How often should you fertilize your lawn and when?

If you’ve ever wondered how often should you fertilize your lawn, you’re not alone. In fact, many avid gardeners and landscapers wonder about this question: how much is too much and is it possible to over-fertilize your lawn? Although fertilizer contains many beneficial nutrients for your lawn, applying too much can actually do more harm than good. Not to mention that this habit can be expensive. But, apply too little and your weed won’t have the best chance of growing, so it’s important to strike a balance between the two.

Here we’ll cover how often you should apply fertilizer as well as when to get the best results. We’ll look at the consequences of overuse, as well as the best method of application. This means you can rest assured that your weed is getting exactly what it needs to thrive. So how often should you fertilize your lawn? Here is the answer.

How often should you fertilize your lawn?

Advice varies widely on this, as you may have seen before. The exact answer will depend on the type of fertilizer you use – a slow release fertilizer will last longer and require fewer applications. However, a typical synthetic fertilizer will act quickly, but require more frequent applications.

Most recommend a minimum of two applications per year if you’re using a slow-release fertilizer, but that’s not set in stone – some experts recommend up to 4-5 annual applications. If you’re using a fertilizer that doesn’t last as long, you may need to apply it much more regularly to keep up the looks. The right answer for you will ultimately depend on the soil levels of your lawn as well as the fertilizer you choose.

A man pushing a spreader and distributing fertilizer

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Ian Grant, lawn care expert at National greenhouse (opens in a new tab) advises: “We suggest treating your lawn 4-5 times a year. Being the end of summer, your treatment should contain plenty of iron to keep the grass deep green and this helps the roots grow to enjoy maximum late summer sun. This late summer treatment is especially useful if your garden is heavily worn by children or pets.”

When should you fertilize your lawn?

While late summer is indeed a great time to fertilize, the best time to apply your fertilizer will also vary depending on the type of grass you have. According spruce (opens in a new tab), if using a slow-release fertilizer and applying it twice a year: Cool-season grasses, often found in the Northern Territory and including Kentucky bluegrass, should be fertilized at the late spring, then again in early fall. While warm season grasses, found in the south, such as Bermuda grass, should be fertilized six weeks after the last spring frost and again at the end of summer.

If you want to apply your fertilizer more regularly, depending on Scott (opens in a new tab), the best practice is to feed the grass in early and late spring, as well as summer and fall. So your first meal would be between February and April, followed by April and June, then June and August, and finally August and November. Try to leave 6-8 weeks between each application and perform a soil test regularly to keep an eye on conditions. We recommend the rapidest Luster Leaf soil test kit ($13.17, Amazon (opens in a new tab)). Make necessary changes to your fertilizer and application based on these results.

A soil test giving a reading in the soil

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When it comes time to fertilize your lawn, make sure you pick the right time of day to do it. Ideally, you want to apply your fertilizer either early in the morning or late afternoon/early evening. This is because you don’t want the heat and sun to burn the grass during the peak hours of the day. You also want the grass to be moist rather than wet, otherwise the fertilizer can stick to the blades of grass. Keep in mind that once applied, the lawn will need to be watered shortly afterwards, either by yourself or by the weather. Follow the instructions for how long to wait before watering.

What happens if you over-fertilize your lawn?

Whatever you do, don’t hesitate to roll up and fertilize your lawn just because you can. When using synthetic fertilizers, over-fertilizing can actually do more damage than not fertilizing at all. Greensphere (opens in a new tab) explains that too much fertilizer will cause a growth spurt that your lawn’s root system simply can’t keep up with – this means your grass will struggle to absorb the water and nutrients it needs.

Over-fertilizing will also increase nitrogen and salt levels in the soil to the point of killing grass. The result is yellowing patches of dead grass on your lawn, aka fertilizer burn. If you’re guilty of over-fertilizing and the damage is already done, you’ll need to give your lawn time to recover to soil levels. But, there are steps you can take to get things done.

Lawn with a patch of brown dead grass from too much fertilizer

(Image credit: Shutterstock)

According spruce (opens in a new tab), you must first remove any excess fertilizer as soon as possible and distribute what remains on your lawn. Then saturate your garden with water to dilute it – apply about an inch a day for a week, or until you see your grass recovering. Any areas of dead grass will also need to be reseeded once the ground has returned to level – you can use a soil test kit to monitor its progress during this time. Check out our guide to how to plant grass seeds for more details on this.

To avoid over-fertilizing, the best advice is to simply follow the dosage instructions given on your chosen fertilizer and distribute it evenly when applying using a spreader. Scott (opens in a new tab) recommends starting at the perimeter and then working through the center the same way you would with a lawn mower – that way you won’t miss any areas. Also make sure your lawn has been watered a few days before application. If you do this, the soil will absorb the fertilizer better.


For more lawn tips, tricks and advice, check out our guides on how to plant grass seed, how to make your lawn greener, how to scratch your lawn, how to lay sod, 7 common lawn mistakes. lawn care you are probably. do right now and 7 ways to revive dead grass.

While you’re working in the garden, you might want to check out our guide to the best gardening gloves we’ve tried and tested.


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