Water Adjustments for Plant Growth
As your landscape plants grow, they will need more water. Bigger plants have larger root systems, which means they require more water.
That’s why it's a good idea to check your landscape about once a year to see if you need to change how you water. You can increase the water you give your plants by:
- Adding more emitters
- Switching to emitters that deliver more water (for example, changing from a 1-gallon per hour emitter to a 2-gallon per hour emitter)
- Watering for a longer time
- Using any combination of the first three options.
Use Table A to see if you need to give your plants more water. Table B shows you the recommended amount and size of drip emitters for different-sized plants.
How to Use the Tables
Example: You have a shrub that's four feet wide.
Using Table A: You will need 12 gallons of water each time you water it to soak the roots.
Using Table B: The recommendation is to use two or three 2-gallon-per-hour emitters for a four-foot shrub. If you choose to use two 2-gallon emitters, that means you’ll get 4 gallons of water per hour. If you run your system for 3 hours, you’ll get the 12 gallons needed. Remember, your plants can share water, so if you have a lot of plants close together, you might need to use less water for each one.
Table A: Gallons of Water Needed to Soak the Root Zone
Plant Canopy Diameter in Feet
| |
1'
|
2'
|
3' |
4'
|
5'
|
6'
|
8'
|
10'
|
12' |
14' |
16'
|
18'
|
20' |
| Trees |
1.5
|
5
|
11
|
16
|
22
|
26
|
38 |
59
|
85
|
115 |
150
|
190
|
235
|
| Shrubs |
1 |
4
|
8
|
12
|
17 |
20
|
|
|
|
|
|
|
|
| Groundcovers |
.5 |
2
|
3.5
|
5
|
7
|
9
|
|
|
|
|
|
|
|
Table B: Recommended Number of Drip Emitters
Suggested Drip Emitter Quantities
|
Canopy Diameter
|
Number of Emitters
|
Emitter Flow Rate
|
| Trees |
7 - 10 feet
|
3 - 5
|
2 - 4 gallons per hour
|
| |
11 - 14 feet
|
4 - 6
|
2 - 4 gallons per hour
|
| |
15 - 20 feet
|
6 - 12
|
2 - 4 gallons per hour |
| |
21+ feet
|
12+ |
4 gallons per hour
|
Large Shrubs
|
4 - 6 feet
|
2 - 3
|
2 gallons per hour
|
Small Shrubs / Groundcovers
|
1 - 3 feet
|
1 |
1 gallon per hour
|
If your plants have larger root systems, they can hold more water. This means that bigger plants might need more water each time you water them, but you can water them less often. When you increase the amount of water, make sure to also adjust your controller to water less frequently. If you have desert-adapted trees, they might be able to survive on natural rainfall if it’s enough.