With a master's in sustainable development, Susette helps Southern California water agencies carry out their water conservation projects.
Current research shows that homeowners can save 50-70% of their water bill by optimizing their sprinkler system and using native plants in landscaping. Using the types of sprinkler heads that match the plants you have, so they get the right amount of water and can absorb it properly, is part of optimizing the sprinkler system.
Too much water and you waste what you paid for. Too little water and your plants die. This includes trees. This article will show you the best kinds of sprinkler heads to use for the types of plants you have.
Lack of Water Kills Pine Tree
In the middle of my lawn in the condo complex where I used to live stood a tall, attractive, relatively young pine tree. I noticed it shed needles quite a lot, which sometimes indicates a lack of water. Although the lawn under it was quite green, I was worried and mentioned it to our head office. Clearly, trees need more water than do lawns. They brushed it off.
One night we had a windstorm. I heard a big crack and the next morning saw one of the pine tree's branches lying on my roof. I alerted the front office and suggested they take a matching branch off to keep the tree's weight balanced. I also suggested (again) a change in watering. They ignored both suggestions.
Several months later we had another windstorm. This time the other lower branch cracked off, tearing the trunk in half as it fell. The front office hired a logger to take down the pine tree, who noticed that the tree had no sap. Now pine trees are known for sticky sap that clogs up any chainsaw that prunes them. But this tree wasn't being watered properly, although the grass under it was, and its wood was bone dry.
This could be happening to you—to any of the trees, bushes, flowers, or even the lawn in your landscape. You could be watering too much and drowning your plants, or watering too little and drying them out. Attaching the right kinds of sprinkler heads to your irrigation system, then programming them properly on the controller, is one way to make sure the right amount of water reaches your plants.
Utilizing the Water You Pay For
Sprinkler heads are one of three components of a healthy sprinkler system. There are also the types of plants you've included in your landscape, and the type of controller you use and how it's programmed.
Component 1: Native Plants
Component 2: Irrigation Controller
Component 3: Sprinkler Heads and Nozzles
The sprinkler heads that are right for your landscape will be those that feed water to your plants in the particular way they like it. Some plants, for example, don't like their leaves wet, so you would not want to use a spray head to water that plant. Instead, you would section off that part of the landscape, install whichever of the sprinkler heads below fit that section, and give it its own watering schedule on the controller.
There are three main classes of sprinkler heads: Spray heads and spray rotors with different size and shape nozzles, bubbler heads, and drip or soaker systems. Each works best for a different type of planting.
For lawns, spray works best because of the even application. For trees and shrubs, bubblers work best because of the pooling effect. For flower beds and many crops (like grapes), drip and soaker hoses work best because of slow application to the plant base. Each type is explained below in more detail.
Spray Heads and Rotors for Lawns
What characterizes spray heads (and rotors) is that they spray water up and outward in an even application. This applies water to the surface of plants, including leaves. Since many types of plants do not like their leaves watered, you would use this type of sprinkler mostly on grass.
Most irrigation systems are equipped with nozzles that rest in the ground and only pop up when activated by the controller. They are used in locations where a lawnmower is likely to damage anything standing higher than the grass level.
Sometimes you'll see spray heads set on permanent risers that lift them higher than normal, so they can spray over a garden area with ground cover. Sometimes they're used for flower beds too, where maintenance is hard to come by.
Spray nozzles come in different sizes and spray patterns. Some spray steadily in a 360-degree circle. You would use those in the middle of a lawn. Those that spray in a 180-degree arc (out of only one side) are for the edges of lawns. And those that spray in only a quarter of a circle (90-degree arc) or less are for corners.
For the smaller types, you will periodically need to make sure they are spraying in the right direction, so you don't waste water spraying a sidewalk or driveway (called "arc misalignment"). You can easily adjust them by hand.
Many of California's soils have heavy clay content, which makes them absorb water slowly. The standard spray head gives out too much water for these types of soils. It pumps water constantly, not giving it time to soak in, so water very quickly starts to run off the top of the soil into the storm drains. That is wasted water.
It also pumps water up into the air, which allows for easy evaporation by the sun and for any wind to carry it off. That also is wasted water. The newest nozzles make allowances for both of these situations.
The newest types of spray nozzles on the market today, that water suppliers are paying the most attention to (and giving rebates for), are the rotary stream (or multi-stream) nozzle and the precision nozzle.
The spray of a rotary stream nozzle looks like fingers of water spraying out, rotating slowly from side to side to cover an area, giving time for the water to soak down into the soil.
The precision nozzle is built so the water slows down and becomes slightly heavier before spraying out. This cuts down on evaporation and wind-blow, saving the 30% of water that would otherwise be lost. You would use the rotating nozzle for heavy soils and the precision nozzle where wind and/or sun are strong.
Rotors are sprayers with a very narrow outlet that emit water under high pressure, sending it in jets out 18-55 feet, depending on the size. Rotors rotate back and forth to give soil plenty of time to absorb the water before its rotation brings the jet back.
Most rotors are driven by gears and come in kits with several sizes of nozzles. They need a higher water pressure than spray heads to operate properly. Whereas spray heads need 20-30 psi (pressure per square inch), rotors vary depending on how far you want them to shoot. If you are watering a 30-foot length, you'll need at least 30 psi coming through the pipes. If a 55-foot length, you'll need at least 55 psi.
Bubbler Nozzles for Bushes and Trees
Bubblers are nozzles that bubble over in place, rather than spraying outward to cover a wide area. You place bubbler nozzles near trees and bushes to flood the ground around them. If my pine tree had been watered with a bubbler head, on a separate station with the other trees on the property, it would have been healthy and strong.
Bubblers emit water at a slower speed than do sprayers and can be left to run longer. The intention is to create a pooling of water that sinks down deep into the soil around the tree. Then you leave a long time of not watering, so roots have to search for water, growing deeper as the soil dries on top. Bubbler systems are not regulated by water suppliers, hence you can run them for as long as a tree needs it.
Drip Nozzles and Soaker Hoses for Gardens
Drip and soaker systems are characterized by long hoses that stretch the length of a flower bed or crop row, or that wind around inside of the bed. These systems "leak" water, compared to spray heads. They require a long time of watering to produce the amount desired, but also make it easy for the water to absorb into the soil.
Because there is no runoff and no problem with evaporation or wind-blow, you can save a tremendous amount of water with a drip or soaker system. They are a little more vulnerable to blockage than spray heads, but careful maintenance will make it worthwhile using them.
In addition, plants are healthier because of the lack of water on their leaves. If it doesn't rain in your area, you can still water leaves on occasion to remove dust and insect debris, but be careful. Water left on leaves in the hot sun can cause them to "boil," and water left on leaves for a long time (especially on a cold night) can cause the leaves to rot.
Drip systems have mini-hoses extending from the main hose that are capped by an emitter. Each mini-hose is directed toward the base of a plant, where they dribble water until the ground around it is soaked. If your irrigation system is already set up to use spray heads, you can replace each spray head with a drip nozzle that looks like octopus arms. Each arm can be pointed in a different direction.
A soaker hose is made of canvas to allow water to leak through the surface, or of plastic with tiny holes spaced regularly down its length. Using a soaker hose down a row of crops allows you to water the roots without watering the surrounding soil, which also helps to minimize the growth of weeds.
Notes & Cautions:
- If you're going to have a mix of sprinkler heads watering your landscape, you'll need to give each kind its own schedule. That's what an irrigation controller's "stations" are for - you assign which sprinkler heads go to which station and then program the station with the watering schedule you want.
- Also note that when you landscape with plants native to your area they won't need much, if any, water at all. Some water suppliers offer contests or rebates for changing lawns to native plants.
- Whatever system or combination of systems you end up using, if watering is appropriate to the plant type and the local weather patterns, you will end up with healthy plants and (usually) substantially reduced water bills.
- Of course, it's important to check for leaks regularly and get them fixed as well.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
Questions & Answers
Question: How do I lay out a watering system with irregular planting schemes, with some new trees?
Answer: Use bubblers for the new trees and put them on their own station, so they can be programmed differently from the rest.
Louise89 on September 04, 2019:
Great information, thank you!
Mike Lintro from Provo, Utah on September 20, 2014:
I would never recommend multi-stream rotors to anyone. I have done sprinkler repair for years and i see more problems with those than i do with any other type. They just stop spinning because they get clogged up with hard water, rocks, dirt, really anything. For a garden drip tend to work great, although they can be a bit more expensive than a few gear-driven rotors.
Susette Horspool (author) from Pasadena CA on May 07, 2012:
Definitely check out the rebates mjldgulley354. While you're at it, you might find a retrofit you hadn't thought of. Good luck.
Economicliving-You are right about how much of a mess an irrigation system can be, if you don't know how to take care of it. I once lived in a HOA where their water bills were sky high, due to irrigation problems. One morning I woke up to find 4 geysers going at once!
mljdgulley354 on January 28, 2012:
Shoot! I wish I had known about the rebate thing when we put in our sprinkler system. I think I will go ahead and check it out. Very good hub with lots of great information. Thank you for sharing it.