How To Calibrate a Broadcast Spreader

When it comes to calibrating your spreader it can be a daunting task if you are unsure on how to do it. If you get it wrong you could end up either spreading not enough or too much over the lawn which, with both fertiliser and grass seed, it is essential that you get an even layer over the entire lawn. As it is such an important thing to get right, we thought we would put together an easy step-by-step guide to making sure the job is done right each time.

What equipment will I need?

You will need:

• Broadcast spreader
• Large jug or bowl
• Scales
• Either fertiliser or grass seed
• Marker sticks or flags
• Pencil
• Tape measure (ideally 20-50m tape)

Step-by-step guide to calibrating a broadcast spreader

1. Using your tape measure, measure out a 20m length and mark both ends with the marker sticks/flags.
2. Cover the area that you are doing tests on with a tarpaulin so that you can easily see results and you have not wasted any product during your tests.
   
3. Put your fertiliser/grass seed into a jug and weigh it on the set of scales, noting how much you have in grams.
   
4. Pour the fertiliser/grass seed into the spreader making sure that the handle is in the shut position so it doesn’t just fall through.
   
5. Choose a setting on your spreader (ideally you should do tests on the lowest, mid-range and highest settings so you can get an idea on the different spreading rates).
   
6. Starting a little way back from the first marker, walk towards the second marker at a comfortable walking speed, opening the handle and beginning to spread the fertiliser/grass seed.
   
7.  Using the tape measure, measure the width of the product spread. As this step has been done on a sheet/tarpaulin it will be easy to see exactly where it has got up to.
   
8. Empty any product left in the spreader into the jug and weigh the remains. The difference in weight from the amount of fertiliser/grass seed you had in the beginning and the amount you have left over, is the amount of product you have used.
   
9. Once all these steps have been followed, you will then need to complete the following calculations to work out the amount of product needed per metres squared for that specific spreader setting: