Frequently Asked Questions Guide on Wood Fiber

by Brian Cantin, Senior Grower Advisor


1. How does NF Wood change my growing practises?

In all the trials, there has been a minimal change made to growing practises. However, regardless of which new mix is being trialed, there are always precautionary measures to take and recommendations to follow.

2. Will a grower need to adjust his water management?

In regards to water applied, the BM4 NF Wood does have increased water retention and early watering practices should be based on its ability to hold slightly more water. In retrospect, it has always been a recommendation that early watering practices for all mixes abide by the same precautions.

3. Will this mix help the shelf life of my plants?

The increased water retention will improve the shelf life of the pot. Several growers trialing the mix did indicate that the dry down period with the BM4 NF Wood was more predictable and their overall frequency of irrigations was reduced. Because there is a good reserve of nutrients due to the combined high Cation Exchange Capacity (CEC) of peat moss and NF Wood, a well-managed nutrient program should prepare the saleable product for post-harvest shelf life.



4. Will the wood rob nutrients or tie up nitrogen in the media similar to some bark mixes?

Internal research has found that there is negligible drawdown of nitrogen in mixes where the percentage of NF Wood is less than 30% by volume. Greenhouse trials done by growers have confirmed this observation and we have seen no evidence to indicate any immobilization of nitrogen. None of these trials have required feed practices out of the norm.

5. What types of crops should I use NF Wood for?

As with any soilless mix, discretion has to be used when choosing a mix. The one issue that always stood at the forefront of success has been those growers with a good understanding of water management. Consult your sales representative if you are wary about using this product for a particular crop. With access to Berger’s Technical Services and a team of grower advisors, they can provide the appropriate support.

6. Is the NF Wood product hydrophilic or hydrophobic?

With its low surface tension, this product is hydrophilic. In other words, it has an affinity for water which significantly improves water distribution and the wettability of the substrate.



7. What is the wood species and where is it produced?

In-house trials of different wood species were done in order to select the ideal raw material to produce the NF Wood. The NF Wood is produced in North America with sapwood residues of the pine industry. Sapwood is the active, living portion of wood where the sap flows, which is partly why the wettability and the CEC of this material are so good.

8. Does using NF Wood help our environment?

Since it is a natural by-product of the wood industry, it is sustainable and renewable. It utilizes a greener production process when compared to other aggregates typically added to substrates. Moreover, although it is very stable thanks to its manufacturing process, NF Wood is completely compostable due to the fact that it is composed of organic matter.

9. Why isn’t there perlite in the mix?

The interfacing and nesting of the NF Wood amongst the peat creates large cavities (macro pores) that allows for excess water to drain after irrigation. In essence, the NF Wood product acts as an aggregate and is an adequate alternative to perlite. It is important to realize that perlite is not the only component that can increase the air porosity of a mix. The quality and coarseness of both the peat and the NF Wood product are designed to produce an optimal aeration and porosity to enhance and help develop a healthy root system.



10. Can you use it as a germinating mix?

With the particle size that is produced through the defibering process, and the fluffy nature of the NF Wood, the BM4 NF Wood products are too coarse and growers will find it difficult to fill small cavities trays. Therefore, it is not recommended to use this product as a germinating mix.

11. Why does it root faster?

The coarse peat particles interface and combine with the intertwining NF Wood product to produce optimal aeration and porosity to allow excess water to drain and make oxygen readily available to enhance root production. Moreover, preliminary research has demonstrated that roots have an affinity for the NF Wood and appear to use the strands as a path which allows a more rapid development.

12. Will my crops grow faster in NF mix?

Physiologically, it takes energy for a young transplant or a young seedling to establish a root system. With a root system developing rapidly in BM4 NF Wood product, the plant can now shift its energy to producing vegetative growth.



13. How should I expand the NF Wood mix?

The same way any other Berger mix should be expanded; by fluffing the material carefully without causing excessive damage to the particle size and by adjusting the water to optimal levels for potting. This will allow you to get the full benefits from all of our growing media. This can be done mechanically (bale-breaker) for skyscrapers and 3.8 compressed cubic feet bales, or manually (by hand) for 3.8 compressed cubic feet bales.

14. How much water should I add while potting?

Ideally, you want to add enough water so that when you compress a handful of mix and reopen your hand, the ball of moistened material holds together. If it falls apart, you can add more water. However, very little water should be running out of the mix when you squeeze the material, only a couple of drops, if any. As a general rule of thumb, for most horticultural greenhouse growing media produced by Berger, you can add approximately ½ gallon (nearly 2L) of water per cubic foot of mix.

15. Why does it expand more than traditional peat moss mixes and how does this benefit me?

Unlike perlite and other solid aggregates which cannot be compressed, NF Wood is very compressible and also extremely light weight. In fact, pure NF Wood can be compressed up to 10:1 without causing any damage to the fibers. Moreover, since it has such a low density, the weight of the bale won’t increase significantly even though there is more material in each bale compared to traditional substrates.



16. Can I get this mix with CRF or biological additives (Rootshield®, Actino-Iron®, etc.)?

Like any other Berger mix, our formulations are customizable in order to cater to your particular needs. All custom mix requests go through a methodical process of evaluation that takes many factors into consideration including the agronomical feasibility. If necessary, we will run some tests in our laboratories or trials in our greenhouse to make sure we deliver a substrate that meets your expectations.

17. What are the advantages over other non-perlite aggregates such as rice hulls and peanut shells?

Rice hulls must be par-boiled to eliminate potential weed issues. They tend to attract vermin and have the propensity to migrate to the surface of the soil after irrigations.
Peanut shells can be problematic for workers who are allergic to nuts. They have a high salinity and additional fertilizer is required to compensate for nitrogen tie-down. Pasteurization is needed to eliminate weeds and nematodes that can be present in this product.
Moreover, you get a much more consistent and uniform result with NF Wood. Both rice hulls and peanut shells can either increase or decrease porosity depending on how they fall into the containers.


Please fill out this form to get the article in pdf format

  • This field is for validation purposes and should be left unchanged.