Designing Your Drip Irrigation System

Creating your own drip irrigation system is a great investment for all kinds of gardens and landscapes. By delivering water slowly and directly to the root zone of your plants, drip irrigation will keep your vegetation hydrated with much less water waste. But before you get started, let’s dig into the basics of designing a drip irrigation system.

In this guide, we’ll walk through the key steps and considerations to help you plan and design a drip irrigation system that provides years and years of quality watering.

Browse Drip Irrigation Supplies & Kits At Sprinkler Warehouse

The first step in the drip irrigation planning process is gathering the necessary materials to set up your new system. Depending on the size of your watering area and the plants that you’ll be watering, requirements may vary. Here is a quick breakdown of the essentials:

• Mainline tubing – Poly tubing is the backbone of your system, carrying water from the source to various zones.
• Drip emitters – Drippers control the amount of water released to each plant.
• Microtubing – This thin tubing connects emitters to individual plants.
• Fittings – Connectors such as tees, elbows, couplings, and end caps are necessary to branch, connect, and close off tubing.
• Backflow preventer – These devices keep irrigation water from siphoning back into your household supply.
• Pressure regulator – One of these devices will ensure that water pressure stays within the range that drip components are designed for.

Keep in mind that there’s no one-size-fits-all answer. It’s usually best to calculate based on coverage area and plant spacing. Try to draw a rough diagram of the area you’d like to water (artistic skills not mandatory). This will help you determine the length of tubing and the number of emitters you’ll need.

Setting up a Drip System

Once you’re equipped with the necessary materials, it’s time to build your irrigation system. The first step is to attach a backflow preventer and pressure regulator to your water source, then connect and lay out the mainline tubing along your garden beds. Use fittings like tees and elbows to branch or turn the tubing where needed, and insert connectors at each plant location. From each of these, run microtubing to the plants and attach drip emitters near the root zones. After that, all that’s left is to cap the ends of your lines, flush the system, and then test to make sure each emitter delivers water evenly. Feel free to adjust your emitter placement or quantity as needed to match your watering area.

For more detailed, step-by-step instructions on how to install a drip irrigation system, you can read our Step-By-Step Drip Irrigation System Installation Guide.

What Type of Drip Emitter Do Perennials Need?

Perennials generally do best with low-flow drip emitters that provide a steady, deep watering rather than short, shallow bursts. This encourages strong root growth without waterlogging the soil. You’ll want at least two emitters near the base of each little green darling, 0.5-gallon, i.e., half-gallon per hour flow rate. Perennials usually require about two gallons of water a week. But that can vary depending on the size and species of your plant and the quality of your soil.   Don’t let the decisions you’re making here overwhelm you.  You can quite easily adjust the flow rate, add extra emitters, or remove emitters, even long after you’ve installed the system.  Nothing here is set in stone.  You’ll make adjustments depending on how your plants respond.

Drip Emitters for Shrubs & Trees

Onto shrubs and trees. When it comes to trip irrigation for trees and shrubs, the goal is to reach the entire root zone. Here we’ll place two emitters, the one-gallon-per-hour type, twelve inches from the base of each tree and shrub five feet or shorter. A shrub taller than five feet should have three one-gallon emitters.

A tree between 5 and 10 feet in height will need two to three 2-gallon emitters. Trees between 10 and 15 feet will need two 4-gallon emitters. Between 15 and 25 use four 4-gallon emitters. Trees taller than 25 feet are not the best candidates for drip irrigation.

Drip Irrigation for Flower Beds

For all the green stuff growing close together, you’ll utilize emitter tubing or soaker hoses.  These water an area of four to six inches on both sides of the hose.  These are also fantastic if you’re doing a vegetable garden in rows.  For those areas, draw on your diagram the hose you think you’ll need.  Then head outside and measure the length of hose your bed or garden will require.

Now we haven’t discussed emitter types or hose types yet.  We’ll get to all that in another video. (Here’s the link to an article about drip emitter types.) If you’re using a drip line, emitter tubing, or soaker hose, we’ll have a separate video on how to determine your gallons per hour flow rate.

Determine The Required Flow Rate For Your Drip Irrigation System

It’s important that we determine the gallons per hour flow rate needed for our system.  If we overtax our system, it won’t work effectively, and your plants will feel neglected, and nobody likes a sad hydrangea…

Count how many of each emitter you have grouped by flow rate.  So in this diagram, I have twenty-five half-gallon-per-hour emitters. Fifty 1-gallon per hour emitters and twenty 4-gallon per hour emitters.

Time to start figuring. That’s twenty-five times 0.5 equals 12.5 gallons per hour. Fifty times 1 gallon per hour equals 50 gallons per hour. And twenty times 4 equals 80 gallons per hour. Add those together, and I get 142 gallons per hour. I wonder if my home flow rate is enough? Most homes have a flow rate of 200 gallons per hour, so I’m probably fine.

Plan for Future Expansion

You never know when you’ll want to add more to your drip irrigation system, so try to plan ahead! For example, if you think you’ll add more plants or extend into another bed, consider using a larger diameter mainline. With a larger irrigation system, thicker tubing can handle the extra flow without losing pressure.

If you’re mixing plants with very different watering needs, it may even be worth it to divide your system into multiple zones. Plus, leaving space for an extra valve or controller connection now makes it much easier to create a new zone later.

With just a few preemptive adjustments, your system won’t be locked into today’s layout. You and your drip system will be able to adapt as your garden grows or changes.

Shop Drip Irrigation Supplies at SprinklerWarehouse

Remember,  Sprinkler Warehouse has everything for your irrigation needs. So, your trees, lawn, flower beds, and gardens are lush and beautiful. And if you have any questions about drip irrigation installation, chat with one of our incredible customer service agents on SprinklerWarehouse.com. They really know their stuff, and they’ll get you squared away. Please subscribe to our YouTube channel to learn more about irrigation and sprinkler systems. For Sprinkler Warehouse, I’m Alfred Castillo, your Sprinkler Warehouse Pro!