In the book, The Holistic Orchard, Michael Phillips is a commercial organic fruit grower that has gone sustainable in recent years. He also uses ramial wood chips. Hear me out! I know this is controversial. Read the description of ramial wood chips at the link below, because they are not just any wood chip that can potentially rob soil of nitrogen.
Ramial wood chips, from Wikipedia: “[They are a] relatively high ratio of cambium to cellulose compared to other chipped wood products. Thus, it is higher in nutrients and is an effective promoter of the growth of soil fungi and of soil-building in general. The goal is to develop an airy and spongy soil that holds an ideal amount of water and resists evaporation and compaction, while containing a long-term source of fertility. It can effectively serve as a panacea for depleted and eroded soils.”
So, the idea being, building a spongy soil. We all know that compacted soil is the death of plants. Roots need to breathe every bit as much as leaves.
This video, from one of my favorite Youtube producers (good ol’ John), shows wood chips used in gardening (not necessarily ramial wood chips either).
We have to walk under and around fruit trees. Their roots extend beyond the drip line. Think of it this way: when we’re in an ancient forest, there is all manner of broken limbs, twigs, leaves, and needles that we walk across, without compacting the soil. Over time, these decay and cause this spongy soil that never compacts. It provides fertile ground and aerated soil for new seeds to germinate and grow. No one ever cleans away this decaying debris.
Now think of urban trees. All leaves and debris are cleaned away. Generally, one type of tree is planted in entire neighborhoods sidewalk strips, which is like a neon sign to the one particular pest that invades them.
Chips also retain large amounts of water, rather than letting it roll away and cause flooding. They also keep water from evaporating. Bare soil equals rapid evaporation, requiring more watering. Chips keeping soil moist means less watering. No one is in a forest to water the trees, yet they grow and thrive without human intervention.
Wood chips are typically used only on top of the soil, not mixed in the soil, when one wants to promote a fungal environment in the soil. But having said that, an experiment I did with my marigolds was to clear away the wood chips, expose the soil, put the roots on top of the soil and surround the root ball with wood chips. It worked like a charm! They grew beautifully.
Back to fungal soil. Fungi serve important functions. They take up the sugars that plants produce, and in turn supply nutrients, especially phosphorus that is so important to ward off pests, the plants need. This becomes a symbiotic relationship.
The phosphorus that fungi produce causes plant growth 10 times over the growth without phosphorus, and improves seedling survival. Fungi produce a large underground network that connects plants. In turn, this encourages good soil structure, making it easier for nutrients, water and air exchange within the plant root zones. Fungi breaks down compounds in soil that prevent nutrient uptake in plants. In fact, there are so many benefits to fungi, it’s a vast subject that one could write a book. For more on this subject, refer to MYCORRHIZAL ASSOCIATIONS.
Over 80% of fungi are associated with trees. Due to this, ramial wood chips are especially suited to being placed around the root zone of trees. It need not be consistently, or solidly, placed. It should be spaced relatively sporadic, to mimic a forest floor. Personally, I use wood chips in our garden for weed suppression. We use it on our paths and beds.