Quick answer
Drip irrigation is a watering method that sends water through tubing to small emitters, which release it slowly onto the soil at the base of plants instead of spraying it through the air.
EPA describes the idea as microirrigation: water applied slowly and directly to the roots where it is needed most. A working system needs a filter, pressure control and emitters matched to the plants.
Quick facts
The key facts about Drip Irrigation, with sources:
- What it is
- Tubing and emitters that apply water slowly and directly at plant roots 1
- Filter
- A drip system needs a 150-mesh filter; some emitters and microsprayers need 200 mesh 3
- Pressure
- Clemson prints 20 to 30 psi in one sheet and 30 psi in another; over 40 psi can pop emitters out of the tubing 23
- Emitter flow
- Standard sizes are 1/2, 1 and 2 gallons per hour 2
- Placement
- Emitters sit above ground and under mulch, because buried emitters can plug 2
- Efficiency
- Clemson says drip systems are typically 90 to 95 percent efficient 2
Key takeaways
- Drip waters plants, not air. Water comes out slowly at the roots, which cuts the waste that spray can cause.
- A drip system is only as good as its filter and pressure control. Emitter openings are small and clog easily 3.
- Emitters go above ground, under mulch. Buried emitters can plug with dirt or roots 2.
- Drip fits beds, shrubs, trees and groundcovers. Clemson’s drip sheet covers those uses and does not address lawns 2.
- There is no one schedule. Run time depends on emitter flow, plants, soil and weather, and local watering rules still apply.
Watering one plant at a time, not one lawn at a time
A sprinkler throws water across an area. A drip system puts water where a plant needs it and nowhere else. EPA’s watering tips describe microirrigation as applying water slowly and directly to the roots, where the water is needed most 1.
The water starts at a spigot or a valve, passes through a filter and a pressure regulator, and runs along tubing. Small emitters on the tubing release it a drop at a time.
The Clemson Extension fact sheet on drip says emitters regulate flow, so each one delivers roughly the same amount of water wherever it sits on the line 2.
Drip is not a small sprinkler. It runs at low flow for longer, and it has its own parts.
It usually gets its own zone, because its run times differ from spray and rotor zones.
University of Florida guidance notes that low-volume irrigation on shrubs or flowers works on a different schedule than rotor and spray zones 6.
This page covers drip on its own. For the lawn-style system, see sprinkler irrigation. For the whole system and what a bid should list, see our irrigation service page.
How water travels through a drip system
The parts run in a fixed order. Leaving one out is a common reason drip systems fail.
- Backflow protection. All municipal water systems require some type of anti-siphon or backflow prevention device, and the double check valve is the most common 4.
- Filter. Drip openings are tiny. A 150-mesh filter is the minimum, and some emitters need 200 mesh 3.
- Pressure regulator. It drops the pressure to what the tubing and emitters tolerate, about 30 psi for most landscape drip 3.
- Tubing. Drip tubing carries the water through the bed. Clemson says 16 mm tubing is the most popular size 2.
- Emitters or dripline. They release water slowly at 1/2, 1 or 2 gallons per hour 2.
- Flushing. Regular flushing of the lines helps prevent particles from clogging emitters 5.
- Backflow deviceProtects drinking water
- Filter150 mesh or finer
- Pressure regulatorAbout 30 psi for most tubing
- TubingCarries water to the bed
- Emitters under mulchRelease 1/2 to 2 gal. per hour
Order and numbers follow Clemson Extension fact sheets HGIC 1811, 1814 and 1816. Source: [2] [3] [4]
Emitters, tubing and tape compared
| Part | What it does | Best fit | What Clemson says |
|---|---|---|---|
| Pressure-compensating emitter | Holds steady flow across pressure changes | Uneven ground and long runs | Suits a typical landscape 2 |
| Turbulent-flow emitter | Lower cost, flow varies more with pressure | Small, level areas | Also suits a typical landscape 2 |
| Multi-outlet emitter | One body feeds five or six small emitters | Pots or several plants in one spot | Typical use is containers 2 |
| Dripline | Emitters pre-spaced at 12, 18 or 24 inches | Orchards or evenly spaced plantings | Not best for randomly spaced beds 2 |
| Drip tape | Thin-walled tape with built-in emitters | Garden rows | Needs only about 10 psi; over 15 psi can rupture it 3 |
| 1/4-inch “spaghetti” tubing | Short branch from the main line | Single plants and pots | One to two feet works on level ground; six to ten feet may not deliver water to the end 2 |
Example: laying out and timing a small bed
The numbers below are invented to show the arithmetic. The layout is Clemson’s groundcover grid 2, and the time formula is the University of Florida one for micro zones: time in minutes equals 60 times gallons divided by gallons per hour 6. The plant water need is an example only. Real needs vary.
| Item (example) | Input | Arithmetic | Result |
|---|---|---|---|
| Groundcover bed | 100 sq ft | One 1/2 gph emitter per 2 ft by 2 ft cell, which is 4 sq ft 2 | 25 emitters |
| Total flow of that bed | 25 emitters at 1/2 gph | 25 × 0.5 | 12.5 gallons per hour |
| Shrub (example need) | 3 gallons per watering | Time = 60 × 3 ÷ 2 gph (two 1 gph emitters) 6 | 90 minutes |
| Same shrub, four 1/2 gph emitters | Still 3 gallons | 60 × 3 ÷ 2 gph (four × 0.5) | 90 minutes, spread wider around the plant |
Minutes = 60 × Gallons ÷ GPH
Minutes- How long the zone runs
Gallons- Water a plant or bed should get in one watering
GPH- Total emitter flow on that zone, in gallons per hour
This is the University of Florida micro zone formula. It needs a plant water figure from a local source.
Source: [6]
The shrub need of 3 gallons is an invented figure. Ask a local extension office what your plants need. For the lawn side of the yard, use the sprinkler runtime calculator; it is built for sprays and rotors, not drip.
Where drip shows up in a yard
In planting beds. Clemson’s sheet describes a 2 ft by 2 ft grid of emitters for groundcover such as liriope 2. See planting and garden beds.
Around trees and shrubs. Emitters circle the plant within its canopy. Roots reach beyond the trunk, which the critical root zone page explains.
On an irrigation bid. A drip zone appears as its own line, with a filter, regulator, tubing and emitters. It should be on a separate valve from spray and rotor zones.
In turf rebate rules. Some water providers run turf rebate programs. Our turf rebate research shows what they cover, and your provider has the rules.
Strengths and weak points of drip
Strengths
Weak points
- Small openings clog. Filtration and flushing are not optional 35.
- Too much pressure pops emitters out of the tubing 3.
- Emitters must stay above ground. Buried ones can plug with dirt or roots 2.
- Damage is easy to miss under mulch, so beds need regular checks. EPA says to inspect irrigation systems monthly 1.
What these sources do not settle
The Clemson sheets we read date from May 2008. They are clear on parts and pressures, but they give no flow-per-foot or maximum line lengths.
Clemson’s two sheets also differ on pressure: one says drip works well at 20 to 30 psi, and the other gives 30 psi for emitter tubing 23. We show both.
The New Mexico State paper is about low-pressure gravity systems from an elevated tank. Its filter, flow and backflow points apply, but its pressure advice does not apply to a house spigot 5.
No source we read says whether drip suits turf. Clemson’s sheet addresses groundcovers and beds, and does not cover lawns 2. We do not claim it does.
We give no run times or watering amounts. They depend on plants, soil, climate and emitter flow. Local water rules also apply.
What drives the price, and what shortens or lengthens life
We publish no prices. A drip bid moves with the bed area, the number of emitters, the length of tubing, the filter and regulator quality, a controller or timer, trenching for any buried mainline, and the backflow device.
Clemson notes that simple plastic, pre-set agricultural regulators cost roughly 50 to 75 percent less than brass hardware-store models 3.
Water quality also shapes cost over time. Clemson says iron at 0.3 parts per million or more in well water will definitely cause plugging, while under 0.1 should not 2. Surface water carries sediment and algae and may need a self-cleaning or sand media filter 3.
We give no lifespan. Clemson describes drip tubing as sunlight resistant, but life depends on the product, pressure, water and upkeep, so we state no number. See the cost guide and the landscaping estimates guide.
Who installs drip, and how a job runs
A homeowner can install a small drip zone from a kit. A landscape or irrigation contractor handles larger zones and any tie to the main line.
- Choose the plants and group those with similar needs on one zone.
- Call 811 before trenching for a buried line.
- Confirm backflow rules with the building inspector or water provider. NMSU advises asking for the correct requirements 5.
- Install the backflow device, filter and regulator in that order.
- Lay the tubing, flush it with cold water before placing emitters, since a hot line shrinks as it cools 2.
- Place emitters above ground under mulch 2.
- Flush the ends, run the zone and check each emitter.
Backflow protection and utility checks come first
Drip lines on a drinking-water supply need a backflow device, and local rules decide which type 45. Call 811 before trenching.
If anyone proposes injecting chlorine or fertilizer through the lines, Clemson notes that chemical injection needs safeguards against backflow 3.
Use any product exactly as its label says, and let a licensed pro set it up.
Keeping a drip zone clean and working
Upkeep tasks are listed here without fixed dates. Water quality and mulch decide how often.
- Clean the filter. EPA says to clean microirrigation filters as needed 1.
- Flush the lines. NMSU says regular lateral flushing helps prevent particle clogs 5.
- Inspect monthly. EPA says to check for leaks and damaged or clogged parts every month 1.
- Pull tubing onto old mulch before adding new. Clemson says mulch must soak through before water reaches soil 2.
- Adjust with the season. EPA says schedules should change with the seasons 1.
- Test for iron if you use a well. Iron can clog emitters after it oxidizes 2.
Warning signs, and when to call a pro
- Plants at the end of the line look dry. Pressure may be uneven or a filter blocked. Clemson says closing a valve partway is unreliable, so the first emitters get more water than the last 3.
- Emitters popping off. Pressure is probably above 40 psi 3.
- Rusty or crusty deposits at emitters. Iron or minerals may be clogging them 25.
- Wet patches in the mulch. A split line or loose fitting may be leaking.
- Green slime in the filter. Algae from surface water can clog quickly 3.
Call an irrigation professional for backflow devices, any buried main line, or water that needs chemical treatment. See choosing a landscaping company for what to ask.
Codes, tests and local rules
Backflow rules. Clemson says all municipal water systems require some type of anti-siphon or backflow device and that South Carolina law requires devices to be tested every year 4.
That is South Carolina’s rule. Other states differ, so ask your water provider. NMSU says to contact the local building inspector or water purveyor about the right device 5.
Plumbing and building codes. Local code decides who may install a backflow device and whether a permit is needed. We found no single national rule.
Water restrictions. Drought or seasonal rules may limit when and how long you can irrigate. Whether drip is treated differently depends on the provider. Check the watering restrictions tracker linked below and your local utility.
Injected products. Fertilizer or chlorine put through a drip system falls under product labels and local rules. We do not give application rates.
Drip vs. related irrigation terms
| Term | How it applies water | Where it fits | Read more |
|---|---|---|---|
| Drip irrigation | Slowly, at the plant’s base 1 | Beds, shrubs, trees, groundcover | This page |
| Sprinkler irrigation | Sprays or streams over an area | Lawns and large beds | Linked in the first section |
| Rotor vs. spray heads | Two sprinkler head types | Different zones and rates | Rotor vs. spray heads |
| Irrigation controller | Decides when each zone runs | Every automatic system | Irrigation controller |
| Xeriscaping | A design approach, often with drip | Low-water landscapes | See xeriscaping in related terms |
Common myths about drip
- Myth Drip is install-and-forget.
- Reality EPA says to inspect irrigation systems monthly and clean microirrigation filters as needed 1. NMSU adds regular flushing 5.
- Myth Bury the emitters to hide them.
- Reality Clemson says emitters in the landscape are always placed above ground and under mulch, because buried emitters can plug 2.
- Myth Any hose-end pressure is fine.
- Reality Clemson says more than 40 psi can pop emitters out, and drip tape can rupture above 15 psi 3.
- Myth A household filter is enough.
- Reality Clemson does not recommend household sediment filters, and says drip needs a 150-mesh filter 3.
- Myth One schedule fits all drip zones.
- Reality Run time depends on emitter flow and plant need. The University of Florida gives a formula, not a universal time 6.
The regional variable: water quality and local watering rules
Two local facts change a drip system. The first is your water. Well water with iron, water with high calcium and bicarbonate, and water from ponds or ditches each clog emitters in a different way 25.
A lab test or your utility’s water report tells you which applies. The second is the rule: backflow testing, permits and watering limits vary by state and provider. Clemson’s mention of annual tests describes South Carolina 4. Check your own provider and the tracker below.
When drip is the right choice, and your next step
Drip is worth considering for beds, shrubs, trees and narrow strips, where a sprinkler would waste water on paving. It is a poor fit where you cannot filter the water or keep pressure under control.
Your next step is to list what you want to water and group plants with similar needs. Then check your water source for iron or sediment, and ask your provider about backflow rules.
If the yard also has lawn, read the sprinkler irrigation page and plan the lawn zones and the drip zones as separate parts of one system.
- If Shrubs, trees or beds with odd shapes
- Then Drip, under mulch, on its own zone 2
- If Open lawn
- Then A sprinkler zone; Clemson’s drip sheet does not address lawns 2
- If Pressure at the tap is high or unknown
- Then Add a regulator before anything else 3
- If Local rules limit watering days
- Then Check how your provider treats drip
Group plants by thirst
A zone runs every emitter for the same time. Put plants with similar water needs on the same zone so none get too much or too little.
Questions about Drip Irrigation
What is drip irrigation?
Drip irrigation is a method that sends water through tubing to small emitters, which release it slowly at the base of plants. EPA describes microirrigation as applying water slowly and directly to the roots where it is needed most. It needs a filter, pressure control and a zone of its own.
What parts does a drip system need?
A backflow device, a filter, a pressure regulator, tubing and emitters or dripline. Clemson Extension says a drip system needs a 150-mesh filter, works well near 30 psi, and uses emitters rated 1/2, 1 or 2 gallons per hour. A drinking-water supply also needs backflow protection.
How much pressure does drip irrigation need?
Clemson Extension says drip tubing and emitters work well at about 30 psi, and one of its sheets gives 20 to 30 psi. Over 40 psi can pop emitters out of the tubing, and drip tape needs only about 10 psi and can rupture above 15. A regulator keeps pressure in range.
Should drip emitters be buried?
No. Clemson Extension says emitters in the landscape are always placed above ground and under mulch. If an emitter is buried, dirt may plug the outlet or roots may grow into it. Pull tubing up onto old mulch before adding new mulch so the water reaches the soil.
Can drip irrigation water a lawn?
Our sources do not address it. The Clemson fact sheet covers drip for beds and groundcovers, and does not discuss lawns. Lawns are normally watered with sprinkler zones. A local extension office can tell you whether any turf drip product works in your climate.
How long should a drip system run?
It depends on the plant, the soil, the weather and the emitter flow, so there is no one schedule. The University of Florida gives a formula: minutes equal 60 times gallons divided by gallons per hour. You still need a plant water figure from a local source.
Why do drip emitters clog?
Common causes are sediment, algae, iron and mineral deposits. Clemson says iron at 0.3 parts per million or more will definitely cause plugging. New Mexico State says proper filtration and regular flushing prevent particle clogs, and that calcium deposits can need an acid treatment.
Do I need a backflow preventer for drip?
Usually yes if the system connects to a drinking-water supply. Clemson says all municipal water systems require some type of anti-siphon or backflow device. New Mexico State advises asking your building inspector or water provider which device applies. Rules and testing requirements vary by place.
How efficient is drip irrigation?
Clemson Extension says drip systems are typically 90 to 95 percent efficient. That means little water is lost to wind, evaporation or runoff when the system is set up and maintained properly. Leaks, clogged emitters and overwatering can erase the advantage.
How often should I maintain a drip system?
EPA says to inspect irrigation systems monthly and to clean microirrigation filters as needed. New Mexico State recommends regular lateral flushing. Seasonal changes, mulch work and water quality change how often you need to check, and EPA says schedules should be adjusted for the season.
Sources
- U.S. EPA WaterSense, Watering Tips (updated March 11, 2026), retrieved .
- Clemson Cooperative Extension, HGIC 1811, Landscape Irrigation Equipment Part 2: Drip Irrigation (W. Bryan Smith, 2008), retrieved .
- Clemson Cooperative Extension, HGIC 1814, Landscape Irrigation Equipment Part 5: Filters and Pressure Regulators (W. Bryan Smith, 2008), retrieved .
- Clemson Cooperative Extension, HGIC 1816, Landscape Irrigation Equipment Part 7: Valves (W. Bryan Smith, 2008), retrieved .
- New Mexico State University, RR-773, Low-Pressure Drip Irrigation for Small Plots and Urban Landscapes (Smeal and others, 2011), retrieved .
- University of Florida IFAS, AE220, Operation of Residential Irrigation Timers (Dukes, Cardenas and Haman), retrieved .
Expert review
Written by the HyreYard Research Desk. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Pressures, filter mesh, emitter flows and placement are from Clemson Extension HGIC fact sheets published in 2008; the two Clemson sheets differ slightly on pressure and both are shown.
Clogging, flushing and backflow points are from New Mexico State’s low-pressure drip paper, which is written for gravity systems. The micro zone formula is University of Florida’s; the page states no issue date.
The bed and shrub examples use invented inputs and labelled arithmetic. UC Cooperative Extension’s drip page returned an access error and is not cited. No run times, prices or lifespans are given.
Suggest a correction. We fix errors and say what changed.