Drip Irrigation

At the Transition Middlesex meeting last night, I mentioned that I'm planning to put in some irrigation this spring. Those of you who know me, know that I hardly water my gardens at all, once the plants are established, and take pride in this. If well mulched, many crops do just fine with no watering.

That said, some crops fail with insufficient water, and others will bear much more fruit if they receive a consistent supply of water right to their roots.

A few years ago I read Robert Kourik's excellent book on Drip Irrigation, which I highly recommend (along with Kourik's other books). After reading his book, I learned that there was a company that sold what he considered the best system for drip irrigation - http://www.naturalgardening.com. His book is very instructive, and tells you how to design your own system, or what to look for in a kit.

Now, a couple of years later, I have a reason to irrigate sooner than later - I've got a bunch of bare-root trees and plants coming in the next few weeks, and have sacrificed one of my annual raised beds for them while they await their permanent homes. Knowing my history with watering, I figured I better protect these plants, and take advantage of the opportunity for a more fruitful garden.

Some of the major advantages of drip irrigation over other forms of irrigation are

• the water goes directly to the roots, where the plants absorb it the best
• because the water seeps in at one small point, and then spreads out under the soil, the plants are encouraged to grow larger deeper root systems, as opposed to spreading out a thin lattice of roots right at the surface. 
• less water is wasted to evaporation, as ideally your drip lines are under mulch, and not directly affected by the air above
• most fruit is effected by the amount of water the plant gets. The effects range from larger fruit to better flavor. 

The particular type I'm looking at from Natural Gardening is a line with drip points every foot, which is good for all soil types, and at each point, they feature a type of dripper called a tortuous path, which is a fancy way of saying the water goes through a labyrinth that controls the pressure, but also prevents soil from getting sucked back up into the hosing (a major problem with other systems).

Does anyone else use drip irrigation? What is your experience with it?

Added on March 27:

Someone asked me by email to elaborate a bit further on why I was considering this particular company, which is based in California, as opposed to a more local option, like Lee Valley. Note that I do have limited experience in this area, but responded to this question thus:

I know, it's unfortunate that Natural Gardening is in California, but I think I'll still use them, and these are some of the reasons:

• Flexible vs. hard (polyethylene vs PVC) - The stuff at Lee Valley that's closest to this system I'm looking at is hardbodied, so much more awkward to work with, and though I don't know this for certain, I'm kind of assuming what they are selling is PVC, which I prefer to avoid as much as possible, because of the dangers of vinyl in general (during manufacture to workers, and also when cutting it, to end-users).
• The type of emitters used are pressure compensating, which means that they will all give out a consistent amount of water - even if at the end of the hose. Many other systems will give out more water at the start of the hose, and by the end, be giving out almost none. Now, unfortunately, this means that these will not work with a gravity-fed water system (ie. rain barrel) without a pump to get pressure up to 25psi. I figure that this particular watering system will be servicing mostly my intensively grown annual crops, so I'll want to have them consistently watered at all points along the hose, even though there is a small amount of electricity used for the pumping. In theory, I'm sure there's a way to provide that pressure with a hand pump, but that's an exploration for another day. 
• My application is pretty big. My original plan was going to be close to 400' of emitter hose. I've since learned that the maximum I can do, and safely keep the emitters pressurized properly, is 326', so I'll have to re-jig my plan slightly. Of course, you can also have more than one set up, and just change the hoses when you need to use one or the other, but I'm only really watering annual vegetables with this, so more than one doesn't make sense for me. My fruit and nut trees will eventually get some attention through a combination of minor earthworks and grey water/rain barrel distribution.

I'm lucky enough to live somewhere with a very abundant aquifer under me. That doesn't mean I intend to abuse that water, but that rain water and grey water systems can be a bit further down my to do list, for the time being.

As I mentioned in the original post, I hardly water at all during the growing season, once things are established, mostly relying on mulch (such as straw/hay, but also wood chips, in some cases) to keep the ground moist. Even last summer, with a pretty long droughty period, I didn't water my tomatoes at all, and got an okay sized crop - a bit less than usual. Of course - I had some crops fail completely due to the drought as well, so I'm hoping this will address that problem.