September 24, 2025, 8:30 am | Read time: 3 minutes
As the days get shorter and the nights cooler, it’s high time to prepare the lawn for the winter months. But what really matters in this process? Which care steps are crucial–and what should be avoided? myHOMEBOOK consulted a professional to explain what garden owners should consider now to make their lawns winter-ready.
Start Early–Already in Summer
“The best preparation starts in the summer,” explains Dr. Nonn from the German Lawn Society in response to a myHOMEBOOK inquiry. Grasses need sufficient leaf mass to build up enough reserves through photosynthesis. “Only in this way can they form roots, leaves, and enough reserves for the non-growing season,” the expert explains.
Those who pay attention early on also promote a healthy, dense, and visually appealing lawn. The cutting height is crucial. For home lawns, Dr. Nonn recommends a height of about 3.5 to 4.5 centimeters to keep the leaf mass stable.
The Right Fall Fertilization
Targeted fertilization is also part of optimal preparation in the fall to make the lawn winter-ready. “I recommend fertilizing with a potassium-rich product starting in September,” says the expert. Potassium helps grasses better cope with frost, strengthens cell structure, and supports the storage of reserves in leaf sheaths and roots.
“In the fertilizer analysis, you can recognize the potassium content by the third number in the analysis (N-P-K),” explains Dr. Nonn. N stands for nitrogen, P for phosphorus, and K for potassium. When purchasing, you should specifically look for products labeled as “potassium-rich” or “fall fertilizer.”
When Should You Mow the Lawn for the Last Time?
The lawn cutting remains a topic in the fall. When asked when to mow for the last time, the lawn expert has a simple answer: “Mow as long as there’s something to mow.” As long as the grass grows, it can be cut. The recommended cutting height of 3.5 to 4.5 centimeters should definitely be maintained. “There is no agronomic necessity to mow deeper or higher,” Dr. Nonn clarifies.
What Your Lawn Absolutely Needs in September
How to care for your lawn in December
Where to Put the Leaves on the Lawn?
An often underestimated measure concerns the falling leaves. “Leaving the leaves on the lawn is not a good choice,” warns Dr. Nonn. The reason: “Fungal diseases develop under the leaves, causing grasses to yellow and die.” Instead, the leaves can be used effectively—for example, as mulch material in beds or as shelter for hedgehogs and insects. If there’s no use for them, the expert recommends disposing of them in the organic waste bin.
Don’t Forget: Check the Lawn Mower Before Winter
Not only the lawn itself, but also the lawn mower needs some care before winter. According to Dr. Nonn, you should clean the device and sharpen the blades—or have them professionally sharpened. Depending on the model, it is also advisable to charge the battery, change the oil, and check the spark plug.