing.  The emitters would not go in.  The pipe just didn't have any give to it.  I ended up drilling the holes slightly larger.  The emitters were still very difficult to insert, and once I turned on the water they leaked like crazy around the hole.  That was no good.

The solution?  I got out the silicone and put a good dab on around the base of each emitter and waited over night.  That solved the issue.  After I was finished though I realized that I probably could have just skipped the emitters and just drilled tiny 1/16" holes instead.  I don't know if that would have worked or not, but it would have been a lot easier. 

So what's the verdict?  That's hard to say.  I think the PVC works really well.  I expect it to hold up longer.  All of the emitters seem to drip at a pretty constant rate (I think this is due to everything being level).  But, getting the emitters in those holes was not fun.  The PVC is also more expensive.  Who knows, it might be worth it.  I'll have to see how this works out during the summer.

I got some video of the PVC drip irrigation in action.  
It might be better viewed on youtube in a higher resolution.


  1. I'm so glad you posted this! I'm going to try to do this too. I have some raised beds that I need irrigation for and this seems too simple to not at least attempt. :)

  2. PBC drip irrigation... there's no need for emitters and it needs to be level to work right. The up side is, it'll last forever and in the long run will be cheaper than replacing emitters and tubing when rearranging or when the emitters break from becoming brittle (or clog if you use that type). A 10' 3/4" pvc pipe is less than $3 and when you want to change it up, you can swap out tubes with different spacing since there are no barbs or glue.