Can You Use Mulching Lawn Mower Blades Year-Round?

A healthy lawn depends on healthy soil, sharp mower blades, and proper nutrients. Regarding the efficiency of mowing, few debates generate as many opinions as mulching versus mower blades and whether to bag or mulch your clippings. Mulching blades are a popular choice for lawn mowers because they are designed to chop grass clippings into small, nutrient-rich pieces that fertilize your lawn. But what about leaving them on your mower from one season to the next? Can you use mulching lawn mower blades year-round? The short answer is yes, but the trick to keeping your yard lush and clump-free in every season is knowing when to let them shred and when to switch strategies.

If you do leave the mulching blades on throughout the year, there are a few rules to maintain a healthy lawn and prevent any problems with the mower itself. Firstly, never remove more than one third of the grass blade height at a time. Passing mulching blades through thick and long grass will cause stress to the engine of the mower and result in clumped grass clippings. It is also important to keep the blades sharp, since mulching blades depend on the precise curves of the blades for their ability to lift and cut the grass several times.

Spring's rapid growth and high moisture mean bagging early or after rain prevents clumping, though you can mulch once grass dries and growth slows. Summer is prime mulching season — clippings return moisture and nitrogen to heat-stressed turf. Autumn lets you shred light leaf cover into nutrient-dense mulch, meaning you'll only need to bag thick, wet mats. When winter brings dormancy, take advantage of the downtime to easily sharpen your lawn mower's mulching blades or replace them for next season.

The advantages that come from keeping the mulching blades on your lawn mower all year include convenience and good soil quality, but there are some downsides depending on the season. Deciding to keep mulching blades on full-time is a lawn mower swap that cuts better for a healthier yard, saving you from having to change blades back and forth when seasons transition. You could even install a grass catcher bag or a side discharge chute with the mulching blades already attached when your grass becomes longer. It will not only be convenient for you but also good for the lawn. By returning the trimmings from your lawn to the soil where they decompose, you continuously recycle nitrogen, potassium, and phosphorus to the soil without the need to add fertilizers.

However, mulching blades are likely to struggle during periods of rapid growth in spring or in wet grass after the rains, leaving you with large clumps in your yard that will have to be raked up in order to ensure the grass's good health. Also, finely shredded wet grass has a tendency to stick to the bottom of the mower deck and create a dense accumulation that hampers airflow and leads to rusting of steel decks if not cleaned periodically. Last but not least, the state of your lawn should be taken into account. If your lawn suffers from fungus or goes to seed in late spring, mulching will spread the spores or seed all over the yard, potentially impacting the whole lawn. You'll need to make sure you attach a grass catcher bag to contain the debris and prevent disease or weed seeds from spreading.