Introduction: Reconfigurable Vegetable Garden Watering System

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About: I'm a computer systems engineer living on an acre in the Adelaide hills of South Australia.
When I first started with my vegetable patch I'd spend hours watering by hand. That got old pretty fast, so I started setting up micro sprays and drippers to water the beds or individual plants. However as soon as I replanted or cycled my garden beds none of the sprays and drippers were in the right places. So then I'd spend hours and remaking the watering system for the next season, throwing out sections of pipe and fittings I didn't have the patience to recycle. This also got old, but not quite as fast. In the end I discovered a really fast and easy way to reconfigure my watering system. It's scalable to the number and types of beds I have active.

Instead of running the PVC pipe to each bed, each time, I have instead run a large bore PVC pipe down each side of my entire garden area. Then at the end of each planting bed I have added a T-junction and a short pipe off to a PVC valve. When I set up a bed for watering I grab a length of the mid sized PVC pipe, attach it to the valve, stake it down so it doesn't move too much, attach all the sprinklers or heads that I need and turn on the valve.

When the bed is no longer active I can turn off the valve and disconnect the sprinkler line. The sprinkler lines get stored over some racks, out of the way, until I need it again. The next time I set up a garden bed, before I make a new sprinkler line, I check what I have stored away. Most of the time, these days, it is a simple mater of connecting an existing sprinkler line and the newly planted bed is being irrigated within 5 minutes.

The advantages of this set up are:
  • I am not watering beds that don't have plants in them, or more likely only have weeds in them. This saves me water.
  • It takes minutes to set up water for new plants, so they are less likely to suffer due to lack of time to water.
  • It is easy to get the irrigation system out of the way for the entire garden at the start of a season so that I can hoe or slash without damaging equipment.
  • The reuse of PVC pipe keeps the cost of irrigation equipment to a minimum.

Step 1: Vetetable Garden Layout

My garden beds change layout from season to season. I move plant types around and try never to have the same plant in the same place two years running. I leave beds unused for seasons at a time. I fertilise with manure and bedding from my chickens and ducks. Occasionally I will add an organic fertiliser. I mulch with pea and wheat straw. I don't have fixed beds but instead dig over the entire garden by hand every year, plus the active beds prior to planting. I'm not a big fan of machine cultivation due to the damage it does to the worms. I have lots of worms and they are really big. (According to a show I saw by David Attenbourgh the biggest earth worms in the world live only an hours drive from my property.)

The result is a fairly chaotic layout that changes size, location and orientation from season to season. So having a flexible irrigation system is necessary if I am to make the best use of my land.

In the diagram shown the beds were established in order of numbering. The larger bed has seasonal vegetables in the top section and herbs in the bottom section. The other two beds tend be planted out to large crops like potatoes, corn and pumpkin.

Step 2: Components

To build this irrigation system I have used the following components:
  • Electronic Watering Timer or clock work watering timer.
  • 19mm low pressure PVC irrigation pipe, main fixed lines
  • 12mm low pressure PVC irrigation pipe, reconfigurable sprinkler lines
  • 5mm low pressure PVC irrigation pipe, runners to sprinklers and drippers
  • 19-to-12mm T junctions, for creating the spur lines off the main line.
  • 12mm low pressure PVC ball valves
  • 19mm & 12mm pipe clips, to hold PVC pipe on spur fittings.
  • micro sprays, 360, 180 & 90 degree coverage.
  • micro sprinklers.
  • drippers
  • wire staples and tent pegs, to hold reconfigurable sprinkler lines in place
  • cable ties, to hold the fixed lines onto the boarder fence
The tools required were:
  • Box cutter or hobby knife, or even secateurs if you're not fussy.
  • Pliers.
  • PVC irrigation hole & sprinkler tool.

Step 3: Fixed Plumbing

The fixed PVC pipes are to provide the permanent support of the watering system. They needed to be placed where they would not get in the way but were accessible from the garden beds. The logical place, for my installation, was to run them along the top of the garden fence. (This fence was originally installed to keep chickens and rabbits out of the vegetable patch.) Other places that would make sense would be alongside a foot path or the boundary of the garden.

To install the fixed pipes they were connected to the main water outlet, with a watering timer or clock work timer. The line was laid down beside the fence and then fixed periodically with cable ties. Then the end of the pipes were terminated with stoppers.

The next step was to work along the fixed pipe and periodically cut it for each stub line or outlet.

The stub lines are constructed from a single 19mm to 12mm T-junction, a small section of 12mm pipe and a shutoff valve.  Each of the push-on spur connections was fastened with an appropriate sized clip or a small section of lock wire twisted tight with pliers.

Step 4: Reconfigurable Plumbing

The sprinkler lines have tended to be built in a couple of different configurations depending on the intended crop for the bed.

One configuration holds 3 or 4 sprinklers on standpipes and maybe support pegs. This is good for beds with short numerous crops like carrots, strawberries or even asparagus.

Another common configuration is one or two parallel lines with numerous drippers along the length on short side lines. This configuration is good for taller crops. It is particularly good for crops where watering over the leaves degrades the quality of the crop. I have found this to be very useful for corn.

There are other random configurations that have been made up to fill a need, so match your setup to your garden.

The reconfigurable capability is exercised by connecting the sprinkler line to a stub line on the fixed plumbing. When no longer required the sprinkler line is removed from the stub.

Removal is often accompanied by some heaving and swearing. It is often easier on a hot day when the PVC is a little more malleable. On other occasions I have cut the line leaving a couple of cm of pipe on the valve spur, to be removed later with a hobby knife. This small loss of pipe is a small price to pay for the convenience. This situation could be improved by using standard garden hose clip-on connectors, however the expense of these fittings compared to the effort doesn't make sense in my case.

Step 5: Storage

The sprinkler lines are large, unwieldy and tend to get tangled. When I can I lay them over the top of a rack I have set up for storage of other temporary garden infrastructure likes bird nets, tomato tubes and garden stakes.

Leaving the lines on the ground works until you mow the grass. Then you have to pick all the little bits of PVC out of the lawn. I don't recommend this approach. I've thoroughly tested it and it has never worked well.

Step 6: Results

Working, taking care of kids, attending social functions and otherwise trying to live your life can mean that you quickly become short of time. Anything that can be done in my case to increase my effectiveness or decrease the time it takes to do a manual job is worth implementing.

The results I get when using a timer tap and some micro sprays is far superior to the results I have when I am required to remember to turn on sprinklers and move them around by hand.

I hope that there is something useful in what I've had to say and show you.