Cannabis Cultivation and Science Podcast Episode 5

In this interview, Tim Wilson aka "MicrobeMan" talks about aerated compost teas, living soil, root exudates and vermicomposting. He gives some great advice for those who want to try out compost teas and build living soils.


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Tim Wilson Microbeman


Tad: Welcome to the Cannabis Cultivation and Science Podcast, I'm your host Tad Hussey of KIS Organics; this is the podcast where we discuss the cutting edge of organic growing from a science based perspective and draw on top experts from around the industry to share their wisdom and knowledge.

Our guest today is Tim Wilson of Microbe Organics. Some listeners may know him better as Microbeman from his helpful posts on many internet forums; Tim is a long time friend and colleague who has taught me much of what I know regarding microscopy and evaluating compost teas.

I consider Tim to be one of the foremost experts and researchers on aerated compost teas and microbial amendments in North America; Tim also founded, a free forum for gardeners that has a wealth of information. I am honored today to have him on the show!

We have Tim on here today one of the first things I would like to talk to Tim about would be to hear a little bit more about your background regarding growing cannabis in Canada, you have a pretty unique history there I'd love to hear more about that style of growing and how you did it. If we could start with that, that be great.

Tim: Sure OK so I guess starting back around 1995 or so is when I kind of more seriously got into growing cannabis starting with outdoors and then slowly moved it indoors. And a couple of years after that I ended up having an association with The B.C. compassion club society which provides strictly medicinal grade cannabis to at that time it was around 1500 to 2000 patients now it way up there who knows. But at the beginning we just started out doing basically what everybody else was doing with the pots and you know like a five gallon pot under the high pressure sodium lights and then at the end when we harvested it we would just dump the dirt out and use it in the vegetable garden or something like that. And then it just started occurring to me that this was kind of stupid to be wasting all that; so we graduated from there to just starting to remix the media as we went along each time adding some more compost to it and I should mention too that we had also started out just using typical chemical mixed fertilizers checking the EC, PPMs and all that stuff and we sort of have started at the same time graduated at the end of that when we just started using compost and some more natural fertilizers and at the same time we had been expanding our outdoor gardens and in the outdoor gardens we didn't mix anything up every year we just left it as if it was a vegetable garden and the plants outside were doing just as well if not better than the indoor plants so then I thought why don't we just try to move outdoors indoors and so we pretty rapidly graduated to using bins and I guess that would have been around 1999 or 2000 and something like.

The problem being with the bins is that they take up so much space and you can't move them around and so then we just got the idea of building bins which could be stacked on top of each other with the lip sort of facing out so there was a little space to get into to plant the young plants, the rooted cuttings into and just hung three high pressure sodium lamps in the in the center and have the four boxes stacked high and I guess around seven stacks or something around the lights; we just stopped doing any digging up of the soil just let it be and you know at first I thought this you know there's no way this is going to work but we experimented with one set, it worked fine we just top dressed in between harvests we would inoculate with fermentations like EM fermentations and that sort of thing.

The only prepared thing we were using then was fish hydrolysate. Other than that we just made our own compost teas. With that system we would allow the plants just to grow up over about ten days to fourteen days then we would just change the light to the twelve hour cycle and then start flowering them so that the whole turnaround time was close to 60 days, 64 days something like. The plants were only eighteen inches tall approximately when we harvested them but doing it like that we got the same yield as we were getting before where we were growing these larger plants and over a longer period of time and so we ended up getting actually a higher yield that way. Anyway I don't know if I described it exactly perfectly or anything but ask any questions about that.

Tad: Yes I was wondering what size were these bins that you're describing and also what was your media in the bins that you kept reusing?

Tim: Yeah OK so the bins were about 30-36 inches long and 14 inches deep and at the bottom there were about probably 10 inches wide and then with the slope out to about 14 inches at the top and making the initial mix you know we found over time with experience after we started the other bins is fairly important we tried to have a combination of things that stay in place for drainage for a longer period of time you know over the whole life of the soil basically; so we used things like fine gravel and pea gravel and that sort of thing.

For that component, intuitively I just thought let's use as many different colors as we can whether that makes sense scientifically who knows but just in keeping with the human diet that supposedly if you eat a variety of color things you get a variety of minerals and nutrients so that was my idea with that and then of course we mixed in sphagnum peat moss and topsoil from outside and vermicompost that we raised ourselves in a big heap in a barn full of worms.

Tad: Can we talk about that too Tim? You have a unique from a composting style and I've seen the microbial results of your vermicompost and it's always fairly superior to pretty much everything else I see; I’d love to share that with listeners too.

Tim: OK well so do you think I finished off the other mix there satisfactorily I mean? I know it's my way of doing it is quite different and really I count on the soil coming to life and having a life you know that's ongoing so the microbial population stays in there and doesn't get disturbed and I think that's really what contributes to the success of the whole thing. And I should add too that as far as pests go like insects that chow down on the plant and root suckers and stuff like that we were really fortunate in that when we brought in some of the topsoil and the vermicompost from basically outdoors we also brought in some rove beetles and they were just indigenous to the area and they basically kept the pests in balance and it was just amazing that we have success that way but in addition to that we had also we bought some cucumeris and some persimilis and both of them we also had another room where we had 18 hour light going all the time and both of them multiplied on their own. Why? I don't know exactly, I didn't give them anything special to eat or anything like but especially the cucumeris just propagated like crazy so whenever we needed them in another room we would just dig some up and take them in and move them around.

And I should mention that the longest time that we had those bins going without mixing up the soil was seven years and the other ones were about five years and they just got interrupted because our contract was question by the authorities and we had to sort of shut down. But with the vermicompost we had two different methods that we used for that; one like I said where it was just done in a big heap in a small barn that we had built for that purpose and we piled up horse manure that we got from our field and we usually pick out the stuff that semi dried out and mixed in some sawdust and straw sometimes but it was almost all horse manure and into that we would mix some wheat bran that was very cheap to buy at the livestock supply store, some alfalfa meal at no greater than five percent because I fell into the hard way that if you put too much alfalfa meal in the nitrates just kill the worms, and we also put in some peat moss into that and I didn't say kelp meal yeah kelp meal as well. So we put in as much kelp meal as we could afford to get the time which wasn't very much because it's a more expensive as an ingredient. But the important part with out is that we left it for a long time so basically our worms were neglected you know and we didn't harvest it out on a continuous basis; so my opinion is that because the worms were sort of forced to keep on re-digesting what was there and to digest every little scrap they could find instead of having new food given to them, they produced a superior quality and our vermicompost which is not typical looking like the castings that you see in the bags; there was sort of real gooey gummy stuff anyway and then the other method is that we use the same basically the same ingredients except the added kitchen scraps as well and raise them in big plastic bins but also subjected them to staying in there for a very long period of time.

Our method of harvesting the worms was to use those plastic mass transplant trays; we will just fill them up with the worms favorite food and cover that over with wet newspaper and then lay them all over the top of the worm pile they would crawl up in there and we will just snatch them off and then gradually throw them all into a big bin and then come in with the tractor and clean the barn out obviously we also scooped out some of the worms and the castings of course.

Tad: So one of the things we've talked about already was just the importance of the microbial communities in the soil as being the most critical factor for allowing you to have this system where you could go five to seven years without disturbing the soil. Could you give listeners a little background into the microbial loop or living soils as you call them?

Tim: Yeah sure OK so first off you know with a living soil microbes live in hierarchically so that there are some microbes that have evolved to function close to the surface of the soil and some half way down and some way down at the bottom you know where there could be rocks or whatever and so the ones that are at the surface are the ones that decompose things the fastest and scientifically it's called the detritusphere where detritus, shit and all of that branches and leaves and everything fall on there and so they have at their disposal all kinds of fuel you know they can use the oxygen which is abundant, nitrogen is abundant you know light even that some microbes uses is there too if they need to; so that's the fastest area that things are degraded and then the altered component of what was degraded is then passed on to the next set of microbes etc. So that's sort of a basis of why you want to leave your soil intact and then you know if you're outside or if you've put some sort of rocks or minerals at the bottom of your soil mix then possibly you have the mineral microbes that will therefore pass some minerals up the scale instead of down the scale.

As far as the actual nutrient loop goes the biggest players in that are the bacteria and archaea should take a minute to say that archaea are lump in with bacteria because they're absolutely indiscernible; if you are looking at them with a microscope and for many years we've thought that it was all bacteria that we're looking at it's only been in you know the past twenty years and you know getting more and more that people are discovering that archaea are everywhere and that maybe they are just as or even more responsible for the mineralization of nutrients but anyway so I put those together bacteria and archaea. They process organic matter or minerals and then they are consumed by protozoa and in the protozoa group the two important ones in our soil that we're looking for are flagellates and naked amoeba and so they use only 10 to 40 percent of the energy that they intake from eating those other organisms and the other 90 to 60 percent is expelled in an ionic form that's directly available to the roots of the plants; that's really an economic thing for the plant because then it doesn't have to expend as much energy to gain nutrients you know that would take us into another topic to talk about root exudatations but I don't know if we want to get there quite yet but I don't know if I explain that as simply as possible- to put it in a nutshell the protozoa eat the bacteria and poop out ions that the roots can uptake that are already you know in a form that is available to them.

Tad: No that's great I think the way I usually explain it is when we're putting out Miracle Gro or any type of chemical around it you treat we're directly feeding the plant that's coming in direct contact with the roots; plant grows. When we put it right organic fertilizer like alfalfa meal or kelp meal we're not directly feeding the plant but all this microbial interaction is what causes these nutrients to be changed into a form that the plant can then uptake.

Tim: Yeah true that's exactly what happens and if we do get into this a little bit, the bacteria, archaea and fungi that initially degrade the nutrients have organic acids that they excrete for that purpose and the plant roots have the exact same organic acids that they utilize or very similar anyway to release nutrients as well . That’s how plants could do it without the organisms there to cycle the nutrients; you have some of the nutrients which are stored in, adhered to the organic matter or clay particles are stored as we everyone knows as cations and they have certain net positive charges.

A lot of guys talk about how you have a certain balance of soil and along comes another charge and lo and behold the nutrients is released from the organic matter or the clay and is then available to the root but it's not 100 percent that simple or maybe it is simple, but it also occurs from it is caused by the organic acids I talked about so if you have say you have like calcium it's got a plus 2 positive charge; so we've learned that it is released by hydrogen. So if we look at you know one of the organic acids say citric acid which is very common, it has eight hydrogen bonds on it; so if you consider that those if you divide the two into the eight we get four so that means the citric acid could release basically four units for want of a better word of the calcium nutrient and so these organic acids are actually released by the roots and by the microorganisms; it isn't something that just happens because of having a certain mix in your soil at least in my opinion. So do you follow what I mean or is that too crazy?

Tad: So these organic acids that are produced both by the plant roots as in the form of an exudate or by these microbes in the soil you're saying is what's essentially making these various plant nutrients available to the plant in the ionic form?

Tim: Yeah it is actually what releases from where it's stuck you know the cation exchange capacity, it where it stuck to the organic matter or the clay particle; so that it's the trade of the hydrogen atoms that make up the molecular structure that actually releases equal amount of nutrient from the positive charge cation. So it's the roots of the plant and the microorganisms that are making that happen.

Tad: That's why I would say it's important in your soil mix to have a microbially-active media meaning adding in vermicompost or having a high quality compost fraction in there as well as a good peat moss is a good way to increase that nutrient cycling. Would you agree?

Tim: Yeah absolutely and like with peat moss it's got a really high CEC so it has a large capacity to hold nutrients which are then available on an ongoing basis.

Tad: So the plant could control what nutrients become available by the exudates it’s feeding to the microbial populations in the rhizosphere as well as the organic acid is using to break down some of these nutrients itself. Is that correct?

Tim: Yeah basically it's kind of complex beyond complete simplification but in my mind I sort of simplified it in even though the roots can excrete these organic assets to get the nutrients themselves, they can also excrete amino acids and sugars that attract certain bacteria to them and so then by attracting and feeding those bacteria, the bacteria increase vastly in population very quickly and sol that stimulates the protozoa to come out of their cysts to encyst and then they begin dividing; so as the bacteria release the basic nutrients that we talked about with the excretion of their organic acids and then the protozoa begins feeding on them they basically multiply the amount of nutrient that would have been unavailable to begin with.

So for the economy of the plant it makes great sense that it has released this energy in the form of the amino acids and sugars to start feeding these bacteria to begin with; it's almost like when you watch a compost tea developing right when you start it up and then you feed it some molasses or whatever food stock and the bacteria are just about the first thing to begin multiplying and then because of that the existence of all those bacteria it stimulates the protozoa to come out of their cysts and to begin to divide as well. So it's kind of the same thing it's going on but it's in the soil.

Tad: So let's talk about this before anyone takes this concept and starts dumping sugar all over there plants; can you explain a little bit more about maybe a little about molasses and different sugars and then also what happens when you put too much of it, what happened when these bacteria reproduce too rapidly.

Tim: If the bacteria produce too rapidly you mean in the soil or do you mean in a compost tea?

Tad: I'm want to save compost tea for just a second I'm talking about just in the soil I have kind of leading you to a question but I think you're going to get there so what happens if we add let's just say too much molasses in a soil, what's going to occur?

Tim: I'm not really sure you know I can't say and I don't know what too much is, but too much of anything is not good and so I would just guess that if you put too much molasses in there you know get an over abundance of bacteria and they may end up eating everything in sight it depends on what you have in the soil to begin with you know because molasses is a food for fungi as well as bacteria so it does make some sense to just apply some diluted molasses occasionally to soil they use molasses I don't know if you know about this but if there's like an oil spill in a wilderness area they pour diluted molasses into the soil to stimulate the bacterial population that will consume the oil.

Tad: I didn't know that. Now what I was getting at is you have the potential for the bacteria to multiply so rapidly that they could actually create a temperature increase in the soil around the root zone which could cause the plants to suffer or that the bacteria could be more efficient in accessing that food source to where it could pull nitrogen and other nutrients from what the plant could access.

Tim: Yeah that's a possibility for sure.

Tad: That's kind of what I was trying to get at just to caution listeners.

Tim: Well you caution with everything; the same thing can happen if you put a mix like wood chips or something into your soil. Wood chips that are not composted or aged the same thing can happen the bacteria and maybe fungi I will use up all of the available nitrogen in an effort to degrade those wood ships and so then they lock it away from the plant; that's why I don't like the idea of burying things down in the soil for the plant to come up on some time in the future or whatever because that's always a possibility for that to occur if you put some sort of raw organic matter down there that is not stable.

Tad: Are you talking about Hugelkultur beds or are you talking about the layers because I've heard some of the people like The Rve recommended with the True Living organics.

Tim: Some of the layers sort of thing the spikes some guys say that they have great success if they put a dead animal at the bottom of the pit before they plant and stuff and sometimes that works so great you know it's just it almost seems like it's happenstance that sometimes there's a lock up and sometimes there isn't; I've been caught for sure with my pants down with that one by mixing stuff in too soon.

Tad: OK so let's change direction a bit here and talk a lot about soil testing; so I know that certain groups like in the past I've heard some people claim that if the all the nutrients we need are already in soils we just need to add the right microbial populations they'll meet these nutrients available whereas there's other groups that will say hey if we get the right mineral content balanced in the soil and everything is you know the soil is minerally-balanced then these microbes are just going to appear and start reproducing and then we'll have optimal soils. Can you give me your sort of take an experience on all of this?

Tim: Well I don't think that every soil everywhere will produce whatever you need just because it has a good microbial population, there may be certain soils in some areas that you can say about. I'm in the group or maybe by myself where I think it's important to include as many diverse nutrient components as you can within reason and that's why you know we used so many different things and in our soil mixes like the different we would take stone from one area and use the Vermin compost and that sort of thing and that's what I think is necessary; I haven't bought into the whole balanced soil of thing because the way I've been looking at the way that plants and microorganisms work together to acquire the necessary nutrients sort of goes against that in my mind because I think what you're saying when you say if you have a balanced soil and then all of it'll cause this to release that and this will be available instead of being locked up and it sort of goes against the plant being sort of having an influence over its environment and as if it's just something that's being held up and sucking up nutrients . Whereas I think it really does work it's kind of the way I describe the plant as working in contact with the microorganisms and the organic materials that are around it and those can be inorganic matter, can be compost, vermicompost, powdered rock minerals, clay powders whatever. So that's why I like to put within reason as much as I can but balance that as far as the soil being able to breathe and drain and that sort of thing at the same time. I don’t know if I answered your question or not.

Tad: You did and you didn’t so the physical properties of the soil totally agree with in terms of the amount of porosity, drainage, aeration. When we talk about a soil though let's say you have a soil that is deficient in calcium that calcium has to come from somewhere. So there is something to balancing the soil and saying “hey I just did the soil test this is obviously low in calcium, I need to raise my calcium levels up to X.” Whatever that level is that you want to set it at. I totally agree with you in terms of the fact that… mineral balancing is just certain people's best guess whether it's you know Kinsey, Albrecht, Solomon you know, Michael Astera all of these guys are just you know Kerry Reams they're trying to guess at what they think is optimal for plant health for various crops but we don't know there's just hasn't been enough research it seems like to me in that regard.

Tim: Yeah well so I haven't said you shouldn't have calcium or you shouldn't have all of the components possible what I am saying is that they should be there but they don't necessarily have to be there or in the certain ratio is that someone has delineated; that's all. So sure you could end up with some soil that's deficient in calcium and then sure you need to add some component in that's going to supply the calcium absolutely.

Tad: So you're saying don't get too caught up or freak out if your potassium is not it three to five percent of your CEC or your calcium is not sixty to seventy percent or f that sort of thing.

Tim: Yeah right that's what I mean yes but whether I can't say that I'm one hundred percent right but that's how I grew. But definitely you know you try to include everything that you can then and it all depends on an individual circumstances; some people can afford to send away to Timbuktu for whatever ingredients right? Others like where we were, we were on a farm ninety miles away from the closest town and so we used what was at hand and made what we could make. Lucky I guess we did have all of the necessary components existence in the materials that were around the area.

Tad: We talked a little bit about soils and you talked about the importance of these microbial communities in the soil. The way I met you was actually through a discussion board hosted by Jeff Lowenfels on aerated compost teas and I consider you one of the foremost experts on the continent when it comes to this subject so I would love to kind of dive in a little bit to that if you have time right now to discuss a little bit more about what aerated compost teas are, what they are not, and what you would recommend for people that are just starting out using compost teas?

Tim: OK so what is aerated compost tea? It's basically a water base that’s got air being pumped into it and it's being agitated and compost is added and the agitation extracts the microorganisms that are existing in the compost or vermicompost. And a food source is provided that feeds the bacteria, archaea and fungi that are existent and in your compost and as they multiply it stimulates, as I said before, the protozoa to come out of their cysts and begin to divide and multiply as well. So over a period of time, the population expands and reaches a sort of an approximate ratio where you have lots of ….but you can see if you use a microscope lots of bacteria and protozoa; the protozoa are eating the bacteria so that's when the nutrients cycling is occurring and it’s at its peak and if so that's your purpose for using the compost tea that is the time to apply it.

Tad: Now what's the window when that generally occurs?

Tim: For me thirty six hours is pretty safe if you're not using a microscope that's a good time. People talk about different recipes and making a fungal tea opposed to a bacterial tea anyway it doesn't really work that way as far as recipe goes. Although you can have some influence with the recipe it's more the timing. So obviously if you want to have straight bacteria in a tea it's going to be in the first probably twelve hours that you want to use it. However if you do have fungi in your compost it's going to be growing at that time as well; so I’ve never successfully managed to have a compost tea that was either fungal and with no bacteria or bacteria with no fungi, if they both exist in the compost used. They pretty much grow at the same rate at least in what I've done. So if that's what you want then you want to probably use it between twelve and eighteen hours but after twenty four hours it's usually when the protozoa reach their peak or come start multiplying I should say and reach their peak at thirty six hours. And so if you want nutrient cycling that's when you use it. As far as methods of making compost tea we made everything; we made everything from you know one litre brewers up to twelve hundred gallons. We had straight air stones, we had you know others that were copies of what other people had with the air going down a cylinder that had to compost in it, then we used venturis which are made with water pumps and airlifts. And airlifts are the most successful way of doing it for sure as far as agitation and as far as dissolved oxygen. You know there's mathematical papers that illustrate an airlift can up the dissolved oxygen capacity ten-fold from an air pump that's just blowing into air stones. Anyway so that I get sidetracked there and forget what I was saying.

Tad: No I think that's interesting, I just want to I want to reiterate that when Tim says that he's tried all these brewers, you're also you've also looked at them under a microscope and you spent hours and hours in your laboratory. It's not a matter of you just looking at a bucket of brown water and saying “oh this looks good” or throwing it on a plant you're actually spending time looking on slide after slide and examining all of these teas.

Tim: Yeah we took the pH and TDS and everything. Every single brew I've got several notebooks still full of all of the notes from there and took the dissolved oxygen readings of course and temperature; the whole works.

Tad: I want to back up just a little bit one thing you're talking about with this bacterial dominated or fungal dominated teas. I just want to make it clear when we talk about teas that's fungal dominated there are still going to be a ton of bacteria it's not like that like you mentioned briefly the bacteria is not going away and vice versa and it's really the brewing length that controls that more than the recipe right.

Tim: Absolutely!

Tad: Great! So I just want to clarify that and then let's talk a little bit about what happens when you brew perpetually or you brew longer than thirty six hours because I know this is something that certain companies in the industry are promoting that you and I feel rather strongly about already. So let's talk about what happens on a microscopic level.

Tim: Well once you go beyond forty eight hours is pretty much a maximum before the ciliates, usually it’s the ciliates start taking over the whole thing. Sometimes it's the flagellates but in my most in my experience ciliates start coming into play. Ciliates are the larger protozoa that are sometimes an indication that there are some anaerobic bacteria in the picture because that's their favorite food like if you go up to seventy two hours or even beyond that. You just end up with a ciliate soup. I've got some video footage that you know I don't know if I ever showed it to you, but it would blows my mind it's just like the whole slide is just teeming teeming ciliates; it's just amazing! If there's someone who has perpetual brewer going in a store and then selling teas to customers, I mean that's possible to do but every thirty six to forty eight hours you really should reconstitute it. And so that means put in some more compost, and put in some more feedstock. But what happens is that once you do that you're going to have to wait for you know twenty four hours for it to basically go through the whole cycle that it goes through to come back to being a useful product again. So if you're perpetual brewer and you're selling tea you know, pity the customer that comes in after you've just added new stuff to your brew they're going to get something that the dissolved oxygen hasn't had a chance to build up and the microorganisms haven't been properly extracted or multiplied and they're going to get a totally different product from the customer who gets it at thirty six hours. So that's what's wrong with perpetual brewing. If you're doing it for yourself at home, and keeping track and you have a microscope, or even you just want to experiment, you know go for it. But if you're selling it to somebody that's just not very culture.

Tad: You bring up a good point though. I found it was very challenging to try and maintain good microbial diversity and biomass, even when adding food stock and using a microscope beyond you know forty eight hours. So when we were doing those trade shows together, for example, where we had a microscope and we had a brew going and we would pull samples, and add food stock, and try and maintain the brew, even with a microscope and looking at the samples every I don't know fifteen twenty minutes it was still very challenging to maintain that compost tea and I didn't really feel like we did all that effectively.

Tim: No it wasn't very good; no, you're right.

Tad: So I totally agree with you that's why when we brew at our farm we will just tell customers “compost teas are available on Saturdays” and that's when they can come in, it'll be brewing throughout that day so they can get something to take home and then we'll shut it down, discard whatever we have and start over again for another day sort of thing.

Tim: yeah that's the way to do it.

Tad: So a company they're saying you can put compost tea in the fridge;?have you heard of that one there's a company that said that?

Tim: oh yeah there's all kinds of stuff on YouTube these days

Tad: So I just want to say that that doesn't really work very well either. I don't know if you've experimented with refrigeration or any of that sort of thing yourself ?

Tim: Yeah we did put some in the fridge when we were doing all of our experiments and stuff and it wasn't worth a damn. The microbes basically just died or go dormant, and they don't come back again unless you know you might get them back again if you add it into a compost tea and brew it over again. When we did have to store some tea, we did it with removing the compost because it was a case where we had it in a bag so we could remove it and then aerate it and the longest I kept it that way was over a period of three days constantly aerating it and even then you know slowly degenerate. And what you say about putting it in a bottle you know that reminds me about you know when people send a sample to get tested, the whole thing is going to change during the shipment so by the time it's tested if you're trying to say well this sample was taken at twelve or thirty six or forty hours by the time it's looked at the lab it's not going to be that time any more it's going to be 50 hours or however long it took to get there and it will have transformed. I don't know if I should say this, but I had a client who was in a bind that he had a customer, a big customer for a landscaping deal who insisted that he would not contract with them unless he had a good test result from a lab, so he asked me what's what he should do and so I said well just brew for eight hours, put it in a bottle and ship it and by the time it gets there it'll be good and so that's what he did and it was perfect and he got really great test results and got the contract.

Tad: Yeah I think that is a challenging aspect with the whole idea of testing. It’s really expensive and I like to point out to people who are doing those types of tests that not only does it have the challenges that you just listed, but you change one thing about your brew, that snapshot really doesn't allow us to make useful decisions in the field in terms of how to improve our compost teas in my opinion, and that's why I think having a microscope is so useful if you really want to get into that aspect of growing. One thing I do want to bring up that you kind of hinted that there is…I don't want to discourage growers from experimenting with compost teas and trying them out on their plants and it's really hard to truly screw up.

Tim: Yeah it's very difficult to make a bad compost tea; I tried the adage of having an anaerobic stinky tea and dumping it on a plant that I want to kill and the plant actually loved it. Anyway, one thing I wanted to bring up is recipes but something else I've sort of learned in my old age is that I seem to get just as good results from just using vermicompost with molasses and you know I do have the recipes that are on my web page that a lot of people just they say that's what they use, they stand by it and it's great and all that, but you know all power to them and their if they like it stick with it. But for me I found that I stop including all of the things like rock phosphate and kelp meal and fish hydrolysate and just stuck with the molasses and the vermicompost and got exactly the same microbial population growing in there.

Tad: Sure we use a product that we called microbe catalyst with ours as a food source not because there's anything wrong with molasses but just because it's a dried granule and molasses is hard for us to package and ship. But when I don't a lot of my microscope testing I actually use molasses and you showed me that and I will say I do really like to use organic alfalfa meal in addition to molasses and vermicompost as part of your recipe, when they use your recipe but the just the molasses in vermicompost works really well too.

Tim: Well molasses has got a bad rap somehow I think it all started with some testing that was done in two different labs; one was a U.S.D.A. lab another was the Canadian agricultural lab and they were trying to show that e. coli would grow in aerated compost tea and I can't remember exactly but I think both of them had some sort of set up where they were using jars with air stones which is OK you know it just for experimental purposes but they also inoculated; both labs inoculated with e. coli and so if you put e. coli into an aerated liquid water and give it food like molasses of course it's going to grow you know; any kind of bacteria is going to grow but that’s what I thought was very flawed with it and it actually you know in people's minds became so serious that I think it was what's the organic branch of U.S.D.A. called? (NOP) Yeah, when they had the compost tea council's part of that and because of those lab results they said you shouldn't use molasses in compost tea out of all this fear mongering about e. coli growing and so it's just that a lot of people are saying never use it because of that and it's just in my mind just a kind of a silly knee-jerk reaction. And as you know all you know it feeds fungi just as well as it does bacteria so it's a very useful food stock to use.

Tad: Yeah I would say that's one of the myths that you sort of help dispel or challenge over the last decade. Another one is foaming. I know when I first got in the industry everyone was talking about how you need to have a good head of foam on your compost tea like it was a beer or something. You were able to show from looking under the microscope that that really wasn't the case?

Tim: yeah well those things are still rampantly running growing by rumor everywhere and constantly I have to keep repeating but it doesn't necessarily mean anything but...

Tad: I don't want to keep you for too much longer here Tim, really appreciate you taking the time today and maybe we can do a follow up interview to kind of hash out some more of these topics here in the future.

Thanks Tim, don’t forget to check out Tim's website for more information, microscope videos and images. He is inventor of the fifty gallon Microbulator and the five gallon mini Microbulator, both currently available on He also has a microbe identification D.V.D. that helps farmers in identifying various microbes under the microscope; available only on his website for forty dollars. This D.V.D. was very helpful to me because microbes don't hold still on the slides so it's much more useful to see video than still images. You can also read more about Tim’s theories and research regarding root exudates at, a free forum hosted by Tim and myself. You're listening to the Cannabis cCultivation and Science Podcast; I'm your host, Tad Hussey stay tuned for future podcast from leading experts around the industry and don't forget to check out our blog at And if you enjoy these podcasts, please take a moment to leave me a review on iTunes and send me your feedback and suggestions through our website contact page.