Ramial chipped wood is different from arborist wood chips or other forms of wood chips. Unlike arborist’s chips, ramial chips are taken from slender green branches, usually less than 7 cm or ¼ inch in diameter. Ramial chipped wood can include organic matter like green leaves along with these young green shoots.
But why would someone use this wood? It’s actually pretty simple: the young, green shoots on most trees are the most nutrient-dense portion of the tree. The tree will be fueling its growth, and as a result, that’s where the best chips come from. If someone’s doing light pruning of their trees, turning those pruned shoots into chips will provide the best chips for fungal development.
Since fungi form a lot of the life found in forest soil and active soils in general, giving them these chips helps fuel their growth and improves the soil overall. In addition, as those chips break down, they release nutrients straight back into the soil, fueling other growth, too.
Bark chips or trunk chips are still great. For more information, we have an article on wood chip mulch that discusses the benefits of these useful organic materials. But ramial wood is basically the highest quality of the bunch, likely because of its selective origins.
Since people are so picky about which young wood and shoots to prune, they can easily separate out diseased materials so those don’t end up in the mix, and the better nutrient density of the material is a major plus. This makes ramial chips a great resource for careful organic gardeners.
All About Ramial Wood Chips
Ramial chipped wood breaking down. Source: écomestible
Ramial chipped wood, sometimes also referred to as BRF for its French name bois raméal fragmenté, is a type of wood chip made from the small to medium-sized tree branches of young trees. The sapwood and young branches from hardwood trees like yellow birch, oak, chestnut, maple, and beech are the most desirable. The small branches are higher in nitrogen, allowing them to decompose and build healthy soil at a faster rate than older wood.
Using both small branches and fresh leaves helps to retain soil moisture, moderates ph, reduces pathogens and increases earthworm populations. In orchards, young branches can be “chopped and dropped” like a cover crop beneath fruit trees as ramial mulch.
The positive impact of adding ramial wood chips to your garden includes the production of humic substances. Decomposing fungi that aid in the breakdown of these wood chips can be classified into two subgroups. White rots use the enzymatic chemistry of amino acids on lignin-rich hardwood to produce humic and fulvic acids.
Humic acid increases nutrient uptake, drought tolerance, and seed germination. It also increases microbial activity in the garden soil. The brown rots transform softwood cellulose to produce polyphenols and allelopathic compounds specifically relied upon by evergreen species to suppress deciduous species which can help with weed suppression.
Additionally, new studies are showing that soil microbes metabolize polyphenols much like they are digested by the human gut.
The science behind this philosophy comes from the study of hardwood forests, wherein the deciduous trees there have been shown to continually enrich the soil that they grow in. This is vastly different from forests made up of conifers like pine and cedar trees which continually degrade the soil they grow in to force out competition from species that aren’t conifers.
In the mid-seventies Edgar Guay, former Land and Forest Deputy Minister in Quebec began searching for new products that could be derived from the huge piles of branches wasted after logging operations. The first field experiments with deciduous tree trimmings were made during the summer of 1978.
In 1982, M. Gilles Lemieiux began carrying out research on the role of trees and the formation of fertile soils at Laval University. He realized most forests are self-fertile and that the most fertile soils on the planet came from forests. He deemed this quality Jean PAIN. This led to his studies of RCW. He also learned the addition of ramial wood chips can raise the pH of acidic soils.
Ramial Wood Chips vs. Arborist Wood Chips
Linden ramial chipped wood. Source: arpent nourricier
Technically speaking, ramial wood chips are specifically made up of the slender twigs of young trees that are less than 7 cm or ¼ of an inch in diameter and may include foliage. Fresh branches and stem wood make for wood chips that are very different from commercially produced bark chips or arborist chips for all the reasons mentioned above.
Arborists’ wood chips used for pathmaking and mulch may include chipping branches that qualify as ramial wood, but they will also include all of the branches that happened to be chipped on that particular tree trimming job, which includes larger trunks and branches. These wood chips are just fine to use in your garden!
They just don’t have quite the same properties as ramial wood chips. Namely, they will be less nutrient dense and higher in carbon rather than nitrogen, and they come from parts of the tree that has a much larger diameter. Arborist chips are generally free since tree trimmers are looking to get rid of their waste product as mulch without having to pay to dispose of it.
If you catch your neighbor getting their tree trimmed the arborist may even be ok with chipping it right into your yard! There are also free chip subscription services where you can be added to a waiting list to receive a free chip drop when an arborist in your area has chips to dispose of.
Traditional bark chips come from, you guessed it, bark. These chips are usually the byproduct of the commercial logging industry, and it’s likely what you’ll find in your neighborhood big box store sold as mulch. They can be sold as chipped bark or shredded bark.
Shredded bark is particularly useful in farms for weed suppression since it forms a nice tight mat that seeds and roots have a hard time penetrating. These types of chips will be the least nutrient-dense as they come from the outer part of the tree.
It’s also worth noting that not all commercial brands are created equally. Some brands contain unnatural dyes that you might not want to use around plants you will be consuming like in your vegetable garden, but may be perfectly acceptable in your flower beds. Farmers may avoid some brands for this reason too.
DIY Ramial Wood Chips
As mentioned above, in orchards or on a farm, when completing tree prunings, farmers may choose to chop and drop the young shoots around the base of the trees as a rustic form of ramial wood chips as mulch. This method is perfectly fine. However, the shoots will break down more slowly on the farm unless thoroughly chipped.
If you or a neighbor happen to be pruning a hardwood deciduous tree, then you can set aside the slender young shoots, small branches, and twigs and turn them into ramial chipped wood. Commercial-grade chippers are available to rent at big box stores and may be worth it if you have a large amount of pruning to do.
How To Use Ramial Wood Chips
Incorporating ramial chips as mulch. Source: arpent nourricier
Now we’ll discuss different ways to utilize ramial wood chips in the garden. They can be used as filler for your landscaping, boost moisture retention in your vegetable garden, add nutrients to your soil and raised beds, and give your compost pile a boost by adding green materials.
Though they have many different uses in your garden and landscape, we’ll discuss the two most popular uses here.
In the Vegetable Garden
When using wood chips in the vegetable garden, it’s important to note that the soil must be allowed to “digest” the material for a few months. If not, it could rob the soil causing a temporary nitrogen deficiency, and you would need to provide additional nitrogen. This happens because wood requires nitrogen in order to break down.
But eventually, when it begins to decompose, this nitrogen will be released back into the soil. Professor Lemieux suggested incorporating fresh ramial wood chips directly into the soil in the fall. Fungal mycelia are not hampered by cold conditions, and they will continue to break down the chips throughout the winter. The result is that any risk of N deficiency will be over by spring and the soil will be ready for planting.
Spread a thin layer of chips over the surface of the planting site in the fall after your beds have been cleared from the previous season’s annuals. Come spring, the mulch will be significantly broken down. Mushrooms and other fungi work well with ramial wood chips turning them into stable humus, which is the key ingredient for great soil – just like the richest parts of the forest soils that M. Gilles Lemieiux observed in the deciduous forests he studied.
Some have asked whether or not composting the ramial wood chips prior to using them in your garden beds is necessary. When following the above-mentioned process, pre-composting is not needed. However, if you receive ramial wood chips in the spring or summer and wish to use them in the same growing season as spring or summer chips, then you may choose to place them in a pile to compost and break down for a few weeks before adding them to your beds.
Ramial wood chips decompose more quickly than chips from old wood, but they do decompose much slower than traditional compost additions. This pre-composting process will help them break down more quickly in your garden. Using ramial wood chips in your vegetable garden can benefit soil organisms and build healthy soil.
The use of RWC has been shown to reduce the number of pests and increase the presence of beneficial insects. Supporting the garden ecosystem starts with a healthy soil microbiome rich in nutrients!
Filler For Landscaping
A closeup of actinobacteria working to decompose ramial wood chips. Source: écomestible
Ramial wood chips are especially useful if you have an area with poor soil or an area that is plagued with weeds and invasive plants. Ramial chipped wood helps restore soil structure, increases drought resistance by retaining enough moisture in the soil, and smothers unwanted plants.
They can be used to prevent soil erosion on sloping areas by preventing the first layer of surface soil from washing away. This can be particularly useful if you have a section of your garden that is currently not in use or, for other reasons, is not ideal for cultivation (does not receive enough sunlight, poor soil, prone to flooding, etc).
If there is an unused area in your garden that you wish to prepare for future plantings, then you can apply a thick layer, at least 4-6 inches, of this mulch and allow it to decompose and naturally enrich the garden soil before planting. When using the mulch to smother weeds and/or invasive plants it’s best to provide an additional barrier for long-term results.
Allow a layer of cardboard to lie flat across the area, followed by a 4-6 inch layer of wood chips. This will smother any unwanted weeds and keep your unused soil protected. The earth naturally wants to grow plants, so uncovered soil that is not intentionally cultivated tends to harbor weeds and invasive plants once it has been disturbed or that natural habitat has been replaced.
These wood chips offer a way to protect those types of sites and provide mulch that breaks down into usable nutrients. Of course, these chips can also be used as mulch in the same way as traditional chips, around the base of trees, between ornamental plants, and forming patterns between rocks and other landscaping designs.
Frequently Asked Questions
Ramial chips in pile. Source: arpent nourricier
Q: How long does it take for chipped wood to decompose?
A: As a part of a regularly turned compost pile, they can decompose on the ground within about 90 days, especially during the heat of the summer. Spread it as mulch, and left unturned, the material can decompose in about 6 months.
Q: Can I put topsoil over wood chips?
A: Technically, yes, but whether or not you want to all depends on what/if you’ll be planting in that location. Some plant roots and vegetables are sensitive to disturbances in the soil (i.e., carrots and other root vegetables, which need light obstruction-free soil in order to grow properly). Other plants like stonecrops prefer rocky, well-draining soil. If you aren’t planting at that location for a while the chip is likely to decompose within a few months.
Q: Do wood chips make good fill?
A: Yes! If you have an unused area of your garden, then using wood chips as fill material is a great way to protect the soil from erosion and unwanted weed/invasive plant growth. They can be used to improve material soil quality for future plantings as well.
Q: Do fresh wood chips attract termites?
A: Ramial chipped wood and twigs are not necessarily an attractive source of food for termites. However, they do provide their ideal habitat by maintaining a high level of soil moisture. If you’re worried about termites infesting your home, be sure to keep a perimeter around your home clear of wood chips and provide good drainage away from the foundation.
Q: How deep should wood chips be?
A: 4 to 6 inches deep will help smother weed seeds and protect the soil by repairing the soil structure as they break down.
Q: Do weeds grow through wood chips?
A: Wood chips are an excellent natural method of weed control, especially when applied to the above-recommended depth. However, some very stubborn weeds and invasive plants may still find a way to put down roots and grow through your wood chips.