Watering Tips and Practices
How often, for how long and at what time:
How often will depend on average rainfall, average temperature, humidity levels, soil type, and the systems precipitation rates. The old rule of water deeply and infrequently doesn't apply to every situation. Different soil types require different irrigation methods.
How long will depend mainly on soil content and sun exposure.
Heavy clay soils soak up water at a slower rate than sandy or loamy soils. If you water too long a heavy clay soil will leave you with wasteful runoff, pooling, weeds and unhealthy plants. Most modern central controllers have multiple start times and some have a cycle and soak feature to allow for more efficient watering. We can provide you with a soil analysis to determine your best options for healthy watering practices.
Sun exposure is another part of the equation. Your landscape and your irrigation system should be broken up into hydra zones. Areas that receive more sun need more water and areas with more shade need less water. The system should be designed with different zones to accommodate these different exposures and needs.
The best time to irrigate your landscape is early in the morning 2-3 hours before sunrise. This is the coolest part of the day and there are typically zero wind conditions. This allows for two things. The water has plenty of time to soak in before the sun starts to evaporate it and the system is most effective in coverage during zero wind conditions.
If you have a lot of different zones, more than 6, you will have to make adjustments to your irrigation schedule.
Can I water trees, shrubs and turf grasses on the same zone?
You can, but its not a good idea. The root structures of trees, shrubs and grasses vary greatly. Watering all these plants at the same time may provide enough water for one type of plant and not nearly enough for another. Turf grasses have a root structure that extends only 3-6 inches deep. Trees and shrubs have root structures that are 3-4 times deeper. If you water everything on the same schedule you'll have healthy grass and unhealthy trees and shrubs or just the opposite. A design feature also needs to be considered with this rule. You'll find that after several years the foundation plants are established and wont' need any supplemental water. If the system is designed well you can eliminate the foundation zone from the irrigation schedule and save water.
Fact- More plants die from over watering than under watering every year.
The simple fact is that most trees, shrubs and plants die from too much water than not enough. Deep and less frequent waterings teach roots to grow down to look for moisture. During periods of drought well trained roots will look deeper into the soil for moisture reserves. Shallow trained roots will look to the surface, find nothing, and the entire plant will suffer or die.
The soil conditions also have a lot to do with plant survival. If you have a heavy clay content in your soil you must take extra steps to amend the soil prior to planting. By adding soil conditioner, nature's helper, compost, or any other soil amending product you allow for the soil around the root ball to remain moist but not saturated. Root rot is the primary culprit in the death of plants and this rotting is the result of too much water and not enough air.
For a quick soil test take a handful of your existing soil and squeeze it in your fist. If you're left with a dense clump you need to amend your soil. A soil that clumps but falls apart at the slightest touch is ideal. This type of soil will give the root structure room to grow and will hold the right amount of air and water to allow for healthy plant growth.
Why Drip Irrigation?
Water is the most precious natural resource we have. Without it nothing survives and it is therefore the "nectar of life". Only 2.5% of the worlds water is available for drinking water. Of that, 70% is tied up in polar ice caps and the majority of what is left over is present in underground aquifers and general soil moisture. This leaves >1% of the water readily available for human consumption.
A staggering 50% of water usage can be from irrigation during the growing season.
This consumption can be greatly reduced through the use of proper irrigation scheduling, drip irrigation or point source irrigation. A quick example to consider:
The average individual zone in this area uses 16 gallons per minute for plants and grass. The average zone runtime averages anywhere from 20 to 40 minutes. At that rate, and scheduled to run 3 times per week, you use 960-1920 gallons of water per week, 3840 to 7680 gallons per month per zone. Now imagine taking a 10 minute shower 11 times everyday. Seems wasteful doesn't it.
Individual plants only require water at the root zone to maintain plant health. This is how drip irrigation works. Water is distributed directly to the root zone at a slow soaking rate. Drip zones are rated in gallons per hour as opposed to gallons per minute. A quick example to consider:
100 plants with 5 GPH emitters runs for 30 minutes 2 times per week. That is only 500 gallons per week or 2000 gallons per month.
The water distribution is slow and methodical targeting only the vital root zone of each plant. Add a rain gage to the system and you could use even less water.
A drip zone can reduce water usage by up to 70% resulting in healthier plants and less weeds in the flowerbeds.
As for the grass use the foot rule. When you can walk across the grass and your footprint remains it is time to water. Most established warm season grasses will often go dormant during periods of drought. The slightest bit of rain usually greens them right back up.
The most efficient way to water grass is to have head to head, 100% overlap coverage. This isn't always possible. The good news is that many of the newer rotor type heads are excellent at in-close watering. Its one more reason we prefer RainBird.
The most efficient way to water trees and shrubs is drip irrigation. The upfront material cost is higher for this type of irrigation but in just 2-3 years you will have paid for the difference through reduced water bills.