That only tells part of the story.
The more useful question is this: how much water does it take your business to produce one saleable unit?
Because if you are serious about both sustainability and margin, that is the number that matters.
A nursery can look productive on the surface while quietly losing profit through poor irrigation scheduling, uneven application, runoff, nutrient loss and inconsistent crops. NIASA is clear that irrigation needs to match the crop, with uniform distribution and proper scheduling, not habit based watering.
Water waste usually starts with “the way we have always done it”
The Nursery Industry Water Management Best Practice Guidelines point out that poor irrigation is one of the biggest drivers of inconsistency in production. Both under and overwatering impact performance. Uneven application leads to uneven uptake, uneven growth and avoidable losses.
So reducing water per unit is not about using less for the sake of it. It is about applying the right amount, at the right time, in the right way. That is where tighter production systems make a real difference.
The biggest gains are usually operational, not dramatic
Most nurseries do not need to rip out their entire irrigation system to improve water use efficiency. But they do need more control.
1. Start measuring what matters
If you are not measuring application rates, runoff, leaching or irrigation performance, it is difficult to make confident irrigation decisions.
Leaching fraction is one of the most practical indicators. Many fixed sprinkler systems push far more water through the pot than needed. A target of 20% or less is a solid benchmark once scheduling is tightened.
If water is draining out the bottom of the pot, you are not just losing water. You are losing fertiliser and control of the root zone.
2. Fix irrigation uniformity
You cannot irrigate efficiently if your system is not delivering water evenly.
The Water Management Best Practice Guidelines recommend a Coefficient of Uniformity above 85% for fixed overhead sprinklers, with a Scheduling Coefficient below 1.5 to reduce variation across the block.
If your driest plants are dictating the whole run time, the rest of the crop is often being overwatered to compensate.
That is where avoidable inefficiency starts to build.
3. Stop watering whole zones like they are all the same crop at the same lifecycle stage
One of the most common inefficiencies in production nurseries is grouping unlike crops under the same watering regime.
The guidelines are clear: divide the nursery into areas with similar needs such as propagation, shade, hardening and finishing, then choose irrigation systems and schedules to match.
A freshly potted liner, a finished shrub and a larger advanced container should not be watered the same way.
Better scheduling is where the real gains are
Irrigation scheduling is one of the most commercially important tools a nursery has, and one of the most underused.
NIASA defines irrigation scheduling as replenishing the precise amount of water lost from the container since the last irrigation event, then applying that volume at the correct time. Done properly, it saves water, labour, energy and nutrients while improving yield and plant quality.
That is the real opportunity.
Because when you reduce water use per unit produced, you are usually also improving:
Runoff is not just waste, it is lost margin
Runoff is often treated as a drainage issue. But in most cases, it is a sign something upstream is not right.
Over application. Poor capture. Weak system design.
The industry water guidelines recommend capturing the first 10 to 15 minutes of runoff, as this is often the most nutrient and debris rich portion, and monitoring stored water so nutrient value can be reused where appropriate.
If water is leaving the production area carrying fertiliser, sediment or chemicals, margin is leaving with it.