Preparing Your Garden for a Hot, Dry Summer: Get Ready Before the Water Runs Short

Summer is when we spend the most time enjoying our gardens — but it is also when our gardens can need the most water.

Longer days, warmer temperatures, drying winds and reduced rainfall can quickly take moisture out of the soil. If you wait until plants are wilting before thinking about irrigation, you are already playing catch-up.

The good news is that there are several simple things you can do before the hot weather arrives to help your garden cope with dry conditions.

From mulching and improving your soil to installing dripperline/dripline irrigation and setting up your watering schedule, a little preparation can make your garden easier to maintain and help you make better use of the water available to you.

1. Start with the soil

Before adding more irrigation, look at the soil itself.

Healthy soil with good organic matter can hold moisture while still allowing excess water to drain away. Adding compost or other suitable organic matter can improve soil structure and water-holding capacity.

If your garden soil becomes hard and dry in summer, water may also have difficulty penetrating evenly. Preparing the soil before summer can therefore be just as important as installing irrigation.

If you're establishing a new garden bed, consider:

• Adding compost or suitable organic matter

• Improving compacted soil

• Removing competing weeds

• Grouping plants with similar water requirements

• Choosing plants suited to your local conditions

• Installing irrigation before planting where possible

2. Mulch, mulch and more mulch

One of the simplest ways to help a garden cope with dry weather is to cover the soil.

Mulch provides a protective layer over the soil surface. It can help reduce evaporation, moderate soil temperatures, suppress weeds and improve soil condition as organic mulches break down. Watercare recommends mulch as one of the straightforward ways households can use water more efficiently in the garden.

There are plenty of options, including:

• Bark

• Wood chip

• Compost

• Straw

• Leaf litter

• Other suitable organic mulches

The depth required depends on the type of mulch you are using. Avoid piling mulch directly against plant stems or tree trunks, as this can create other problems.

Mulch and irrigation work particularly well together

If you are installing dripline, don't think of the two as alternatives.

Dripperline delivers the water. Mulch helps keep it in the soil.

The combination can be particularly useful in garden beds, around shrubs, hedges and other established planting.

Just make sure your dripperline is positioned so the water can actually reach the soil and root zone. Avoid installing it where weed mat or other impermeable materials will interfere with water movement.

3. Put your dripperline in the right place

One of the biggest mistakes with drip irrigation is assuming that putting the line somewhere near a plant is enough.

The aim is to distribute water through the active root zone.

For rows of plants or closely spaced garden planting, dripperline can be laid in parallel runs through the bed. The spacing between runs needs to take account of the soil type and the plants being watered.

For individual shrubs or trees, dripperline can be arranged around the plant rather than simply placed directly against the trunk.

As plants grow, their root systems extend beyond the immediate base of the plant. Irrigation should therefore be positioned to wet the area where the active roots are, rather than keeping everything concentrated in one tiny spot.

For larger plants, a loop of dripperline around the root zone can be useful, with additional loops possible as the plant grows.

Don't put the dripper right against the trunk

For trees and larger shrubs, avoid placing emitters directly against the trunk.

The objective is to wet the surrounding root zone, not the trunk itself.

As a general principle, think about where the roots are, rather than simply watering at the base of the stem.

4. Choose the right dripperline for the job

Not all dripperline is the same. Dripperlines can differ in:

• Emitter spacing

• Emitter flow rate

• Pressure requirements

• Pressure compensation

• Maximum recommended run length

• Suitability for different water qualities

• Above-ground or below-ground applications

  
  

For example, a dripline with emitters every 300mm and another with emitters at a different spacing will distribute water differently.

This is why it is important to design the system around the garden rather than simply buying a roll of dripperline and laying it out.

5. Don't forget filtration and pressure regulation

This is particularly important if your irrigation system is supplied from a rainwater tank, bore or pump.

Drippers have small passages and can block if sediment or other particles enter the system. A suitable filter should therefore be installed before the dripperline.

Pressure also matters.

Too much pressure can damage dripperline, while insufficient or inconsistent pressure can result in uneven water distribution.

A properly designed system will take the available pressure and flow into account and use appropriate pressure regulation where required.

If you're using tank water

Tank water can contain fine sediment, particularly if the tank hasn't been cleaned for some time.

If you are installing irrigation from a rainwater tank, make sure the pump, filtration and irrigation system are appropriately matched.

6. Keep your runs within their design limits

It's tempting to keep adding dripperline until you've covered the whole garden.

But every metre of pipe and every emitter adds to the water demand.

If the system is too large for the available flow or pressure, the emitters at the far end may not deliver the same amount of water as those closer to the supply.

The manufacturer's recommended maximum run lengths should always be followed.

For larger gardens, it is usually better to divide the your irrigation into separate zones rather than trying to run everything at once.

For example:

Zone 1: Vegetable garden

Zone 2: Garden beds

Zone 3: Hedge

Zone 4: Fruit trees

Zone 5: Lawn

This allows different areas to be watered according to their requirements and the types of irrigation running (e.g., pop-up lawn rotors, vs. dripperline).

7. Water at the right time

When you water matters.

For most garden irrigation, early morning or evening is preferable to watering during the hottest part of the day, as this can reduce evaporation losses.

With automated irrigation, early morning is often a particularly convenient option.

But don't assume that watering at night is always better simply because it is cooler. The objective is to provide water effectively while avoiding unnecessarily prolonged periods of leaf and surface wetness.

For dripperline, because water is being delivered close to the soil surface or below mulch rather than sprayed into the air, evaporation can already be reduced compared with overhead irrigation.

8. How long should you run your dripperline?

This is probably the question we get asked most often — and unfortunately there isn't one answer.

“Run your irrigation for 20 minutes” isn't a suitable rule for every garden.

The correct irrigation duration depends on:

• Dripper flow rate

• Number of emitters

• Emitter spacing

• Soil type

• Plant type

• Plant maturity

• Weather

• Slope

• Available water pressure

• How much moisture is already in the soil

  
  

A useful starting point is to run the system and then check the soil.

Don't judge the effectiveness of irrigation by looking only at the surface.

Dig down into the soil around the plants and see how far the moisture has penetrated. Regional guidance recommends checking that watering has penetrated into the soil rather than simply wetting the surface.

Then adjust your irrigation duration and frequency accordingly.

Longer and less frequent is often better than constant short watering

For established plants, repeated tiny watering sessions can encourage moisture to remain concentrated near the surface.

Where appropriate for the plant and soil, deeper watering with adequate time between irrigation events encourages moisture further down into the soil.

Newly planted plants and seedlings are different. Their root systems are still developing and they may need more frequent attention until established.

9. Don't water just because the timer says so

One of the biggest advantages of an automated irrigation system is convenience.

But automation shouldn't mean switching the system on and forgetting about it.

Your irrigation schedule should change with the weather.

If you've had significant rainfall, you may not need to irrigate.

If the weather becomes particularly hot, dry or windy, plants may need more water.

If the weather cools down, the irrigation schedule may need to be reduced.

A rain sensor or smart irrigation controller can help automate some of this adjustment, but even a simple timer should be checked regularly.

10. Check your irrigation system before summer

Before the first really hot spell, turn the irrigation system on and walk around the garden.

Check for:

• Blocked emitters

• Leaking joins

• Kinked dripperline

• Damaged pipe

• Disconnected fittings

• Uneven water delivery

• Areas that are receiving too much water

• Areas that are receiving too little

• Plants that have outgrown their original irrigation layout

  
  

If you haven't used the system for several months, flushing the lines is also a good idea.

Flushing helps remove accumulated sediment and debris that could otherwise contribute to blocked emitters.

11. Make the most of your rainwater

If you have a rainwater tank, summer is when stored water can become particularly valuable.

But a tank is not an unlimited supply.

The combination of rainwater storage + efficient irrigation + mulch + sensible watering practices can make the water you have go considerably further.

It is worth checking your tank before summer too.

Make sure:

• The pump is operating correctly

• Filters are clean

• Irrigation connections are secure

• The tank has been checked and maintained

• Your irrigation system isn't using more water than necessary

If you're planning to rely heavily on stored rainwater, consider how much water your garden actually requires and whether your existing tank and pump are adequate.

The below calculation is based on NZ average household water use, excluding outdoor use:

Read our guide on calculating your water storage requirements HERE

Even smaller urban spaces can benefit from rainwater storage, consider whether this is something you could incorporate before summer

Read our guide on urban water storage HERE

12. Think about what you plant

If you're planning a new garden, summer is a good reminder that plant selection matters.

Some plants naturally require considerably more water than others.

Consider using plants that are well suited to your local climate and conditions, particularly in areas where irrigation will be limited.

You can also group plants according to their water requirements.

There's little point putting a thirsty vegetable garden and drought-tolerant planting on the same irrigation zone if they require completely different watering schedules.

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Dripperline isn't JUST about saving water

Dripperline is often promoted as a way to save water, but its biggest advantage is really control.

You can control:

Where the water goes, When it is applied, How often it is applied & How much water each irrigation zone receives

Instead of standing with a hose trying to decide whether everything has had enough, a properly designed dripperline system can deliver water consistently to the areas that need it.

And when combined with good soil preparation, mulch and sensible watering practices, it becomes part of a much more water-efficient approach to gardening.

Get your garden ready before the heat arrives

You don't need to wait until your garden is drying out to start thinking about summer irrigation.

A few hours of preparation can make a big difference:

• Improve the soil. Add suitable organic matter where needed.

• Mulch the garden beds. Protect the soil surface and help retain moisture.

• Check your plants. Group plants with similar water requirements.

• Install or check your dripline. Make sure it is positioned to water the root zone.

• Check filtration and pressure. Particularly important when using tank or bore water.

• Divide the garden into zones. Different plants have different water requirements.

• Set your timer carefully. Start with a sensible schedule and adjust it according to soil moisture and weather.

• Check the system regularly. Don't wait until a plant is wilting to discover that an emitter is blocked.

• Make the most of stored rainwater. Use your available water where it provides the greatest benefit.

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Need help with garden irrigation?

At WTS we design and install irrigation systems for residential gardens, landscaping and larger commercial and public outdoor spaces throughout the Waikato.

We can help with the complete system — from water storage and pumps through to filtration, irrigation design and installation.

Learn more about our design service HERE

If you're considering installing dripperline, upgrading an existing irrigation system or making better use of your rainwater tank this summer, talk to the WTS team about a system designed for your garden and your water supply.

CONTACT US to chat about your requirements or SHOP ONLINE for Dripperline, irrigation controllers and a range of irrigation supplies.

Dripperline Irrigation FAQs

How long should you run dripperline irrigation?

There is no single run time that suits every garden. The required irrigation time depends on the dripline flow rate, emitter spacing, soil type, plant requirements, weather and system pressure. Start with a sensible schedule, check moisture in the root zone and adjust the duration and frequency as conditions change.

What is the best time of day to run dripperline irrigation?

Early morning is generally a good time to irrigate a garden. Evening can also be suitable. Avoid watering during the hottest part of the day where possible, when evaporation can be higher, although evaporation rates are generally lower with dripperline.

Should dripperline go under mulch?

Dripline can be installed beneath mulch in many garden-bed applications. Position it so the water is delivered effectively into the soil and avoid placing it directly against plant stems or tree trunks.

How far apart should dripperline runs be?

There isn't one spacing that suits every garden. Dripline spacing should take into account the emitter spacing, flow rate, soil type and the plants being irrigated. Closely spaced planting and heavier soils may require a different layout from widely spaced plants or sandy soils.

Do you need a filter for dripperline irrigation?

Filtration is important because the small passages in drip emitters can be susceptible to blockage from sediment and debris. The requirement for filtration and appropriate filter depends on the water source and irrigation system.

Can you use dripperline irrigation with a rainwater tank?

Yes. Dripline can be a good option for irrigating gardens from stored rainwater, provided the pump, filtration, pressure and irrigation system are appropriately sized and configured.

Is dripperline irrigation better than sprinklers?

It depends on what you are watering. Dripperline is particularly useful for garden beds, vegetables, hedges, shrubs and targeted planting, while sprinklers can be more appropriate for lawns and larger open areas. A combination of irrigation methods may be the best solution for some gardens.