Irrigation is a prime area where resourcefulness can save you hundreds or thousands (another one which comes to mind is greenhouses).  I have learned over the years to use the simplest set-ups using whatever parts are available from hardware stores (not nurseries or specialty catalogs).

Of course quality and efficiency cannot be compromised.  I have learned to trust threaded fittings over clamped and compression fittings and will pay extra for all-stainless steel parts such as clamps.  Another aspect of reliability in irrigation is maintenance: I recommend that you do not leave your irrigation hoses behind during the off-season if they can be pulled, cleaned (flushed with clean water) and stored.  I also protect valves from sun degradation by sheltering them with covers and mulch.

On the left is a typical connection from a "sub-main" line to a bed.  A sub-main line is the pipe which brings water to an irrigation zone typically made of several beds.  I have so far 4 zones in my garden, made of about 6 beds, plus a special zone for the greenhouse which only has 2 beds (pictured on the right).  Looking at the details of the left picture, you start with a 3/4" to 1/2" T-fitting with 2 barbed males to connect to the 3/4" sub-main and a 1/2" threaded female for the bed-line.  A 1/2" threaded male fitting follows with 1/2" male barbed, then 1/2" flexible tubing (long enough to reach an adequate spot on the bed), then 1/2" male barbed to 1/2" threaded male, then 1/2 ball valve with 2 threaded female fittings, then 1/2" male threaded to 1/2" barbed to soaker hose.  All threaded fittings are Teflon-taped.  All barbed fittings are clamped on.

I use soaker hoses because they turn and curve easily and because they last if maintained.  They do not puncture easily unless chewed by rodents.  They do cost more than T-tapes and and are best for gardens under one acre. Sizes for lines depend on the total amount of water needed for your garden and the amount of water you start with at the source.  In my case I continue my 3/4" city line with 3/4" for my main and sub-mains.  I start with about 50 psi pressure and find that it can adequately feed up to 500' of soaker hose. I use the bed individual valves to fine-tune each hose to an ideal pressure when your hose stiffens yet still gives in when pinched.

Each zone has a control-valve.  The greenhouse set up as shown on the right is just like any other zone in my garden.  It starts from the main line as seen at bottom and goes out to the zone with a T-fitting.  It meets the zone valve which is a 3/4" 24 Volt controlled-valve.  I chose Rain-Bird valves found at Lowe's for $15.  All valves/zones are controlled by a station which can be programmed for any imaginable irrigation cycle.  Each zone can be programmed independently.  A 6 station control station cost about $35 at Lowe's.

last modified on: Monday November 10, 2008 06:41 AM -0600