Why did fertiliser burn my lawn?

Fertiliser contains salts. In the right amount, spread evenly and watered in, they’re simply nutrients. Concentrated in one spot, they draw moisture out of grass leaves and roots, and the grass scorches. That’s fertiliser burn.

The pattern of the damage usually tells you what happened:

• Stripes in the direction you walked mean overlapping passes or a spreader set too wide open.
• Spots or blotches mean spills: filling the spreader on the lawn, a bag tipping over, or stopping without closing the spreader.
• General scorching after feeding on a hot day means granules sat on the leaves, especially wet leaves, before being watered in, or the rate was too high overall.

Fixing it

Water the area deeply for a few days to dilute the fertiliser and move it below the root zone. Scoop up any visible piles first. Most warm-season lawns recover from runners at the edge of the damage once the excess is gone, though badly burnt areas may need patching.

Preventing it

Measure the lawn, calibrate the spreader for the product you’re using, apply at the label rate in cooler weather, fill the spreader over a tarp or hard surface (then sweep up), and water in as the label says.

Is it burn or something else?

Burn appears within days of feeding and follows the pattern of how you spread. Brown patches that appear weeks later, keep spreading, or show no pattern are more likely to be dry soil, lawn grubs or disease. Check those before blaming the fertiliser.