Mulching is feeding and it’s one of the most beneficial things that you can do for your lawn (and gardens too, we’ll cover gardens later). Lawngrass roots soak up moisture and nutrients for growth. The moisture is easy to replace by watering, but the nutrients are either native to the soil or provided by fertilizer. If you rake or bag up your lawn clippings, these nutrients are lost. Mulch them back into the lawn and the nutrients are recycled.
It’s estimated that mulching can reduce your need for feeding up to 30%. And it’s easy to do, probably a lot easier than raking or bagging. Grass clippings work their way down to the soil layer where, with adequate moisture, they are quickly reduced to mulch by native bacteria and fungi. If you’re lucky enough to have a healthy earthworm population, they’ll help spread the remaining mulch throughout your topsoil layers. This is a double plus as the mixed in mulch will loosen hard caked soils and help retain water.
Earthworms are present in just about any healthy lawn or garden area that hasn’t been treated with harsh chemicals. Although most pesticides don’t outright kill earthworms, many can decrease the population as they reduce general health and reproduction. High nitrogen fertilizers fall into the same category, which is why I recommend half strength fertilizer applications and avoiding most lawn treatment companies.
Most power mowers have mulcher attachments. These usually include special chopper blades and plates that cover the discharge chute. Grass clippings are chewed up to small pieces that easily sift down to the lower levels of the grass.
Some may confuse mulched grass with thatch. Thatch is when the living parts of grass plants build up too thick. Then these extra stems, roots, and leaves weave themselves into a mat that blocks our air, water, and nutrients. Thatch doesn’t break down as it’s still alive. Mulch is dead and will break down easily.
When not to mulch:
There are a few situations where mulching may not be beneficial. If your lawn is diseased, it’s best to rake up and dispose of the clippings to prevent the spread of the disease. The same after fungicide applications. Mulching after fungicide application may not only spread the fungus, but the fungicide might prevent clippings from composting to mulch.
It’s also difficult to mulch lawn clippings when it’s cut wet or heavily overgrown. Mulched grass clippings tend to stick together in clumps and look terrible. If too thick, these clumps can block out sun and water from the grass below. If you have a lot of these clumps, try letting them dry for a while and then running the mower over them again. It’s time to get out the rake or bagger if that doesn’t work. Then, as long as you haven’t used weed killer or harsh chemicals, use it to mulch your gardens.