Sprinklers and California native plants

Do you really need a sprinkler system?

We stopped installing systems back in the early 1980's because everyone kept overwatering. A customer with the hose seemed to be safer than a sprinkler system that could be turned on easily.

The best watering seems to be an owner with a a hose and a cup of. You can water as much as you wish as long as there's something in your cup, or can, and you do not set the hose down. Some owners like coffee, tea, beer or wine, the plants prefer a wash down with water. In other words a 15 minute wash down once a week sees to help the owner and the plants.

But for larger areas or owners that are seldom there we use very low volume sprinklers. We do not recommend drip for most native plants. It is fine for natives that grow in ponds. Your can read more about drip irrigation on the Drip Page

Drip tubing after a bear ate it. Gophers, squirrels and rabbits also eat it. We do not recommend drip irrigation. Native plants would prefer the holes to drip. - grid24_12

The Basics of a sprinkler system.

Installing Valves

Ok, I'm not going to get into real details. Every property is different and may need a different approach.

But here are some of the basics to figure out as you lay out the system.

You'll need an antisiphon valve as close the the water main as possible. If you need more than one valve, put a stainless steel ball valve between your valves and the main. I like using brass or galvanized according to the metal you are connecting to. After that ball valve you can use plastic. With the ball valve you can shut down the valve(s) when they are stuck open.

Choosing Sprinkers: These are some of the common sprinklers.

The lower volume(precipitation rate) sprinklers allow the water to penetrate the soil better, and we prefer them for washing off the dust. BUT, you'll need to have a timer that waters in the early morning with no wind. I'll not get into timers here, they are pretty straight forward.

Here is a shrub version of a Mp-rotator sprinkler. They will also go onto pop-up bases. - grid24_12

Here is a plastic Rainbird(tm) type impact sprinkler. - grid24_12

There are some fancy sprinklers that do smaller flower beds and corners. Draw out your yard, measure each 'box' and find sprinklers that fit the patterns of the yard. Try to have little over spray, the spray that hits the car, sidewalks, walls. Make sure that the spray from one sprinkler reaches the next sprinkler or you'll have dry spots.

Ok, now count your sprinkler heads in the 'plan'. How many gallons per minute do you need?

Add up the heads and you'll have your gallons per minute.

Approximate gallons per head(I prefer the microsprinklers or the mp series sprinklers)

Rainbird 1800 or A17-F full circle 2.4 gallons/m quarter circle .6 gallon/minute 15 feet radius

Toro 570 full circle, 3.7 gallons/minute; half circle, 1.8 gallons/minute; quarter circle, 1 gallon/minute 15 feet radius

Rainbird MaxiBird 2.4 gallons/min (doesn't matter if it's a qurter of full circle) 36 foot radius

Mp-1000 full circle .8 gallons/minute; quarter circle .2 gallon/minute 14 feet radius

Mp-2000 full cycle 1.7 gallons/min; quarter circle .45 gallon/minute 20 feet radius

MP-3000 full cycle 4 gallons/min ;quarter circle 1 gallon/minute 30 feet radius

Microsprinklers are about .5 gallons/min 6-8 foot radius quarter circle .5 gallon/minute

Connecting your valves and sprinklers

Ok, say you have 6 mp-2000's in half circle, and 4 in quarter circle. So, 6X.9+4X.45= 7.2 gallons/min.

On the next chart you can see that one valve and ¾ pipe should be able to run 8-10 gallons per minute. If your 'plan' calls for 24 gallons a minute you'll need three valves. If you have a shady area and sunny areas try to break the valves up so the shade plants are on one valve. Likewise if some plants 9a lawn) need more water give them a different valve than your cactus garden.

Basic pipes

Pipe size(sch 40 pvc or polyeth)	My recommended maximum*	Possible with no problems
1/2	5 gal/min	5 gal/min
3/4	8 gal/min	10 gal/min
1	12 gal/min	16 gal/min
1 1/4	22 gal/min	28 gal/min
1 1/2	30 gallon/min	40 gallon/min
2	50 gallon/min	60 gallon/min
2 1/2	75 gallon/min	80 gallon/min

*If you use the lower number you generally do not need to count the fittings.

A ¾ inch antisiphon valve can deliver about 15 gallons/minute. If your pressure is low(you can stop the hose with your thumb) you may only be able to get 6-8 gallons/minute out of the valve.

You can use poly, sch 40 or class 200 for your pipes. I prefer sch 40 pvc. Use fresh glue, primer is not needed(may make the joints weaker). Bury your pipes at least a foot deep or you'll be repairing them later. Bury them at three foot and you'll hate yourself before you finish. If your stomach isn't flat before the job, with three foot ditches, it will be flat.

All that really matters in a sprinkler system is that you are covering the ground(or plant foliage) evenly and you do not try to get more out of the pipe than it can deliver. If there is a question of what the pipe you are plumbing into can deliver, turn off the water, put your ball valve on, turn water back on. Turn on ball valve with bucket under it, time it. That's not perfect, but it will give an idea of what is in the pipe.

If you can't figure out how to put the ball valve in, call a professional. Before or after.