Back to Gardening Chapter 2 Part C: The Organic Mulch Approach to Gardening - Types of Mulch

In this part of Chapter 2, I compare different sources of organic mulch in terms of their speed of decomposition, moisture retention, nitrogen content and their capacity to control weeds.

Chapter 2: The Organic Mulch Approach to Gardening

C. Types of mulch

There are two types of mulch: inorganic and organic. The former is comprised of substances that do not break down, whereas the latter does break down.

A good mulch can make a big difference in a garden, but there are so many options!

I) Inorganic mulch

Inorganic mulches are things like black plastic, landscaping fabric and other synthetic materials, and even things like rocks, pebbles and sand. Inorganic mulches can provide excellent moisture retention, weed prevention, and they also can last a long time because they do not break down (or in the case of some synthetics, break down very very slowly). Since this chapter is entitled “The Organic Mulch Approach to Gardening”, it follows that I do not intend to engage in any sort of lengthy discussion about inorganic mulches - but I do think they have their place. For permanent pathways they are ideal, since they do not need to be replaced and improving soil health in pathways doesn’t matter so much. Likewise, for some perennial gardens I think they are ok - so long as the plants are monitored and the soil is amended in some way whenever the plants seems to be in need of nutrients. I make this distinction because perennials have large root systems that get larger each year - so they tend to be good at finding nutrients anyway. The perennial herb garden in my driveway (rosemary, oregano, thyme, tarragon, savory, & sage) has been mulched with sand for almost a decade. I’ve never watered them in all that time. The herbs come back bigger and better each year, and all I do is give them one does of compost tea each year - and I’m not even sure if they need it!

II) Organic mulch

Organic mulches provide all the benefits of inorganic mulches, but they also break down and become compost over time, and by virtue of that process, as explained in the previous part of this chapter, they help maintain and improve soil quality. There are many types of organic mulch, all with their pros and cons - so I though it would make sense to organize them in a table with simple ratings that speak to their various properties.