Notes On Densu Coir

Kimberly Moore, an associate professor in the Environmental Horticulture Department at the University of Florida, has spent parts of the last four years evaluating a product called Densu Coir, an organic and soiless substrate that’s produced from coconut husks. Moore shares her observations of Densu Coir and a summary of its performance in her research below:

Densu Coir Summary

In each case, we grew the plants in 100 percent Densu coir. The peat-based substrates were blends of approximately 60 to 80 percent Sphagnum peat with perlite, vermiculite, etc. All comparisons were unbiased experiments. Results presented do not constitute an endorsement of this product.

2009/2010

Densu coir was one of three substrates used to grow Jatopha curcas, a potential biofuel crop. Jatropha plants grown in containers with coir were comparable to growth in containers with peat-based substrate. This study is being published in HortTechnology this year.

October 2008

Densu coir was one of two substrates used to grow dieffenbachia plants. Average shoot dry weight of plants grown in Densu coir was 27.4 grams and average shoot dry weight in peat substrate was 27.3 grams.

March 2008

Densu coir was one of two substrates used to grow calathea. The fertilizer rate refers to controlled-release fertilizer incorporated into the substrates at low, medium and high recommendation rates on the fertilizer label for this type of plant

Fertilizer Rate Densu Coir (100%) Peat-based Substrate
Low 28.6 24.7
Medium 28.9 25.9
High 30.3 27.8
Average 29.3 26.3

March 2007

Petunia plants were grown in Densu coir, peat-based substrate or bark/sand substrate. A rating of 3 or higher was considered saleable. (1=dead, 3 = saleable, 5= superior). The first table below is a rating and the second table below is shoot dry weight. The fertilizer rate refers to controlled-release fertilizer incorporated into the substrates at low medium and high recommendation rates on the fertilizer label for this type of plant.

Fertilizer Rate Densu Coir (100%) Bark/Sand Peat Based
Low 2.3 2.1 2.9
Medium 3.2 2.8 4.8
High 3.5 3.0 1.0

 

Fertilizer Rate Densu Coir (100%) Bark/Sand Peat Based
Low 0.31 0.23 0.58
Medium 0.56 0.65 1.31
High 1.09 0.59 0.10

Advantages of Densu Coir

• Easy to work with
• Plant growth in 100 percent Densu coir was comparable to other substrates evaluated as long as fertilization was included. It works well with controlled-release fertilizer products applied as top-dress or incorporated into the substrate
• Wets easily and quickly; also re-wets easily if plants dry out between watering
• High moisture content
• Less dust when dry (easy of mixing and handling when dry)

Disadvantages

• Crop growth might vary; crops that grow well in peat-based substrates appear to grow equally as well in Densu coir.
• You have to add nutrients to the media to get good crop growth.
• Leachate solutions collected were very dark; hard to take accurate phosphate readings because leachate was dark brown.

The work summarized above does not imply an endorsement of this product. All studies were unbiased trials. The data is a fair representation of how the plants tested grew in various substrates. Results may vary with other plants as well as under different growing environments.  From the data we have collected, Densu coir appears to be a good substrate for growing a variety of plants.

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4 comments on “Notes On Densu Coir

  1. Anonymous

    Thank you for the information.

    I suggest you to include a growing media with 100% peat moss (Euro mix)in this study and compare with 100% coir. Several mix producers in Europe and Canada produce growing mixes with 100% peat moss. Details on our Euromix are available in the following link.
    http://www.theriault-hachey.com/en/products/growing-mediums/theuroxc

    Different substrates and crop species need specific adjustments in media pH,EC and physical/chemical properties for their best performances. Therefore to be fair in this kind of experiments it is important to manage those conditions in suitable levels for the test crop.

    Thank you

  2. Anonymous

    I like seeing confirmation of the good results I have witnessed in my own growing area. I suppose a follow up article might include the fact that when dolomitic lime is added one gets very healthy plants because coir lacks calcium and the naturally occuring high potassium interferes with magnesium uptake. Also if vermiculite is added, then CEC improves and plants do even better.

  3. Anonymous

    Thank you for the information.

    I suggest you to include a growing media with 100% peat moss (Euro mix)in this study and compare with 100% coir. Several mix producers in Europe and Canada produce growing mixes with 100% peat moss. Details on our Euromix are available in the following link.
    http://www.theriault-hachey.com/en/products/growing-mediums/theuroxc

    Different substrates and crop species need specific adjustments in media pH,EC and physical/chemical properties for their best performances. Therefore to be fair in this kind of experiments it is important to manage those conditions in suitable levels for the test crop.

    Thank you

  4. Anonymous

    I like seeing confirmation of the good results I have witnessed in my own growing area. I suppose a follow up article might include the fact that when dolomitic lime is added one gets very healthy plants because coir lacks calcium and the naturally occuring high potassium interferes with magnesium uptake. Also if vermiculite is added, then CEC improves and plants do even better.