Advice for your Perth lawn in Summer - by Nick Bell, Advanced Diploma Horticulture-Turf.

When lawns are suffering from heat stress they draw moisture from the leaf. The turf loses turgidity (ie. wilts), the colour turns blue/brown, foot prints are left when the lawn is walked on, and the grass blades are scorched. In most cases however the lawn is not dead and will recover from stolons and rhizomes which are underground after adequate watering.

From the beginning of December until the end of February hand-watering or watering with portable above-ground sprinklers is often needed to supplement Water Corporation allocations.

But the first thing to do is to do a test on how efficient your sprinkler system is. You may be able to adjust it, or fix the system to bring your lawn back to health once you know how much water it is receiving - you might be surprised by the results.

Testing your retic - how much water is your lawn getting?

Catch cups (graduated measuring containers) are a valuable tool in testing how efficiently a sprinkler system is operating.

Calculate the run time required to deliver a standard drink by testing how efficiently the sprinklers are operating. Spread catch cups randomly around the watering zone. Make sure they are at least 1 metre from the closest sprinkler. Note how long it takes the sprinklers to fill the catch cups to the depth required. For example, on a sandy soil a standard drink is 10mm of precipitation so the average depth of water in each catch cup needs to be 10mm. If there is a larger variation in the depth of water captured by the various catch cups then the sprinkler system is not applying the water evenly and should be checked for design or maintenance faults. Once the faults have been corrected run the test again to determine how long to run the sprinklers to deliver the standard drink.

The following Catch Cup DIY Test will enable people to determine the amount of water applied with sprinklers.

1. Place straight sided coffee mugs midway between sprinklers.
2. Run irrigation system for 10 minutes and use a ruler to measure and record the water in mm collected in each mug.
3. Divide the total amount of mm collected by the number of catch cups (mugs).
4. Repair or if necessary replace broken or malfunctioning nozzles or sprinklers.
5. Adjust the run time on each station to ensure that an average of 10mm of water is collected on each of the allocated watering days.