David,

Three questions to start with:

1. Is that water repelling tarps on the are between the row mounds or porous landscape fabric?
2. Does the garden slope to the lake or river and the rate of slope?
3. Where is the water coming from and what is the pressure and flow rate available from the hose?

If you are worried about clogging, look at a pvc pipe with holes drilled to what ever spacing you need. Of course this depends on your flow rate, pressure and slope of the ground. If you need help with finding out how to get these parameters let me know I can help. If you have the proper slope, you may have many options to do what you want. It is just a matter of how long you need to irrigate. Aloha

Mahalo!

1) thats polypropylene weed barrier - it is porous.
2) I have an 11% slope
3) the water originates about 200 yards from my property in a 4" pipe, with a potential head of about 5' when it gets to my property, and about a 6 foot head at the top of the garden. I put in a circular, low-pressure 4" pipe system with 3/4" risers all around the property and the garden, so I keep a reasonably equal pressure. The flow, from the end of a 50 foot long, 3/4 inch dia hose on one of the garden taps is 7.2 gallons per minute, or /0.45 L/ Sec. And the pressure is so low i can shut that off with my thumb.

For the length of irrigation time, its fairly easy/probably better to use the sprays early in the season when the plants are small, or I often just water them by hand. There is about a 2 month period - mid-july - mid sept, where the plants are large, use a lot of water, and keeping an even soil moisture level is important to a good crop.

If you are going to have several half inch holes in the pipes, I don't think you'll have enough water flowing at the end of your run (it'll all escape through the first few holes).

My thought was I could leave enough tubing off the t, and then clamp them down a bit, using some sort of cheap plastic clamp. I might only have to do this for the first few feet, after which the pressure should drop enough that it won't make much difference. But thats just theory.

david,

Thanks for the info. Some thoughts. You could use a 1/2" pvc pipe somewhat suspended on the cattle fence at a 1.5% slope. The 1/2" pipe should be drilled with 1/8" holes at first at about 12" spacing. After trial and error to see if water gets to to the end holes, start enlarging the holes. Slightly enlarge the holes that are running less than others. The 1.5% slope gives you additional head or slight pressure as the water moves down the pipe. This will clogs less than using emitters and is more reliable over the long term.
Another thought is to dam up the ends of the furrows so water ponds along the length of the furrows and soaks into the mounds next to it. This is flood irrigation and wastes about 30% of the water but recharges the ground water and is the fastest method of watering without pressure. JMHO Aloha

The 1/2" pvc pipe with variable size holes might work - I can get the right slope by angling it up as it goes down the hill.

The slope is too steep for the flood irrigation idea to work - I do that for the last 5 feet, but thats as far up as the water extends.

David,

I think I would start with drilling 1/16" hole to begin with and enlarge from there to make sure the water makes it to the end holes. Place cups under the holes at the beginning, middle and end and measure the depth after a good length of time. That will give the difference in flow rates along the line and also give you a start on how long to irrigated to get 1" of water on your plants per week. Make sure you have 1.5 feet per hundred feet or more of down slope on the line away from the source of water. GL JMHO Aloha

I thought I'd resurrect this thread from two years ago and report in. This is one of those very rare occasions where everything went well from the word go.

I bought a coil of 3/4" main line, cut that to the correct lengths, let it get flexible in the sun, than took a drill, grabbed a sharp bit that looked like it might be small enough to start with, 5/32, and started drilling a hole every foot. Stuck a 3/4 female hose fitting on each end, figuring I might need to put water in from both ends, or just as a clean out.

And then tested it out on the ground - ok - water coming out all the holes, time to see how it works on the actual beds. Used UV resistant zip ties to hook it on the cattle panels, following the natural slope of the panels.

Started with a bed where where we pulled the garlic just this morning - figuring no plants to trample down. It just works perfectly. There is slightly more water coming out of the downhill holes, but not enough to fuss with.

It takes about an hour to thoroughly soak a bed.

Spent a couple hours setting up all 8 beds, and I'm happily now watering them with the new system.

So I thought I'd let you all know how smart you are :-)!!

{{gwi:333599}}

{{gwi:333600}}