How to plan drip irrigation - Layout & zones?

[tanveersattar]

Hello All, 

I need help to plan drip irrigation in my backyard. I have planting beds along three sides of the backyard, with a mix of fruit trees, lilly pillies, small veggie beds some flowers/shrubs. Also on the side of the house there is also a planting area with daisies and other smalls flowering shrubs as shown in the image below.

The bed on the south side has three fruit trees and three small round veggie patches and it is 7 meters long.

The bed on the west side has 8 lilly pillies and some flowers (daisies and abela) under-planted. It is 14 meters long. 

The bed on the north side has some citrus plants and an orange jasmine at the end. It is 10 meters long. 

The area, next to the house, on eastern side has some daisies and other small shrubs/grasses. It is 14 meters long. 

A recycled water tap is also on this eastern wall (as shown below). 

I may also need to run two lines to the side areas of the house where we have some photinias in the large pots. If i extend irrigation to the north side and south sides of the house this will add another 10 meter on each side.  

So total length of polytube in the backyard is 45 meters. And if i add two side paths it will be 20 meters more. 

My questions are below:

Q1: If I have to run the main line from tap to cover all these areas around, should I use 19mm or 25 mm polytube?

Q2: As the plants water requirements are different (trees may need water less frequently than the veggies or shrubs/flowers) should I run two separate main lines of 19mm OR 25mm so that I can set frequency separately? OR there should be another way to meet different water requirements? 

Q3: If two main lines are to be used, does that mean two zones and thus water controller with two zones?

Q4: What drippers/emitters should I use? I am thinking of using dripline for all the trees while drippers on the flowers/shrubs. Please suggest what will serve the needs betters. Also will I need any in-line valves to control flow anywhere in this layout?

Q5: Is it recommended to use the pressure reducer on the tap? And also to use back-flow prevention valve to prevent soiled water going back to mains?

Q6: I am planning to use the recycled water for irrigation, I read that it is safe to use for all plants including veggies. Please share if there should be any concerns regarding its use?

I really appreciate help and tips for all experiences gardeners out there. Thanks so much. 

[tanveersattar]

Hi @robchin 

Excellent nuggets of advice there, thanks. 

I went shopping to Bunnings today. I bought 19mm poly pipe (as per my plan above) to run two main lines along the perimeter and I will take out 13mm tubing from it where needed to take to either drip lines (as in vegies or trees) or (as you suggested) drippers along shrubs. I have bought few drippers but will add more as I go. I have also bought 13mm dripline. 

I bought 3-way Holman manifold as well to put on the tap to split from the start. But instead of two timers I chose Holman WX2 (which has two outlets and two zones configuration). So I will use one outlet from manifold to put this timer on and start two 19mm pipes from there. Lets see how it goes. 

One question regarding Photinias in the side path: you are suggesting a separate run because of their low water requirement? I have a patio in the middle and running another pipe from tap may be tricky (as it gets on the concrete path and then over the garden bed along the fence. If I put photinias on zone 2 (on which I have trees) and put less drippers if the water requirement is low, do you think it should work?

Another question which you or @EricL might be able to answer; as per suggestion from Eric I had a look at Rain Bird pressure regulator but it has outlet pressure of 40 PSI and I have been reading that people suggest not to go above 25-30 PSI if you are not using sprayer (which I am not as I am not using system to spray the lawn, I have turf). Also I was unable to find the connectors/adapter to fit in the timer and then to poly pipe. So I bought Holman 19mm Pressure Reducer and Filter Assembly. Its reviews are not very positive but it has outlet pressure of 180kpa (26 PSI) and has filter inbuilt and adapters for my setup (to timer and to 19mm poly pipe). Any comments/feedback/suggestion regarding use of pressure reducer?

Regards

[MitchellMc]

Hi @tanveersattar,

@robchin will hopefully be able to clarify, but it sounds like you could go with your plan but use a variable dripper on the Photinias to regulate their water flow. You'd adjust the dripper flow if they require more or less water than the other shrubs on their line. However, Rob might be implying that the requirement difference might be outside the realm of control with a variable dripper, requiring a separate line entirely. It would still be the one line crossing your patio, just isolated, not an additional one.

A pressure reducer will help with even water distribution through your emitters. Too much pressure, and you'll find different delivery rates at each emitter depending on where they are in the system. Let us know if you have any issues with the Holman 19mm Pressure Reducer and Filter Assembly, and if you do, we'd be happy to facilitate a return of it.

Mitchell

[tanveersattar]

Thanks @MitchellMc

Yes variable flow droppers in photinia pots is a good idea. 

[robchin]

Hi all.

Firstly - gardens are not designed around irrigation systems - you will never have a perfect system. 

I would run the Photinias on a separate line because they will get different environmental conditions eg. Sunlight, shade, rainfall, wind etc than other parts of your garden. Given my comments about and your notes on the time - a compromise is always OK if not ideal. Without getting too complicated it might be a good idea to put in a couple of simple inline shut-off valves AFTER the timer and before the first dripper to allow you to switch either of that line of drippers off if you need to. K-Rain 19mm Barbed Inline Valve - Bunnings Australia Does that make sense? 

In relation to the pressure reducer - don't be stressed about that. 40PSI - which is about 280kpa is fine for drippers. Not perfect but you won't notice the difference in performance. Much better than not having one. 

Good luck.

[tanveersattar]

Thanks @robchin 
I have started laying down the pipes now and on the sides of the house I have put valves as you mentioned to shut off flow if needed. I am starting off with drip line around trees and variable flow drippers on all shrubs/flowers. I will share my learnings here as I go. 

Regards.

[EricL]

Hi @tanveersattar 

Please keep us updated with your progress. We look forward to seeing your drip irrigation system up and running.

Eric

[jaiprak]

@tanveersattar - based on my exp with 4 different irrigation lines including a pop sprinkler here are some hard learning’s:

1. drippers take a long time to drip and provide enough water for the bed. My bed is 50 cm wide and it doesn’t wet the entire are even after 2 hours

2. Tricklers also wet that particular area and don’t water completely.

3. I found sprayer (180 or 360) seems to do a better job in wetting entire area

4. K-rain is cheaper than pope or Holman and comparable in quality

5. 13mm pipe was enough to water about 25m with about 20-30 emitters.

6. Use sprayers for veggies beds, emitters for single plants and trees (they might need two)

[tanveersattar]

Hi @jaiprak 

Thanks for sharing your experience. 
I have put two rings of drip line around my trees for now. I also feel that it takes lot of time to deliver enough water. I will monitor for sometime and may take your advice to switch to couple of emitters for each tree instead, if dripline does not work effectively. 
I have already installed K-rain variable flow emitters for all my flowers/shrubs and they look good to deliver water quickly. As for vegetables I have to install something yet, so let me think about sprayers for that.

I am using 19mm as my main delivery line and then 13mm poly or 13mm dripline for taking off to trees, 4mm from mains for drippers.

I bought K-rain where I can find their product and Holman/Pope if I could not find it from K-rain. I agree they are cheaper and look ok for my use around garden. 

Regards.

[tanveersattar]

Hi @EricL  yes sure, let me take some photos during and after installation and I will share here.

[tanveersattar]

Thanks everyone for all the helpful advice. I have finally installed my drip irrigation after few weekends work. 

First of all, here is the updated plan:

This is the head assembly at the tap with 3-way outlet, timer and then pressure reducer/filter:

Note: WIFI hub installation can be tricky if you have mesh router. 

I have marked poly pipes with Z1 and Z2, after laying them down, for me to remember which pipe I am putting the fitting on (I made a mistake of putting two dripper holes on my zone 2 pipe which I have to plug later). 

I am using 19mm poly pipe as my main lines for zone 1 and 2. This image below shows pipe going to shrubs with 4mm pipe and dripper at the end.

It then runs along the south garden bed, where zone 2 is supplying water to fruit trees with 13mm drip line rings.

In round vegetable patches I made a 13 mm poly pipe ring, attached it to 19mm main line and then put 360 degree variable flow sprayers on that 13 mm pipe.

Two 19 x 15mm Single BSP Female Poly Threaded Tees are placed in corner for flushing water when needed. 

It then continues along western edge in same configuration (zone 2 supplying water to Lilly Pillies with 13mm drip line rings and 4mm drippers from zone 1 supplying water to shrubs. 

In the corner again, two 19x15m BSP tees for flushing.

On northern side of the border, same configuration continues.

At the end of the northern bed, pipes are coming back to connect at the start (making a loop).

But also zone 1 pipe continues along the side fence to water Photinias in the containers. I put valve on that line in case I need to shut it off sometime. 

 A pipe, from zone 1, was brought in from north west corner to supply water to three large pots. At the end I have drippers attached inside the pots.  

  

This is how it looks like finally:

   

I am running it for few days (manual and automated) to test. If all goes well. I will put mulch to cover the pipes. 

Some learnings:

- Buy some extra fittings (elbows, joiners, tees). You don't want to run to Bunnings in the middle of your work. But you can return those packs that you have not opened and used. 

- Measure the pipe correctly, I bought some extra 13 mm and I went short on 4mm. 

- It was good idea to mark pipes with silver sharpie with zone numbering to avoid making wrong holes for fittings in the wrong zone pipe. 

- An old thermos with hot water came in handy to dip poly pipe ends in it, to make it soft and easy to use on barbed fittings (tees, elbows, joiners etc), your elbows will thank you  

- Think twice before cutting and puncturing tubes. 

- Driplines around trees take longer time as @jaiprak mentioned, but I had my pipe cut for rings, so I used it. But two drippers on a tree instead might have been better. I will see if I need to do it later. Good thing is they are on zone 2 (separate zone for trees only so I can run that zone for longer).

- I have 46 variable flow drippers along the length of about 50m on 19mm pipe and so far they are working ok. Variable flow drippers helped me adjusting some of them on slower rate than others (depending on the plant or size of container). 

Here are the links of the items I used. 

=================================================================================
--- Misc.
=================================================================================
Holman poly pipe cutter

Jack 20cm Heavy Duty Irrigation Pins (hold-down pins)

Holman poly pipe punch tool

=================================================================================
---- 19mm Poly Pipe and Fittings
=================================================================================
K Rain poly pipe black 19mm

K Rain 19mm rachet clamps

K Rain 19mm barbed elbow

K Rain 19x13mm reducing joiners

Toro 19mm Tee x 13mm Barbed Reducing Joiner

K-Rain 19mm Barbed Joiners

K-Rain 19mm Barbed Tees

K-Rain 19mm End Plugs

=================================================================================
---- 13mm Poly Pipe and Fittings
=================================================================================

Holman 13mm x 25m Black Poly Pipe

Holman 13mm Techline PC Irrigation Drip Tube

K-Rain 13mm Ratchet Clamps

K-Rain 13mm Barbed Joiners

K-Rain 13mm Barbed Tees

K-Rain 13mm Barbed End Plugs

=================================================================================
---- 4mm Tubing and drippers/emitters
=================================================================================
Pope Repair Plugs

Holman 4mm x 10m Irrigation Drip Flex Tube

Pope 4mm Barbed Off-Take Joiners

Pope 4mm Barbed Tees

K-Rain 360°Adjustable Emitter Trickler

=================================================================================
---- Head Assembly
=================================================================================
Holman 3 way metal tap outlet

Holman WX2 Dual Outlet Tap Timer and Wi-Fi Hub

Holman 13mm Pressure Reducer And Filter Assembly

Toro 19 x 15mm Single BSP Female Poly Threaded Tee

Once again thanks for all the help and let me know your thoughts/feedback. 

~Tanveer