Has anyone tried compost activators?

Title: Involvement of microbes and enzymes in the pretreatment of woody seeds to overcome dormancy.

Authors: Morpeth, D. R.;Hall, A. M.;Cullum, F. J.

Editors: Ellis, R. H.;Black, M.;Murdoch, A. J.;Hong, T. D.

Source: Basic and applied aspects of seed biology. Proceedings of the fifth international workshop on seeds, held at Reading, UK on 10-15 September 1995.

Year published: 1997

pages: 261-277

Abstract: The addition of a compost activator, Garotta, to an otherwise normal commercial stratification medium for Rosa corymbifera cv. Laxa (a major rose rootstock) has been found to greatly enhance the final percentage germination. Germination increased from 21 to 81% in the field and from 10 to 88% in the laboratory. Commercial stratification occurs over 24 weeks for this species, consisting of 12 weeks at 25 deg C followed by 12 weeks at 4 deg C. Studies have found that whilst the cold period is critical, i.e. it cannot be shortened, the warm period can be reduced by at least 6 weeks. During this warm period microbes are encouraged by providing near ideal conditions for their growth, warmth, moisture and a food source (Garotta). It is suspected that the combination of these conditions produces the enhanced germination."

It sounds good. Are the seeds germinated in the same medium they’re stratified in? I couldn’t tell that from the abstract. As it happens, I do have some compost activator in the house (when I left it in the garage, raccoons got activated and tried to eat it). Now that I think of it, maybe raccoons could help increase the germinations as Enrique’s pet bird does, and as your cows do with the R. bracteata seeds.

To me, it sounds like they put the compost activator in the stratification medium and used the combination as the germination medium.

I was able to find another paper by the same authors. The abstract is given below. I was also able to get a copy of the full paper. Note, that this abstract contains one addition important piece of information. They found that if they first sterilized the seeds, the compost activator would not work. The compost activator worked by enriching the natural microorganisms which split the seed.

The pretreatment consisted of adding the compost activator to the seeds mixed in moist virmiculite then keeping the mixture for 12 weeks at 25 C followed by 12 weeks at 4 C. They then put the seeds on filter paper in a Petri dish at 20 C for the germination step.

Title: Microbial enhancement of seed germination in Rosa corymbifera

Jim Turner kindly pointed me here in response to a question I had. Henry, do they say how much compost activator is added and to what volume of solution? Very interesting.



Thanks for the link to the article, Henry.

From page 2:

"The commercial (control) treatment was based on moist vermiculite and seed (10:1 w/w vermiculite/seed). The enhanced treatment was achieved by the addition of GarottaTM (J. Arthur Bower

Several years ago I carried out experiments on seed germination (rose achenes) that included a modification of Cullum’s experiment using compost activator. This experiment was part of a university supervised research project and was performed using R. nitida, R. glauca, and pools of o.p. seeds from Buck and Canadian cultivars. Cold stratification for 12 weeks at 4C followed by germination at 15.5C (~60F) was the standard against which all treatments were measured. The experiment also included several variations of warm and cold stratification, as well as Driselase enzyme treatment using several variations of concentration and treatment time. The results of the experiment showed that the standard treatment of 12 weeks of cold stratification was the best all around treatment–being the cheapest, fastest, and least labor intensive.

What was interesting about the experiment was that the compost activator produced statistically significant reduced germination in two treatments. There were three separate treatments using the compost activator. Compost activator was combined with moistened germination mix in a Petri dish. The seeds were added to this mix. The first treatment was immediately placed into cold stratification, so no “composting” could occur. With the other two treatments, the plates were allowed to sit at ambient temperature in a lab for 6 or 12 weeks prior to the 12 weeks of cold stratification. They were moistened as needed and the plates were stirred weekly to simulate the “turning of the compost pile”. After 12 weeks of cold stratification, the Petri dishes were moved to germination conditions of 15.5C and checked weekly for germination for 6 weeks. The treatment that did not have a period of warm stratification prior to cold treatment, and the treatment that had 6 weeks of composting at room temp prior to cold treatment had significantly reduced germination. The treatment that included 12 weeks of composting prior to cold stratification had reduced germination compared to the standard, but the difference was not statistically significant. What was surmised was that the compost activator was not completely depleted in the first two instances. As the plates were moved to germination conditions, the composting resumed and the heat generated was high enough to induce a secondary dormancy. In the case of 12 weeks of composting, most of the compost activator had been used up, although not entirely. Germination began to improve but was still not as good as the standard treatment.

This is a long way of saying that if you want to try treatment with compost activator, the seeds should be removed from the composting treatment and rinsed or sanitized prior to being placed in germination conditions. Also be aware that the the entire length of time required to achieve germination could be lengthened.

If anyone is interested, the only other finding of note in this experiment was that germination of R. nitida improved to a statistically significant level when a 6-week period of stratification at room temp was used prior to 12 weeks of cold strat.

Julie, I have not seen your experimental details so I am only guessing at the possibilities that I am here presenting.

Your statement: “As the plates were moved to germination conditions, the composting resumed and the heat generated was high enough to induce a secondary dormancy” seems to indicate that you used a different type of compost activator than used in Morpeth’s Ph. D. thesis. What were the components of your compost activator? Also, did you use a germinating medium that the compost activator could react with such as peat? Also, did your compost activator contain digestive enzymes or microbes?

Their germinating medium and activator were:

" Seeds were mixed with vermiculite, an inorganic medium with good water retention properties, since it is essential to keep the seeds moist during temperature pretreatment (Gordon and Rowe, 1982; Gosling and Aldhous, 1994). Vermiculite contains no nutrients and was sterilized (autoclaved) before use.

Seed samples were subjected to different pretreatment conditions (Fig. 1). The commercial (control) treatment was based on moist vermiculite and seed (10:1 w/w vermiculite/seed). The enhanced treatment was achieved by the addition of Garotta’M (J. Arthur Bower’s, Lincoln, UK), a commercial compost activator (10% w/w GarottaT"'/seed). This activator is a widely available sterile product consisting of a mixture of inorganic mineral nutrients such as calcium carbonate, ammonium salts and phosphates (Morpeth, 1998). Any visual changes in the physical properties of the seeds were recorded on a weekly basis. The control and enhanced treatments were applied to fresh collections of seeds, from the same stock bushes, every year from 1992 to 1996. Detailed data are provided for the 1996 experiments."

They depended on the natural “bugs” found on the seed to eat the seed coat (when they used sterilized seeds, the compost activator did not work).

I “suspect” that you either used a degradable germinating medium or a compost activator that contained active enzymes and/or microbes.

You mentioned that you also did enzyme experiments. Please give more detail on your enzyme treatment experiments as I was able to get results similar to what Yambe et.al. reported ( http://home.neo.rr.com/kuska/enzymeuse.htm , please follow the links from that link).

The following is another enzyme treatment paper:

Title: Coffee (coffea arabica L.) seed germination after treatment with different concentrations and embedding times in cellulase.

Authors: Sales, Juliana De Fatima; De Alvarenga, Amauri Alves; De Oliveira, Joao; Nogueira, Francisco Dias; Rezende, Lucio Costa; Silva, Fabiano Guimaraes.

Authoes affiliation: Fisiologia Vegetal-UNIVERSIDADE FEDERAL DE LAVRAS/UFLA, Lavras, Brazil.

Published in: Ciencia e Agrotecnologia , volumn 27, pages 557-564, 2003).

Abstract: “The seeds of coffee trees germinate slowly, because the seeding is done soon after the crop is harvested, which coincides with the cold period of the year, and also due to the parchment, which constitutes a barrier that hinders the absorption of water for the seed. Aiming to evaluate the effect of exogenous application of cellulase enzyme to coffee seed germination, an expt. was performed soaking coffee seeds, cultivar “Acaia do Cen-ado”. in cellulase soln. at different conchs. (0, 1.6, 3.2, and 6.4, g L-1) in 0.05 M K-citrate buffer at pH 4.8 for 0.72 and 144 h. It was found that the cellulase enzyme at the concn. of 6.4 g L-1 provided the greatest index of speed germination and the greatest germination percentage when the seeds remained in contact with the soln. for 144 h.”


Your guesses were right. The composting/stratification/germination medium was peat-based PGX by Promix, which would have a source of nutrients for composting–this was actually a desired characteristic of the medium to be used. In addition, the compost activator (Greenview Certified All Natural Organic Compost Activator Plus Enhancers) included both a nitrogen source as well as microbes. At the time the experiment was set up, the model was the little information on the experiment that was printed in the 1994/95 winter Rose Hybridizers’ Association Newsletter. There was no in depth information available on the Garotta brand compost activator or how it worked, so it was assumed that it would be similar to most of the commercial activators that can be purchased locally which usually contain both digestive microbes as well as a nitrogen source such as the poultry manure in Greenview–we were actually looking for those qualities. Our intent was to weaken the seedcoats by digestion. The fact that the Garotta merely fed the natural microbes and enhanced their activity is very interesting–not exactly the more traditional concept of composting. I wish that I had had the article by Morpeth and Hall when the experiment was designed back in 1996. Your information really helps to clarify some things.

Part of our intent with the project listed in my previous response was also to mimic the large variety of genotypes that are encountered in a rose hybridization program. Do you use a single variety in your experiments? I haven’t read about your enzyme experiment yet, but will get back to you after I do so.


I just want to thank you for all the time and effort you take researching all these horticultural publications. While many would be beyond my level of understanding your input makes them interesting and sometimes useful.



A small update:

Seed Science Research, 10(4), 489-494. (2000)
Microbial enhancement of seed germination in Rosa corymbifera ‘Laxa’
DR Morpeth, AM Hall
Published online by Cambridge University Press: 22 February 2007
Germination of native tree and shrub species from seed can be unpredictable. Germination of Rosa corymbifera ‘Laxa’ was 2% under normal commercial conditions. This was obtained in the presence of the natural microflora found on the seeds. The microflora originated on the hips and the seeds become inoculated during extraction. Exclusion of microbes from such pretreatments resulted in no germination. Inoculation of surface sterilized seeds with members of the natural microflora resulted in 3% germination. The addition of Garotta™, a commercial compost activator, to the commercial pretreatment increased germination to 95%. This high germination percentage was sustained over a 5 year period using seeds from the same stock bushes. Addition of the compost activator resulted in a 20-fold increase of microbial activity in the pretreatment mixture, indicating that enhanced microbial growth resulted in higher and more predictable germination percentages.

Seeds: Ecology, Biogeography, And, Evolution of Dormancy and Germination
By Carol C. Baskin, Jerry M. Baskin · 2014, p. 51
Also, in “seeds” of Rosa corymbifera, softening of the endocarp with microbes in compost reduced the warm stratification requirement from 12 to 6 wk; “seeds” still required 12wk of cold stratification to germinate (Morpeth et al., 1997).

What is Garotta made of?
Active ingredients - Nitrogen with ground limestone.
Recommended Uses - For composting all garden and kitchen waste. Provides food to promote bacterial growth, kills off weed seeds and converts garden and kitchen waste into a rich compost. Can be used for composting all garden and kitchen waste.

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