Mulching for the Season

During the Growing Season: Temperature and Moisture

During the growing season, then, think of mulch as a moisture and temperature regulator for your soil. Use it to regulate your soil’s moisture and temperature like you use the thickness or absence of a raincoat or winter jacket to regulate your own temperature, except in reverse. No mulch at all and your soil will get hot and dry out, but even the lightest layer of mulch helps your soil stay cooler and retain moisture to an amazing degree. And heavy mulches will keep your soil almost wet and cool in all but the driest conditions.

Different plants like different growing conditions. In general, cool-season plants like cool and quite moist soil, and warm-season plants like warmer and, often, a little drier soil. Mulch each accordingly taking into account the temperature and soil moisture characteristics of each time of the season to create the ideal soil microclimate for each set of plants.

It’s also important to remember that your climate may be quite different than that described above. Perhaps, yours is wetter, leaving you with no need for mulch at all (except to retard weed growth), or hotter and drier, leaving you with a much greater need for mulch earlier in the season. The point is that you use mulch as a tool to create the best microclimates for your plants.

Over the Winter: Temperature

Ideally, garden areas are covered with cover crops during any period they aren’t growing garden plants—and oftentimes at the same time. For some areas of your garden, however, growing cover crops might not be practical. Instead, during those intervening months, cover the soil with a thick blanket of mulch. This thick coat will keep the soil from experiencing the extreme temperature swings and deep freezing characteristic of bare soil. Instead, life will largely go on underneath this protective covering. Earthworms and microbes may slow down or take some pauses, but they’ll remain alive, ready to burst forth come the warmer weather of spring.