What makes the difference between a dense, lush lawn and a sparse, sad one? Often, it’s the lawn feed, and not just what fertiliser you use, but when you use it.
You can feed a lawn regularly throughout the year, but fertilising it in spring and autumn is the most important. In spring, the grass is growing fast and needs all the nutrients it can get. In autumn, the grass gets ready for the harshest conditions of the year, and nutrients can help it winter well.
Read on to find out more about when to feed grass for a healthy and beautiful lawn. We’ll also talk about the earliest and latest month for fertilising every season, as well as when to weed and feed.
When can you feed a lawn?
You can feed your lawn as early as mid to late spring and then continue to feed it throughout the year at regular intervals. Fertilising a lawn in autumn is also important as that helps to prepare it for the cold of winter.
When to feed a lawn is not just a question of the season, climate, or temperature. The best time to feed a lawn also depends on the right conditions. Let’s take a closer look at what these are.
Ideally, the soil should be moist and the grass dry when you apply fertiliser to your lawn. If the soil is dry, it won’t absorb granular fertiliser. If the blades of grass are wet, the fertiliser may burn the lawn.
This doesn’t mean you have to wait for the rain. You can wet your lawn with a garden hose for several days before fertilising it. You’ll also need to water the fertiliser into the soil after applying it.
Tip: If dry soil is a constant problem where you live, consider using a liquid fertiliser.
Rake any leaves, weeds, and debris from your lawn before mowing and applying fertiliser. Pull out any leftover weeds by hand or use a weeding trowel.
If you’re dealing with a serious moss problem, you may have to use a moss killer before feeding your lawn. That said, fertilisers often contain ferrous sulphate which can kill moss within days. So, you may not need a separate moss killer.
Fertilise the lawn right after mowing to give the feed time to work its way into the soil. If you mow soon after fertilising, you may disperse the granular feed and lessen its efficiency.
Once you feed your lawn, wait at least a week before mowing it. This gives the lawn feed time to get to the roots of the grass.
Your lawn needs nitrogen to grow densely. But unless you fertilise it regularly, a lawn often suffers from a nitrogen deficiency. Phosphorous and potassium help to promote lawn growth and keep it healthy during winter.
Nitrogen is the key fertiliser your lawn needs during the growing season. Depending on the quality of your soil, you may also want to add phosphorous and potassium to it. Testing your soil can reveal any deficiencies in phosphorous or potassium.
Check the fertiliser content on the label to know what’s in it. A lawn fertiliser marked as NPK 18-5-10 has 18% nitrogen (N), 5% phosphorous (P), and 10% potassium (K).
Lawn feed may also include:
- Iron sulphate or ferrous sulphate – a moss killer
- Magnesium oxide – helps the grass during winter and supports early growth in spring
- Calcium oxide – increases the amount of nutrients that the soil can hold
Should you weed and feed at the same time?
Weeding and feeding your lawn at the same time is convenient. But it has some major drawbacks.
Weed and feed products can lead to the excessive and uneven application of herbicides to lawn areas where they are not needed. They may kill beneficial fungi and other microorganisms in the soil, compromising the long-term health of your lawn.
What’s more, the synthetic herbicides in these products have been associated with environmental damage and health risks.
Does your lawn have weeds? It’s better to weed your lawn first, give it some time to recover, and then feed it. This approach is also the safest for pets as some weed and feed products may harm them.
When is the best time to feed your lawn?
The best time to feed your lawn is early to mid-spring and early to mid-autumn. With that in mind, you can feed your lawn throughout the year at regular intervals with a break during winter, provided you avoid over-fertilising and pay attention to the weather conditions.
Here’s a quick reference guide to help you to get your lawn feed timing right:
Late March to April
Early June to July
Early to mid-September to October
Spring lawn feeding best practices
Spring feeding your lawn accelerates its growth and makes it look lusher. Mid-spring is often the best time to give your lawn a nutrient boost.
- Don’t apply lawn fertiliser too early in spring as it increases the risk of disease. Wait until you start mowing your grass regularly, that is, until about the third or fourth cut.
- Avoid over-fertilising the lawn in spring as it may damage the grass.
- Spread the lawn feed in two directions or use a mechanical spreader to evenly distribute the granules.
Summer lawn feeding best practices
If your lawn needs it, you can keep fertilising throughout the summer. But granular fertiliser and dry soil don’t mix, so get your hose ready.
- Don’t apply summer fertiliser if the soil is dry as most granular feeds need moisture to work.
- Water the lawn before applying fertiliser if the ground is dry. Wait for the water to permeate the soil.
- Don’t over-fertilise your lawn in summer to compensate for a dry spell as the grass will naturally stop growing. Water your grass and wait for weather conditions to improve.
Autumn lawn feeding best practices
Fertilising your lawn in autumn is important as it will require more nutrients during the dark, cold winter days. Come spring, your lawn will bounce back to life faster and look better.
- Wait for the early autumn rains to soften the soil before applying lawn feed.
- Avoid applying a nitrogen fertiliser late in autumn as it invites disease.
- If it doesn’t rain, water the lawn before applying a granular fertiliser.
- During a dry autumn, apply a liquid fertiliser to reduce the risk of scorching the lawn.
Winter lawn feeding best practices
The low temperatures and frosts of winter plunge your lawn into survival mode. The grass won’t be actively growing so you don’t have to fertilise it. Avoid walking on a frozen lawn as much as possible or you may damage it.
If you do want to fertilise your winter lawn, use the right feed in moderate quantities.
- Use a lawn feed high in potassium and iron and low in nitrogen.
- Apply iron fertiliser in cool and wet conditions to reduce the risk of it blackening the grass.
- Don’t mix iron fertiliser with ferrous sulphate as high iron fertilisers usually include ferrous sulphate.
How often should you weed and feed your lawn?
As a general rule, don’t weed and feed your garden more than twice a year or you may damage it. You may also want to check the instructions that come with the weed and feed fertiliser.
You can apply regular granular fertilisers repeatedly according to the instructions the manufacturer provides. Depending on their concentration, this could mean reapplication every 4 to 6 weeks or longer.
We’ve devoted a whole post to how often you should weed and feed your garden, so check it out.
Is there a best time to fertilise your lawn?
Your lawn needs regular feeding to stay healthy and look its best. But be careful not to overuse fertiliser. Just like your body, your lawn needs food at the right time. Too much can make it sick.
Focus on spring and autumn fertilising and apply lawn feed throughout the year as needed. Follow the instructions that come with the fertiliser as different products may have different application timeframes.
In the end, pay attention to your lawn. It will tell you when it needs a boost of nutrients and when it’s doing just fine.