Spring is prime feeding season for SEQ lawns and gardens. As soil temperatures climb and warm-season grasses like buffalo, couch and kikuyu come out of their winter slowdown, they're ready to take up nutrients again – and a spring feed sets up months of strong, healthy growth.
It's also the time of year we see the most fertiliser burn. Scorched patches on a lawn, or crispy brown leaf edges on garden shrubs, are almost always down to how the fertiliser was applied rather than the product itself. The good news is burn is easy to avoid once you know what causes it.
What fertiliser burn actually looks like
Fertiliser burn happens when concentrated nutrients and salts sit against leaf or root tissue and draw moisture out of the plant. It shows up as yellow or brown patches, often in stripes or blotches that follow the application pattern, usually within a few days of feeding. On lawns it can look a lot like a dry patch or disease at first glance – the giveaway is that it tracks the shape of how the fertiliser was spread.
How to avoid it
Water beforehand
Apply fertiliser to a lawn or garden bed that's already moist, not bone dry. Dry soil and stressed plants are far more prone to burning, since there's less moisture to buffer the concentrated nutrients.
Water it in afterwards
A thorough watering-in straight after application washes granules off the leaf surface and down into the soil, where the roots can use them safely.
Spread evenly
Overlapping passes with a spreader are one of the most common causes of burn, since they double up the dose in a strip. A calibrated spreader and a steady, even walking pattern makes a real difference.
Skip the extreme heat days
Avoid applying on days forecast over the mid-30s, or during the heat of the day. Early morning or late afternoon, when it's cooler, gives the fertiliser time to work in before the sun is at its strongest.
Follow the rate on the bag
More is not better – over-application is the single biggest cause of burn we see. If in doubt, a slightly lighter application is always safer than a heavy one.
Choose slow or controlled-release where you can
These products feed steadily over several weeks rather than delivering everything at once, which spreads the nutrient load and lowers the risk of burn considerably. They're worth the small extra cost, especially on lawns.
If it's already happened
If you've spotted burn, there's no way to undo the damage to the affected tissue – but a few things stop it getting worse and support recovery:
- Water heavily and immediately. A thorough soak helps flush excess salts out of the root zone before they cause further damage.
- Give it time. Mild burn on a lawn often grows out as new growth comes through over the following weeks.
- Repair severe patches. Badly burned lawn areas sometimes need overseeding or turf repair rather than recovering on their own.
A note on Moreton Bay conditions
Our sandy soils in parts of the region drain quickly, so nutrients can wash through before plants get the benefit – another reason slow-release products work well here. If spring brings a wet stretch, hold off feeding until the ground has firmed up a little; fertilising into waterlogged soil doesn't just risk burn, it's largely wasted product.