Green Up Lawn Food, what it is and when to use it

March 24, 2025

Green Up Lawn Food, what it is and when to use it

Green Up is a granular lawn food, so it's a dry prill you spread over the grass and water in, and what it's mostly doing is putting nitrogen down. Nitrogen is what makes a lawn green and makes it grow leaf, which is the whole point of a lawn, so a lawn fertiliser is built differently from a garden one on purpose.

Watering it in is not optional

If you take one thing from this, take this one. Granular fertiliser sitting on dry grass in the sun will burn the lawn, and the burn shows up as yellow or brown streaks exactly where you walked with the spreader. It is the commonest lawn fertiliser disaster there is and it is completely avoidable.

Water it in properly straight after you spread it, and give it a real soak rather than a rinse. Put it on in the cool of the morning or the evening rather than the middle of a hot day, and don't put it on a lawn that's already dry and struggling, because a stressed lawn takes the knock much harder than a healthy one. Water a dry lawn first, wait a day, then feed it.

Getting the rate right

Work off the rate on the bag, which is given in grams per square metre, so measure your lawn once and write the number down somewhere. Everyone guesses and everyone guesses high.
Use a spreader if you've got one. Throwing it by hand is how you get a striped lawn, because the heavy bits land near you and the light bits carry.
Go over the lawn in two passes at half rate, walking at right angles the second time. It evens out anything you missed.
Sweep any prills off the path and the driveway before you water, otherwise they wash straight into the stormwater and end up in the creek.
Keep the dog and the kids off until it's watered in and dry.

More nitrogen is not a better lawn

Feeding harder and more often does not get you a better result, and past a point it gets you a worse one. A lawn pushed hard on nitrogen grows soft, sappy leaf that needs mowing constantly and wants more water than it did before. It is also more susceptible to some of the fungal problems rather than less, and it grows leaf at the expense of root, which is the opposite of what you want going into a dry summer.

Potassium is the one that helps a lawn handle heat and dry, so if your lawn greens up beautifully and then falls over every January, a potash application is a more useful thing to add than more nitrogen.

When to feed

Feed while the grass is actively growing, which for the warm season lawns most people have here means the warmer months, and taper off as it slows down. Feeding a dormant lawn in the middle of winter mostly feeds the weeds, since they're the ones still growing.

Timing on a lawn food is a judgement about your own grass rather than a date on a calendar. If it's growing and you're mowing it, it can use a feed. If it's sitting still, it can't.

Shop related products

Brunnings Green Up Lawn Food 5kg. The granular lawn food this post is about.
Brunnings Green Up Lawn Food 2.5kg. The smaller bag for a small lawn or a first go.
Brunnings Potash Power 2.5kg. Potassium, for a lawn that greens up and then struggles in the heat.
Brunnings Tough Lawn Seed 1kg. For patching the bare spots once the rest is growing again.

Did you know we also stock Green Up in the 10kg and 20kg bags, along with spreaders, in the shop. They're not all on the website, so give us a ring on (08) 8536 4333 to check what's on the shelf.

The rest of the lawn gear is in our garden centre and the wider garden range is online. A 20kg bag is a fair lift, so we deliver Tuesdays and Thursdays on anything bought from us, $5 around Strathalbyn and $10 on the regional run. Local delivery.

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Green Up Lawn Food, what it is and when to use it