How to Space Irrigation Sprinklers

With the exception of perennials and a few other plants, your irrigation system will require adjustments to best suit what you're growing. An ideal micro irrigation system will deliver water where it's needed most--the roots. A well-designed irrigation plan will provide the right mix of water and air in the soil so your plants will have the optimal growing conditions. The placement of sprinklers and other water outlets is crucial. Here's how to do it.

Difficulty: Moderate

Instructions

Things You'll Need:

• Irrigation sprinklers (or other type of emitters)
• Anchors or pins

Know Your Plants

1. Determine how much water your plants need before you water them. For instance, shallow-rooted plants (vegetables, for example) require short, frequent watering, while deep-rooted plants (like trees) grow better with long, slow irrigation. New plantings need sprinklers or drippers above the root ball.

2. Evaluate the conditions of your soil. Sandy ground and plants that grow in them--like palm trees--need lots of water because it washes through quickly. Soils that are more clay-like don't drain as quickly and may become flooded under the same watering conditions.

Know Your Emitters

3. Pick appropriate emitters. Water emitters may take the form of sprinklers, drippers, jets or bubblers, each with their own way of distributing water. Know their differences and compare them to the needs of your plants and the soil (see Resources below).

4. Get more emitters for larger plants. Generally, bigger plants means bigger root systems and therefore more water is required. For trees, start with low-flow emitters and increase the flow (but not the number of emitters) as the tree gets larger.

5. Space emitters about a foot apart in sandy conditions, as a general rule. Space them 2 feet apart in clay-like conditions, and space them in between for conditions that fall in the middle of this spectrum. The flow capacity of the emitters will vary by plant type and other factors.

Tips & Warnings

• It is better to err on the side of not enough watering than too much watering.
• Indicator flags show when water emitters are working, an easy way to check the effectiveness of your irrigation system.
• Micro irrigation systems are easy to change or add on to as your garden grows. For very low-flow systems, add an extra emitter in case one fails or becomes clogged.
• Because micro irrigation systems are on or under the ground, you cannot visually check how effective the watering system is. Instead, check the progress of the plant itself.

Resources

• For more on emitter types