Spring Mulch on Site aka Chop and Drop Mulching

It’s important to consider our unique Mediterranean climate this particular time of year. Getting a basic understanding of how our seasons, the hydrologic cycle and your gardens all interact is not only fascinating but essential for healthy plants and soil life.

chop and drop wheat and other grasses for green mulch

 

Precipitation exceeds evaporation in the Spring*.  Air and soil temperatures gradually rise with increasing daylight hours, critters become more active, plants begin to grow again and everyone thrives with the moisture and additional warmth of early Spring.  How we can utilize this seasonal activity to our benefit and ultimately the health of the whole landscape? 

Mulch-on-Site 
aka Chop and Drop mulching

‘Chop and drop’ means chopping down and dropping to the ground green mulch –literally where you stand or collected in piles for use in other locations.  Basically you’re harvesting living mulch rather than buying in straw or bark.  We use a rice knife (pictured below) rather than a 'weed eater' or string trimmer (reduced fossil fuel consumption) to chop and drop early spring grasses before they flower as well as other plants some consider weeds.  Some plants die back for good, others, like perennial grasses, are smothered and are eventually out-competed by preferred mulch plants.

A rice knife -best chop and drop tool around

Growing specific plants to produce mulch for the garden serves many purposes; first and foremost is the cheap and freely available mulch needed by all healthy plants and soil life.  Second are the specific types of plants you grow which add certain nutrients to the soil.  This addition of micronutrients (as well as macros) cuts back the need for out sourced organic fertilizers.  Build the soil’s food web in a diverse way (by the addition of dynamic accumulator and nitrogen fixing plants for starters) and you have healthy plants in an evolving ecosystem.  When your plants are chopped back the roots die off somewhat too leaving an abundance of organic matter under the soil further increasing organic content thus microbial food… thus readily available plant nutrients over time.

This seasonal method of mulching on site provides an organic matter layer to the top soil which substantially reduces soil evaporation later in the season.  Try this chop and drop method in the middle of summer, after evaporation exceeds precipitation, and the results are not the same.  Fungi, bacteria, protozoa, arthropods and more all rely on moisture and diverse foods to grow and reproduce, which these early additions of mulch supply.  When the air temperatures are high (evaporation is directly related to temperature) green mulches dry out before soil organisms can break them down and make them useful to your plants.

Spring is also a good time of year to trim back any old growth on perennial plants you left standing for overwintering beneficial insects. Before everyone wakes up too much you can trim them back which will increase available light as well as add valuable brown mulch to the beds.  Just make sure you leave the mulch trimmings around the plant you pruned so if the frost hits hard again they have a ‘blankey’ of mulch to keep warm.  

For more information on Mulch on Site techniques to reduce if not eliminate outside mulch inputs to your garden, check out our Mulch on Site pages.  Mulch on Site and What is Mulch on Site?

* Precipitation exceeds evaporation starting late Fall through early Spring in our climate but until March we are dominated by the cold, dark time of year.