Most professionals and consumers agree that organic mulch should be considered first over inorganic mulch.  There are many articles arguing why, and they cite reasons such as biodegradation, aesthetics, environmental considerations, and design features.  Among these arguments, and one that is rarely considered, is the nutritional benefit organic mulches provide your plants, and the soil as a whole.

This article focuses specifically on hemp, a relatively new material to be used as mulch in the United States, but one that is quickly gaining preference for its absorption and adsorption abilities, aesthetics, and environmentally friendly growing methods.  And as you’ll see here, it’s a great way to get your plants off to a healthy start.

I need to mention that this nutrient analysis was done using a specific type of industrial hemp, grown in a certain part of the world.  As with any all-natural fiber, you should consider these numbers part of a range.

The hemp used for mulching is grown using no herbicides or insecticides, as none are needed.  Only organic fertilizer is used.  Once harvested, this hemp was field retted for a specific period of time.  The retting time is chosen purposely to accentuate the benefits of hemp as a mulch.

Hemp nutrients:

All Dry Weight basis

Total Nitrogen (%) 0.46
Phosphorus (mg/kg)             470
as P2O5 0.11
as K2O 0.9
Potassium (mg/kg) 7500
C/N ratio 89.1
pH 7.23

A pH of 7 is considered neutral.  Less than 7 is considered acidic, and greater than 7 is alkaline, or basic.

Nitrogen (N) is beneficial to leafy plants.  Phosphorus (P), is necessary for good root development, and for fruit and vegetable growth.  Potassium (K) is needed for overall plant functions, and provides for healthy growth.

You might find you need a fertilizer supplement to your hemp mulch, depending on the type of plants in your garden application.  We always recommend a natural, organic fertilizer.  But compared with most organic mulches, hemp provides a benefit right out of the package, without pulling nitrogen from the soil.