Successful commercial irrigation relies more on effective irrigation, rather than just the time that sprinklers are on. Plants can suffer from overwatering, underwatering, improper timing, runoff, standing water and dry patches, which require more water consumption. Increased watering time will not always solve the problem since the problem may stem from blocked sprinkler heads, water pressure, compacted soil, weather conditions or selecting the wrong plants. Landscape water management needs to consider the irrigation equipment, soil and plants as well as weather to determine the actual cause, and to maintain a healthy and attractive landscape.

1.   Overwatering the Landscape

The mistake many make is that they think they need more water to have healthier plants.

Overwatering can cause excess soil moisture for extended periods of time. This may decrease the oxygen available to the roots and lead to root issues and other stressors to plants depending on plant and soil conditions.

Signs of Overwatering

When using the management software, property managers might observe:

•            Water sources that are standing or pooled water.

•            Persistently wet soil

•            Yellowing foliage

•            Weak plant growth

•            Excessive runoff

•            Moisture-related plant problems

•            Areas that wet up again after irrigation

Excessive irrigation should not be assumed to be the cause of these symptoms. Compacted soil and poor drainage can create the same situation.

Useful hint: Don't adjust the property watering schedule based on one issue. Explore the area of irrigation supply first.

2.   Watering on Plants or Turf

Too little water can also cause severe damage, especially in hot and dry weather.

Turf can turn brown or brittle, and plants can wilt, turn droop or have stunted growth. New plantings can be especially vulnerable as the root system can be less developed.

What to Check First

Instead of just watering for longer, check the sprinkler heads for the dry zone. Verify if they are working properly and if their spray is getting to the area.

If there is one point on the site that is only partially dry, it is more likely to be a localized distribution or equipment problem, rather than problems with not watering the entire site.

3.   Watering at the wrong time.

The time of irrigation (day or night) can influence the water use efficiency.

In hot, sunny weather, the amount of water that evaporates may increase as well. The wind can also disrupt the pattern of water emitted by sprinklers and push water off target.

In many landscapes, there may be some losses through evaporation during periods of watering that are cooler. There isn't a single schedule that is suitable for each property, however.

All these factors should be taken into account: weather, soil, requirements of the plants, local regulations and equipment for irrigation.

Expert insight: Automation must be used to complement, and not supplant, good irrigation management. An automated system can still water a landscape too much if it isn't configured properly.

4.   Failure to address unequal distribution of water.

An irrigation system may look fine and sound good, and yet fail to provide the required water supplies in different areas of the landscape.

This frequently manifests in some regions staying healthy while others are dry patches, or too wet.

Common Causes

There may be uneven distributions due to:

•            Blocked sprinkler heads

•            Broken sprinkler heads

•            Misaligned nozzles

•            Incorrect sprinkler spacing

•            Poor water pressure

•            Damaged pipes

•            Poorly configured zones

•            Changes to the landscape

The topography of a property can also be altered by buildings, old trees and new planting.

Changes that can be seen by the property managers.

If possible and safe, monitor the system when it is in service.

Check for defective sprinkler heads that don't turn on, spots that aren't being watered, a lot of misting, and water that is running on the pavement or areas that don't get much water.

A second irrigation assessment can be useful if the problem persists to determine the problem is on the pressure, distribution, equipment or system design.

5.   Leaving the height and width of the fence as they are.

The amount of water a landscape needs may vary from season to season.

Using an identical irrigation schedule regardless of temperature, rainfall and plant activity can result in inefficient watering.

In warm and/or dry conditions, plants may need additional available moisture. The same schedule can turn out to be too much when temperatures drop or it rains more.

What to think about?

Adjustment(s) to irrigation during the season may consider:

•            Temperature

•            Rainfall

•            Evaporation

•            Soil moisture

•            Plant requirements

•            Local weather conditions

Property managers should routinely adjust the settings on the controller, rather than relying on an outdated schedule.

When properly installed and maintained, a rain sensor and a controller that are based on the weather can help with this process.

The idea is not to be bound to a set schedule. The intent is to answer the real landscape situation.

6.   Failure to maintain Irrigation System.

Even a well-designed irrigation system can become inefficient when parts of the system are neglected.

The sprinkler heads may clog or damage. Valves can malfunction. Pipes can leak. Controllers may have old schedules and sensors may lose reliability with information.

These issues may lead to water loss, or lead to imbalanced conditions in the landscape.

Components Worth Inspecting

Regular inspections may include:

•                    Sprinkler heads

•                    Nozzles

•                    Valves

•                    Pipes

•                    Filters

•                    Controllers

•                    Pressure regulators

•                    Rain sensors

•                    Soil-moisture sensors

•                    Flow-monitoring equipment

•                    Watch for Changes

Instead of waiting until the landscape dies back, property managers should monitor changes in landscape performance.

If for instance there are sudden spikes in water use, when there are dry spells then there is water, when there is water, there is water, then there is more, then there is more, then there is more, then there is more, it is worth another look.

Preventive maintenance isn't a way of replacing equipment without need. It involves recognizing issues and deciding if the issue can be cleaned, adjusted, repaired or replaced.

7.   Watering the same amount and frequency throughout the season

In a large landscape, one of the most common errors is to assume that all areas of the landscape are the same.

The same amount of water is not required for a planted understory under a tree versus a brand-new shrub or for a sloped bed versus a flat bed.

Why Irrigation Zones Matter

Zoning irrigation can enable watering to be tailored to:

•            Plant type

•            Sun exposure

•            Soil conditions

•            Drainage

•            Landscape location

•            Water requirements

This can be especially beneficial for homes that have multiple landscaping styles.

Consider Soil Conditions

Irrigation performance is also influenced by soil.

Compacted soil can also be less permeable for infiltration, and sandy and clayey soils can have different infiltration and retention characteristics. Water may also be lost from sloped areas before it reaches the target root zone due to runoff.

So, longer irrigation periods are not necessarily the right answer for dry vegetation.

When the problem is not the irrigation system.

An important component of a good landscaping steward is understanding that plants that are not healthy do not necessarily mean that there is an irrigation problem.

Other potential issues are:

•            Poor drainage

•            Compacted soil

•            Plant disease

•            Pest activity

•            Nutrient deficiencies

•            Excessive shade

•            Root-zone problems

•            Unsuitable plant selection

•            Physical damage

That is why it is not always beneficial to make irrigation changes over and over, without understanding the symptoms.

A well-done assessment takes a holistic approach to the landscape.

Effective water management can be achieved through smart irrigation technology.

Larger landscapes may benefit from the use of technology to provide useful tools for managing the landscape.

Smart controllers can program schedules and (depending on the system) include weather data. The soil-moisture sensor can help monitor soil moisture, and the rain sensor can help prevent unnecessary irrigation after rainfall.

Flow monitoring can also alert property managers to unusual water usage, which could be a sign of a leak or a system issue.

But technology is no magic bullet.

Sensors must be properly installed, equipment must be properly maintained and the controllers must be programmed correctly. Smart technology is most effective when used as part of an over-arching irrigation management program.

When to adjust, repair or replace a structure or component, and how to make the decision.

When irrigation problems recur, it does not necessarily mean that the entire system must be replaced.

Some problems can be addressed by more narrowly targeted actions like:

Clean clogged sprinkler heads:

•            Replacing damaged nozzles

•            Adjusting spray patterns

•            Repairing leaks

•            Correcting controller settings

•            Replacing faulty valves

•            Modifying irrigation zones

In these instances, a bigger upgrade may be warranted when the system is obsolete, the topography may not support the system, or the system's coverage may be inadequate.

The choice should be made according to the condition of the system and the needs of the building and not based on the premise that new equipment is always superior.

A Practical Irrigation Inspection Checklist is available.

When inspecting the landscape for watering, managers can refer to the following checklist:

•                    Look for damage or clog in sprinkler heads.

•                    Check for any visible leaks.

•                    Check places where water is standing.

•                    Check for areas that are dry all the time.

•                    Review controller schedules.

•                    Check to see if settings match current conditions.

•                    Where possible, see sprinkler coverage.

•                    Check available valves and parts.

•                    Keep an eye out for unusual increases or decreases in water use.

•                    Check irrigation zones following changes in landscaping.

•                    Do not constantly change the timer if it is causing a recurring issue.

For complex commercial systems, an in-depth assessment by a professional may be warranted when a problem can't be found by simple observation.

Frequently Asked Questions

•                    How many times a week should a commercial landscape be watered?

There is no one-size-fits-all answer for how often to water. Requirements are based on the weather, plant types, soil, drainage, landscape design and irrigation system. Schedules should be flexible and change as needed, not as the calendar dictates throughout the year.

•                    What are some indicators of an inefficient irrigation system?

Dry patches, excessive run-off, standing water, irregular plant growth, signs of leaks or unusual water usage may signify issue. Before making significant changes to the schedule, the specific cause should be investigated.

•                    Does over watering cause more problems than under watering?

Both can have a negative impact on landscapes. Excessive watering may lead to related root and soil issues, while insufficient watering could result in stress and less than optimal growth. The required quantity is dependent on the landscape and environmental conditions.

•                    How can smart irrigation systems contribute to water savings?

Watering can be more responsive with smart controllers, sensors and monitoring devices. They will only function properly if they are installed, programmed, maintained and used properly for the property's conditions.

•                    Does watering have to be the same throughout the whole area?

Not necessarily. Water requirements can vary depending on the types of plants, soil, sun exposure, and drainage. A proper subdivision of the landscape to separate irrigation zones can offer more control.

•                    When is it time to have an irrigation system professionally evaluated?

Consider professional assessment when problems persist, water usage changes unexpectedly, coverage is uneven, leaks repeatedly occur or the existing system no longer suits the landscape.

Conclusion

It takes more than just setting an irrigation timer and letting it stay the same to keep your commercial landscape vibrant. Watering effectively requires knowledge of plant/soil/weather, irrigation equipment and site conditions.

Poor watering practices such as overwatering, underwatering, improper timing, uneven watering, incorrect seasonal watering, and improper maintenance and watering schedules can be problematic for a landscape. But not all plant health problems are related to irrigation.

The most effective way is to first determine the problem and then adjust the watering schedule or purchase new equipment. Some problems may be solved by making simple changes, some may be a recurring problem, or a complex problem may need a professional assessment.

A commercial irrigation system that is properly managed should meet the true needs of the landscape. By conducting regular inspections, making sensible scheduling decisions, zoning and providing timely maintenance, property managers can help to make outdoor spaces healthier, more consistent and more efficient to manage.