Spring changes the watering conversation.
After winter, when excess moisture can be a bigger concern than a lack of it, longer days, warmer temperatures, and returning growth gradually increase the amount of water your lawn uses.
But that doesn’t mean the irrigation needs to go back on as soon as September arrives.
Spring rainfall may still be doing plenty of the work for you, particularly early in the season, while different soils and lawns will dry at very different rates. Add spring lawn renovations into the mix and two lawns next door to each other could have completely different watering requirements.
The trick is knowing what your lawn needs, what the weather is already providing and when you actually need to step in.
Does your lawn need watering in spring?
Not always.
An established lawn may receive everything it needs from rainfall for parts of spring. As temperatures rise, growth increases and the time between rain stretches out, supplementary watering becomes more likely.
Spring tells you that your lawn's water requirements are beginning to change. Your lawn and the conditions tell you when it's time to step in.
Consider:
- How much rain have you had recently?
- Is there still moisture below the soil surface?
- Is the lawn actively growing?
- Are conditions becoming warmer, drier or windier?
- Is your lawn established or newly seeded?
- Does your soil tend to drain quickly or hold moisture?
How can you tell if your lawn needs water?
Don't judge moisture by the surface alone.
The very top of the soil can look dry while useful moisture remains within the root zone. Before turning on the sprinkler, take a closer look below the surface.
A finger, small trowel or screwdriver can help you get a better idea of how much moisture remains in the soil.
The grass itself can also provide clues. As moisture becomes limited, you may notice the lawn losing some of its usual firmness or footprints remaining visible for longer after you've walked across it.
The aim isn't to wait until the lawn is severely stressed. It's to become better at recognising when available moisture is starting to run low.
The LAWNZ Spring Moisture Check
For an established lawn, before turning on the sprinkler, check the soil below the surface.
Is the soil still damp?
YES → Hold off watering.
Your lawn likely has enough moisture for now. Check again as conditions change.
NO → Take a closer look at the grass.
Is it beginning to show signs of moisture stress, such as footprints that remain visible or leaves losing their usual firmness?
YES → It's time to water.
NO → Hold off for now.
Keep an eye on the lawn and check the soil again soon.
Remember: recent rain may keep the soil damp for longer, while warmer, drier or windier weather can mean it's worth checking again sooner.
New seed and established lawns need different watering
This is one of the most important distinctions to make during spring.
Renovation and overseeding season means you may have newly sown grass sitting alongside an established lawn, but they shouldn't be watered in the same way.
Watering an established lawn
An established lawn has a developed root system capable of accessing moisture further down in the soil. When additional water is required, aim to get moisture into the root zone rather than repeatedly wetting only the surface.
There isn't one spring watering schedule that works for every lawn. Rainfall, temperature, soil type and exposure all influence how quickly water is used or lost, so some drying between watering is normal.
Watering new grass seed
Newly seeded lawns are different.
During germination, the seed and upper layer of soil need consistent moisture. New seedlings don't yet have an established root system capable of accessing water further below the surface, so lighter, more frequent watering may be needed, particularly during warm, dry or windy weather.
As the grass establishes and its roots develop, you can gradually transition towards the deeper, less frequent watering approach used for an established lawn.
Spring rain still counts
It sounds obvious, but it's easy to forget once an irrigation routine starts.
Rainfall contributes to the moisture available to your lawn. If you've had useful rain, you may be able to delay or skip your next planned watering.
This is particularly relevant with automatic irrigation systems, which can continue operating regardless of what's fallen from the sky unless they're adjusted.
A wet spring may require very little supplementary watering for an established lawn. A warm, dry spring could require you to intervene sooner.
The season provides the framework. The weather determines the details.
Your soil changes the way you water
Two lawns receiving exactly the same amount of water won't necessarily hold onto it for the same amount of time.
Free-draining or sandy soils
Water can move through these soils relatively quickly. They may dry sooner and require closer monitoring as temperatures increase.
Heavier soils
Heavier soils generally retain moisture for longer, which can reduce how frequently additional water is required. They can also remain overly wet if irrigation is added when the soil is already holding plenty of moisture.
Compacted soils
If water pools or runs across the surface rather than soaking in, the problem may not be how much water you're applying.
Compaction can make it more difficult for water to penetrate effectively into the soil.
In that situation, simply running the sprinkler for longer isn't necessarily the answer. Addressing the underlying soil condition may be more useful.
Get to know your sprinkler
Not all sprinklers deliver water at the same rate or distribute it evenly across a lawn.
A simple rain gauge or a few straight-sided containers placed around the lawn while you water can help you see what's actually happening.
Check the containers after watering. If some contain considerably more water than others, your sprinkler may not be covering the lawn evenly. You can also use them to get a better sense of how quickly your sprinkler is applying water, rather than relying on how long it has been running.
Once you understand how your sprinkler performs, it's much easier to adjust how you use it as your lawn's needs change.
When is the best time to water your lawn in spring?
When your lawn does need supplementary water, morning is generally the best time to apply it.
Watering earlier in the day gives moisture an opportunity to reach the soil before warmer daytime conditions increase water loss, while allowing wet leaf surfaces to dry as the day progresses.
This becomes particularly relevant as spring brings the combination of increasing temperatures and moisture that can favour some lawn diseases.
Where possible, also avoid watering in particularly windy conditions. Wind can increase moisture loss and interfere with sprinkler distribution, leaving some areas receiving considerably more water than others.
Common spring watering mistakes
Turning the irrigation on because it's spring. Spring is your cue to start paying closer attention to moisture, not necessarily to start watering.
Treating new seed like an established lawn. New seed needs consistent surface moisture while germinating; established grass can access water further below the surface.
Watering little and often. For an established lawn, aim to get water deeper into the soil where the lawn's roots can access it, rather than repeatedly wetting only the surface.
Ignoring rainfall. If nature has already watered the lawn, take that into account before adding more.
Judging moisture from the surface. Check what's happening below before deciding your lawn needs water.