View Full Version : Compost Tea

09-02-2003, 11:42 PM
Has anyone used compost tea? Just began using this summer saw limited results.

09-03-2003, 02:03 AM
First of all, what is compost tea? Secondly, why would you use it?

Compost tea could be several things. The simplest version is to take a container of water, dump a load of compost in it, and let it sit for a couple days. The idea is to let the microbes in the soil leach out into the water so you can spray it on rather than spreading it out.

The next step up is to add some microbial nutrients to that first tea. There are as many recipes as there are people brewing it, but here's the basic idea. Microbes need proteins and sugars to thrive. The standard protein in scientific laboratories has always been a form of seaweed called agar agar (or just agar). So seaweed is always a good thing to use to grow microbes. Then a blast of molasses makes the sugar for it. Water temperature changes the recipes because microbes will multiply faster or slower depending on temp and sugar content. Using too much sugar at high temperatures can kill off the beneficial microbes you're trying to grow.

The next step up is to aerate the tea. Microbes need air to survive. For small batches you can use an aquarium pump with a couple aquarium air stones to form a wall of bubbles in the tea. The bubbles provide extra air for the beneficial microbes to breed in and it also kills off the pathogenic microbes that must live where there is no air. Some professional aerated tea brewers claim to multiply the original microbial count (from the original dose of compost) by a factor of 1,000 or more. What this means is that instead of buying 43 cubic yards of compost for an acre of turf, you can instead use one gallon of compost in a 5-gallon tea brewer. Plus when you're finished making the tea, you can recycle the used up compost in your compost pile. It sounds like perpetual motion but it does all disappear eventually.

The final step is to add agitation to the aerated brew above. Only the professional tea brewers have pumps hefty enough to actually agitate large quantities of tea. The reason for agitation is to dislodge the microbes from the ingredients so that more microbes can have a chance to grow there.

Professional compost tea brewers can be had with capacities up to 100 gallons - maybe more. They go on at a rate of 5 gallons per acre. Spraying compost tea is becoming a niche market. The tea must be used right away when it is made. You cannot store it because it is full of living microbes. When they die, they stink, BIGTIME. If you try to cap them off, they seem to generate internal pressures inside the container that will burst some weaker containers.

Now why would you use compost tea? First of all you have to believe that there are trillions of microbes in a cup of normal healthy soil. In normal soil the balance is toward beneficial microbes. If you run into a soil that has had some chemical damage or is otherwise lacking in a full complement of microbes, then spreading compost or spraying compost tea is a good idea to restore the beneficial microbial species to the soil. Then if you also believe that there are many many layers of microbes living outside the plant on the surface of the leaves, stalks, stems, and flowers; then you should understand that foliar spraying of compost tea is also a good idea to replenish those microbes.

Now y'all can proceed with the discussion about whether anyone has used tea in the business and what were your results?

09-03-2003, 03:39 AM
I have a few customers use it. I have gone to applying microbes and enzymes that I mix up myself. They've developed a process to dry the microbes in powder form. A pound will cover 1 acre.

09-03-2003, 12:12 PM
An interesting subject. I have not yet experimented with it. For the time being, I seem to be more interested in the simpler approach of just apply compost. Someday I'll mess with the tea. I would think just plain compost would be more appropriate for lawns and the tea would be more useful for specific problems in gardening, like spraying on leaves for certain diseases, etc.

Mike McGrath is way into it. He was the editor of Organic Gardening Magazine back when it was good, and currently does a radio show called 'You Bet Your Garden". Its a very fun and informative show - worth looking for - its on the local NPR station here. More info is here:
I thought he had info on compost tea there on the Tips page but the website seems to be broken right now - all the menu links are going to the same page.

Howard Garrett, "the Dirt Doctor" is way into it too. Here is a bit of info on it from his website:
Tons of organic info there. Main page is:

A friend of mine drinks 3 glasses a day and man is he healthy! :laugh:

09-03-2003, 12:32 PM
Farmers like tea because they can buy all the equipment and materials at retail, and make tea for much less than buying enough compost for a few acres. Tea costs 1,000 times less than compost on a per square foot basis.

Plus farmers can consult with the expert, Dr Elaine Ingham, and she will give them a recipe specifically for their crop. West coast grape growers are apparently going crazy over compost tea.

You can read more about compost tea from THE guru, Dr Elaine Ingham, at


If you decide to sell a tea you make yourself, eventually the buyers will be savvy enough to ask you if it has any microbes in it. There are a few simple things you can do wrong to give you a net result of zero microbes after all that brewing. Dr Ingham offers a testing service to check your processes and make sure you are delivering the product you are offering. Of course the testing becomes part of the overhead in your compost tea profit center ;)

Compost tea is a source of beneficial microbes. Do you need an applicator's license to apply microbes? These microbes do not directly fertilize (no NPK) or protect the plants (no direct killers), but after they have done their jobs, the plants become healthier and more disease and pest resistant.

09-03-2003, 11:24 PM
I was experimenting with the microbe product I use as a root dip on some grape cuttings (they advertise as it also can be used for this purpose). Most of the cuttings were dipped and about 25 weren't. Both groups were placed in native soil amended with planting compost. The dipped cuttings have three times the growth and are fuller and healthier.

Some tests by the manufacturer show vineyards producing an above average crop in only three years.

09-04-2003, 12:39 AM
Dr. Ingham is the reason I got into organics. Never thought much about it until I went one of her presentations. I use compost tea because I Deal with large properies and athletic fields, And it kills two birds with one stone ( helps prevent disesase& fungus, fert. alternative) It is more economical than topdressing w/compost.
I have a commercial brewer, and have built a larger one. Tea is a cinch to brew.

09-04-2003, 01:15 AM
I'm looking at lawn care, 2K to 25K properties, not farm fields or athletic fields.

If the object of organics is to improve the soil, and a proper organic soil is then host to microbes, why is it even necessary to consider adding microbes? You can't keep them away from a decent topsoil. A knee-jerk addition of microbes might just imbalance your growing medium.

Is organics really just another way for people to meddle with nature, rather than really understand and work in nature? A healthy growing turf will break up hardpan (from developer/builder sins) and will begin to create its own topsoil within a few years. No need to add anything - the growing and dying grass stems and roots provide all the organic matter needed. Lots of plant activity in a square foot of turf, if you look close.

09-04-2003, 01:36 AM
Here are some reasons to add microbes.

1. Flooding and/or standing water on a turf will choke off all the oxygen to the underlying soil and kill off all the fungi. Compost or compost tea will replenish the fungi species killed off and give them a head start as opposed to waiting for them to fly in on the feet of birds or grasshoppers.

2. The use of a fungicide on turf will kill off the target fungus as well as non-target fungi. Some of these non-targets are beneficials and are needed in the food chain for organic materials in the soil. Compost to the rescue again. Insecticide, herbicide, miticide, and even chemical fertilizers have similar effects to much different degrees.

3. When dad decides to build a tree house out of CCA lumber and does all his sawing in the middle of the yard, the sawdust will leave a bare spot there for, oh...going on about 5 years now. Year after year of compost treatments is just now starting to show results. Nothing grows there but the spot is getting smaller (at least in my own mind).

4. A fungus invades turf. The microbial balance is already out of whack. By adding corn meal, the balance can be returned.

5. You have a fire ant mound in your yard. Fire ants hate sugar for some or several unknown reasons. By pouring 3 ounces of molasses in a gallon of water on the mound, the ants leave in 24 hours. Every time? Apparently not, but it's well worth a try. Apparently the molasses stimulates a bacterial bloom that may taint their food, infect their food, or just maybe make them feel sticky :) We don't know yet - at least I don't know yet. Keeping a slight sugar balance in an area seems to keep fire ants out. And the sugar ants don't seem to pay any attention.

Is organics really just another way for people to meddle with nature, rather than really understand nature? A healthy growing turf will break up hardpan (from developer/builder sins) and will begin to create its own topsoil within a few years.Turf grass growing and maintenance is meddling with nature. Some of your clients want the meddling done with organic materials.

09-04-2003, 02:07 AM
But Dave, we're supposed to be thinking organic:

#1 - a rarity, for most. And microbes do return naturally.

#2 - if I'm organic, I never use a fungicide, so this is not possible.

#3 - again, a rarity.

#4 - hasn't it been stated that if you use organics, you won't get fungal infections.

#5 - OK, you have fire ants, but most of the country doesn't. And this step doesn't add microbes, but feeds the ones you already have.

So it really seems to me a true organic program wouldn't need microbe addition except on very rare occasions.

And I wouldn't define growing grass as meddling in nature. We are all instinctively drawn to plants and earth because we are from nature. Too many think they have to control nature to succeed, whether with chemicals or organics. I have learned to maintain weed grasses as turf because I noted that nature put them there and they did better than normal turf grasses in that specific location. That is what I mean when I say: Work in nature, not on it.

09-04-2003, 02:24 AM
Oops! I misunderstood. I though you were not thinking organic, so I took off my organic hat and put on my flameproof suit.

You are absolutely correct! Replenishment of microbes is a rare requirement. You may find clients asking for compost, but I maintain that they rarely need it. Those clients need just a dash of education about what compost is and is not versus what an organic fertilizer is.

The founder of our local composting giant, Garden-Ville, let slip once that he has only used compost on his own lawn twice in 30 years and the second time he didn't think he needed it. This guy has 400,000 cubic yards of it sitting on his property and doesn't use it. To me that speaks volumes about the need for it.

Now the question was about using compost tea. In your practice you might start offering an organic tea spray on a semi-weekly basis. I believe this could change the balance of microbial life on the plant surfaces and in the soil. I believe the balance will be tipped toward the beneficials, at least at first. But you won't find me doing a lot of suggesting that the pros start offering this as a regular service. Some will do it though because there is money in it.

09-04-2003, 12:05 PM
OK, Dave. I'm understanding that compost tea is a way to add microbes. But properly managed landscapes have plenty nuff microbes. So isn't it a little bit crooked for me to sell compost tea applications because the client thinks he needs "organic" plant care?

Perhaps you are meaning compost tea is a good recovery procedure, to start a new lawn or recover from a major soil life disaster?

09-05-2003, 02:22 AM
Yes tea is good and inexpensive for recovery from a disaster. We're on the same page. But I can show you people who will stand up with a Bible and swear it performs miracles when used semiweekly as a foliar spray.

Could it be crooked to offer routine spraying? What if the homeowner insists on spraying it and hires someone else to do it? Do you still feel good about that discussion?

Or more importantly, what if the homeowner brings up the subject and you stare at him like a slackjawed mule because you've never heard of it before? Anyone who has read this deep into this topic is much more informed on several sides of compost tea than someone out reading the other forums on this board. I'll bet some of the hundred or so readers have already done an Internet search and found all the tea equipment manufacturers.

09-05-2003, 03:18 AM
Sorry about that "crooked" question, Dave. That's just my eccentric principles. I quit one client because he wanted me to plant grass where I knew it wouldn't survive ($1.8K/yr account); I'm sure he got someone else to plant it. Quit another because she wanted me to shear shrubs that had obviously been properly pruned for years (only a $1.5K account); I'm sure she got someone else to shear them. Quit others and walked away from a lot of new ones who want to tell me how it is to be done. If they have all the knowledge about how to care for their plants, why don't they just do it? Or hire a wino to do it at 1/5th the cost of me doing it?

Can't justify throwing out a 20 year reputation of honesty and successful, simple cultural management of plants, just to make money on someone's whim of what (s)he thinks is right for the lawn. But if it is the right thing to do, I can sell it even if it costs 5x what others charge for the solution.

09-05-2003, 10:45 PM
Instant grits work well on fire ants also!
The workers take it down the mound and they eat it, as soon as they take on some water they swell up and die.

09-06-2003, 02:09 AM
Okay. Time to debunk. This happens all the time that someone will get this info and pass it on because of the inherent joy all of us familiar with fire ants would have in the visual imagery of their exploding bodies.

If instant grits works it is not because the ants explode. My understanding is that ants have to eat liquified food, not dried. That would keep them from eating dried grits without first wetting it.

I could put forth a theory as to why grits might work against fire ants. I would guess that the grits would change the bacterial and fungal balances in and around the fire ant mound such that they don't like it there anymore. The grits might end up poisoning their food supply, it might "smell bad" to them (ants communicate via chemical traces that we would call smells), or it might attack something else in their little underground world. But I'm only guessing.

09-06-2003, 02:40 AM
From UGA extension publication (<a href="http://www.ces.uga.edu/pubcd/b1068-w.html">Controlling Fire Ants in Urban Areas</a>):

"Another technique is the sprinkling of grits on fire ant mounds. The theory is that the ants will eat the grits, which will then swell and rupture the ants' stomachs. No scientific research supports this claim. In fact, only the last stage of the developing fire ant is known to ingest solid food. All other life stages feed only on liquids."

If one thinks a old wives tales have any veracity, try a Google. Google for "grits fire ants" gets 1800 hits, with plenty of university sites saying the same as above. Also plenty of DIY sites fostering the tale, LOL.

09-06-2003, 12:22 PM
:) I was wrong on the instant grits. We use Dixie Lily Grits.
It does work, why I do not know. I have been using it for a couple of months and you can watch the ant's take it in to the mound.
In a couple of days, no more ants.
Who knows how, it just works.

Green in Idaho
09-14-2003, 06:10 PM
I would most like use tea new organic programs for a kick-start.

As far as existing organic treatments it is much like taking a diet supplement. Any tea is not going to have a significant affect one way or another. But as long as you are watering, why not add a little fertilizer (very low levels) and the microbes and others are added bonus?

05-25-2004, 06:58 PM
Just looked up this thread on compost tea and found it informative. I am a contract sprayer and wonder about the imbalances I am creating when I use pesticides on the lawn or tree. I then also wonder if applying the tea would restore some of those imbalances and create a healthier plant environment, making the plant healthier and thus more able to fend off deseases and pests.
Looking for answers. I always got lots of questions. :)

Tim G
05-26-2004, 09:18 AM
I started brewing compost tea 2 years ago. I make about 100 gallons a week. Iím just experimenting would like to start a business in it one day. There are so many questions to answer. I spray about 15 yards for friends. So far I have had really good results. I also add other inputs to there lawn, corn gluten and kelp among other things. What impressed me the most last year, was the fact that I had really no harmful insects in my own yard. I never saw an aphid on my trees. I found one caterpillar and he looked lost. Maybe it was just the year, I donít really know, Iím thinking it was the tea that made the difference. I will find out more this year, Iíll keep a closer look on the neighborís trees and lawns.
It is a great benefit to the soil, no question, but I think offered as a foliar spray it is very beneficial.
Here where I live, in the summer it actually will rain 24-d. Keeps the weeds down. They tested ponds and birdbaths after a rain and there was trace amounts. I think the addition of healthy microbes is a good idea. The plants seem to love it. With out any doubt my apples were bigger and better than ever. Anyone who had a garden, I sprayed only half of it. You could see the difference. The tea side had bigger, healthier plants and vegetables.
I worked for fertilizer companies for quite a few years, all the free fertilizer I could use, and believe me I did. I had a very nice lawn. Without any doubt at this point in time, with an organic approch, it looks better than it ever has.