There are a couple of important things I want to share about how to use mulch in your organic garden.
When we were kids we would help our aunt and uncle put their vegetable garden to rest for the winter, using leaves for mulch.
We’d collect them into a pile, jump into them and play a while, mow over them with the lawnmower, then pile the mulched pieces onto the soil.
We would use a pitch fork or a hard rake to turn them into the top couple inches of soil.
Our aunt had a huge property with many different trees so this garden mulch became a layer of stunning rainbow colors.
Fast forward years later. When we started doing my own landscaping I would spend big bucks on yards and yards of cedar mulch and lay it several inches thick over the soil.
I thought it was the perfect finish to a garden because it helped control weeds, retained moisture and looked good. But I was always wondering, what kind of mulch should I use? Is cedar mulch really the best?
After I got into organic gardening I learned that my aunt 15 years earlier had a better understanding of how to use mulch in landscaping.
The best way of using mulch depends on which plants are in the garden, so let’s look first at a few general principles:
1) When we use mulch on the soil surface, particularly woody mulches, we’re promoting more fungal growth.
2) When we incorporate mulch into the soil, we promote more bacterial growth.
3) If we till the mulch into our gardens, we cut the fungi hyphae all to pieces, resulting in a highly bacterial-dominated soil.
I’ve written about what mulch to use before, but here I want to look at how the above 3 points impact how to use mulch with certain types of plants…
Trees, shrubs and most other perennials
These generally need a fungal-dominated soil, so if we’re trying to establish an orchard, or a few shade trees, or a shrub garden, definitely leave the mulch on the surface.
Also, this is a time when it’s okay to use some wood chips in your mulch because they promote fungi. Using leaves as mulch is still always an important part of it, but some wood chips in there will be beneficial.
The important caveat is that if it’s deciduous trees you’re planting, use wood chips from deciduous trees. If you’re planting conifers, use conifer chips. Using mulch of coniferous chips on deciduous trees, for example, promotes the wrong kind of fungi, and causes other incompatibility issues, too.
And either way, bark mulch isn’t good because it contains toxins. And to repeat, leaves are the ultimate, sustainable, awesome mulch.
Vegetables and annuals
These prefer more of an equal balance of bacterial and fungal mass, so we don’t use wood chips, and we may even turn the organic matter into the top inch of soil.
Or we may not, as we still try not to disturb the soil too much in the long run. But we’re definitely not going for a thick, woody mulch.
So however you use mulch in the garden, always remember the best mulch is what you would find in nature. In a forest, it’s mostly leaves with some woody debris in there. We take a clue from that for our trees and shrubs
When annual plants are pioneering new ground in nature, the bacteria will be the major players, and it’s mostly leafy and herbaceous debris, so that’s what our vegetable garden looks like.
If it comes from the garden center and is dyed purple or neon green, it’s probably not something you want in your soil!
What do you think? Have your mulching practices changed since you got into organic gardening? Any other questions about how to use mulch? Post down below.