Drip irrigation?

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grabhorn
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Drip irrigation?

Post by grabhorn »

Over the past four years, I've accumulated and planted 90+ bamboos - both clumpers and runners - spread out across 2 to 3 acres. Summers here in western Washington are very dry, so I have to water weekly if not more often from July through September. Dragging long chains of hoses around and then moving spot sprinklers is a time-consuming hassle. My thought is to set up drip irrigation to cover most of them, especially those that are farthest from the house. It's relatively inexpensive and, while it would require a bit of work to get set up, it would free a lot of time once in place.

My questions are:
  • Will drip irrigation deliver enough water for bamboo?
  • Should loops encircle the plants with multiple emitters?
  • Is it possible to calculate the approximate volume of water needed by a plant of a particular size in a time interval?
  • Anything else I should consider?
Thanks for any experience or guidance you can share.
dependable
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Re: Drip irrigation?

Post by dependable »

Drip irrigation should work fine. Usually I use soaker if the plantings are contiguous, but if they are spaced apart, drip will save a lot of water. For instance, I would normally use soaker for a berm of running bamboo or a hedge, and drip for spaced planting of trees and shrubs.

I do use multiple emitters for larger or more thirsty plants in a mixed planting, circling around is not a bad idea as long as you don't kink the hose. I use ground staples to tack the hose to ground so it stays put and is not a trip hazard. I don't normally calculate much, but do sometimes return to a job to check if there is wilt stress and add more emitters if there is. Emitters come have different rates, usually 2, 4 or 8 liters per hour.

Covering hose between plants with dirt of woodchips will increase hose life, as it does photo degrade. Soaker hose has more of a problem with this than drip line, but drip will break down too eventually.

Soaker hose will also wet a larger area in less time, and you can put runs of regular hose if there are gaps between plantings.

If you want to encourage spread of runners, also water area adjacent to where the plant is to encourage root growth in that direction. For bamboo, you don't need as much depth of wetting as you would use for a tree that you want to send roots down, but longer watering intervals with gaps in watering still encourage root growth better than short cycle watering.

If you are covering a large area and have limited water pressure, run multiple lines instead of one big one to assure pressure near the end. There is a specified pressure for the emitters, you can buy a cheep hose pressure tester at plumbing or irrigation supply to check, but I usually just do a visual at the end of the line.

An in line filter and anti siphon device (if there is not one on your house spigot) is not a bad idea. Rainbird makes a combo filter, anti siphon, pressure regulator unit for about $25. The pressure regulator is useful if you are running short lines with good water pressure, as it reduces emitter pop out, it is not as needed on long runs. Rainbird & Toro work about the same I guess, have used both. It pays to buy a punch tool for installing emitters, if the holes are not just the right size, a lot of emitters will pop out. Some often do anyway.
grabhorn
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Re: Drip irrigation?

Post by grabhorn »

Thanks, dependable. This is great stuff. Very encouraging.

Soaker hoses were my first thought, but the plants are not contiguous, so there would need to be many alternating sections of soaker and regular hose. That would get pretty costly and be a ton of work both to build and to set up and remove every year. And store, and label... Not to mention that there's got to be a lot more evaporative loss with soaker hose. I've seen their super-fine sprays up into the air. So that's how I arrived at drip as a better option.

I must be missing something, because I don't see how emitters can be rated for volume/time without knowing the pressure and how many emitters are on the line. I suppose I should just go for it, measure how much water is delivered, and set up the timer(s) accordingly.

I definitely plan to cover the hose as best I can, especially in sunny areas. And in the few areas where they'll cross a path, I'll bury them a bit. I'm on my own well, so pressure is not high. I have three bibbs around the house (all anti-siphon), and I expect they'll all be drafted into service given the distribution of the bamboos. Some are likely to have multiple lines, too.

I'd definitely buy the punch tool. When I look at the options, there seem to be an incredible number of emitter types. Do you know of any advantages/disadvantages to any of them?

Thanks again for this. Much appreciated.
dependable
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Re: Drip irrigation?

Post by dependable »

With either soaker or drip, I would not take them in every year. It is extra work to no purpose, use the extra effort to bury it some instead, even if just with leaf litter. Soakers do not need to be blown out for winter and the drip line can be blown out with an air caddy with the right fittings, if you do not have a compressor. Actually, I don't always blow out the drip lines either, and they are usually OK, you can just un do some couplers or cut & repair if there is a burst or known low spot.

If you do want soakers, AM Lenard Co sells it in 250 bulk rolls, they also sell fittings and bulk ground staples. Soakers defiantly use more water, if on a well I would probably go with drip.

The emitters measure output, more or less, regardless of pressure or number of emitters as long as there is a minimum specified pressure in the line.

If you are going to make your own lines, as opposed to buying line with pre installed emitters, I have had pretty good luck with the Toro ones. We bought a lot of them to set up a market veg garden my wife was leasing at one point, but that fell though after a few years so I started using up the stock in the landscape business, and usually stick to that line if I remember to order it. Rain bird is more often in the hardware stores though. Don't bother with 'micro emitters' they are mostly for window boxes and the like.

You can also buy line with emitters every foot or so, and you can alternate between that and solid line between plantings. There are strait couplers, T's and 90 degree fittings available in the Toro commercial line. That 'blue stripe' hose is 5/8" if I recall, but the emitters and the couplers also work with the rainbird lines, which are 1/2". Some of the line with pre installed emitters is brown, and blends more.

You can use regular Y hose connectors in series (with on & off feature) to help distribute pressure for multiple lines on the same bib, or you can buy a manifold system, but is more expensive to the same purpose I think.

Let me know if you have any other questions.
grabhorn
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Re: Drip irrigation?

Post by grabhorn »

This is fantastic. Thank you.

I've bought many things from AM Leonard over the years, and I've generally been very happy with them, so definitely look at what they've got. I did look into regular garden hose and soaker hose years ago, and I decided it was the couplings that would have killed me, both in time and money. Drip looks like a much lower cost and effort.

I suppose I should mention that I'm looking at 10-12 runs of ~300 feet each.

I will definitely ask more questions after I do some research to see what options are out there. It's great to have the benefit of your experience.
dependable
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Re: Drip irrigation?

Post by dependable »

With that many runs, I'd be tempted to go with pre installed emitter hose, a lot less work. A M Leonard does carry the Toro blue stripe, with both with & without emitters, also the couplers and other accessories..

You can also add additional emitters to the pre installed line later on if need be.
grabhorn
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Re: Drip irrigation?

Post by grabhorn »

I'd definitely not want to go with pre-installed emitters, because many of them would be in places where I don't need to water. I know it's more work up front, but I'm willing to do it, because I think it will pay off over the long run.

I see many diameters of tubing, 4mm, 1/4-inch, 1/2-inch, 5/8-inch. I'd prefer to go smaller (cheaper and less obtrusive), but not at the risk of becoming ineffective. I assume 4mm is too small. Is 1/4-inch too small? It looks like I can buy most of them in 500-foot rolls, and I'll need a few of those.

Then... Is it better to make an actual loop that surrounds a plant, or is a T with a "spur" that loops around the plant just as good? It seems to me that the "spur" would be easier to modify to adapt to a widening plant.
dependable
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Re: Drip irrigation?

Post by dependable »

The 4mm & 1/4" ones are micro, stay with 1/2 inch at least for what you are doing. 5/8 would be better for long runs. The micro will not convey the volume of water you will need and will will clog with a dead insect, slug, cocoon or whatever.

Alternate between solid hose and hose with emitters, depending if you want water discharge.

Example Given: Run solid 1/2" or 5/8 to planting, couple to hose of same make & diameter that has emitters once you hit the planting bed. Go back to solid if you are going to another bed on same run, then use another in line coupler to go back to emitter hose when you reach second bed, and so on.

Try to keep it as simple as possible, remember, you are doing this on the cheep compared with cost of real irrigation system, but it will still take some time and money if you want it to work.
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