How to calibrate your lawn fertiliser spreader
Applying fertiliser is a daunting thought for some lawn owners but you can sleep at night, and not worry that you will wake and find rust orange burnt patches, by making sure that you have calibrated your fertiliser spreader before tackling the task.
It is not sufficient to simply 'bucket and chuck it', a reference I heard today from a maintenance gardener!
Don't be put off by the word 'calibration', it may sound scientific, but actually it is as easy as pie if you follow our simple guide.
The easy way to calibrate any spreader is to set the spreader on the desired setting, pour some product in the hopper, protect your drive with plastic or a tarpaulin, position a sheet of clean polythene one metre square onto the driveway (not the lawn!) then walk over the polythene, with the hopper gate open so the fertiliser is flowing and being spun on the spinning disc or dropping from beneath the spreader, make two passes if the polythene has not been evenly covered with fertiliser by only one pass of the spreader and then collect up the material on the polythene and weigh it making sure that you place a small plastic bag into the scales first.
You are looking for 30 grams per single square metre ie.e that covered the plastic, if you have then you are doing it right! You may need to repeat the process a couple of times.
If you are only getting 15 grams then fertilise the lawn in two passes, the second at right angles to the first so as to provide sufficient fertiliser and even coverage. The majority of lawn fertiliser scorch problems occur mainly through the effect of the Iron content of lawn fertilisers as it is often the iron that causes the scorch burn - this is why we protect the drive because the iron will cause unsightly rust marks on concrete or tarmac surfaces.
Make sure that you are not standing still on the lawn with the hopper gate open pondering about how to transverse over the lawn area and also that you are actually moving BEFORE you open the hopper trigger so as to avoid a dump on the lawn. Make the first pass around the edges of the lawn first - called a headland, then work up and down being careful to match in the fertiliser swaths. The products may be part coloured so after a little practice, you should become good at it!
Another tip is to mow the lawn first and then follow your mowing lines. Walk at your normal walking pace and if you know the size of your lawn and can easily calculate that you have not applied enough then go over the lawn again at right angles as described above.