Soil Science: UN-Blowing Your Mind Part 2—Compost and Its Extracts and Teas

Dr. Elaine Ingham wrote The Compost Tea Brewing Manual. Its comprehensive. It is also out of print and has a copyright. I don’t want to violate that copyright or the guidelines of this forum so I’ll leave you on your own to find a copy.

@Jeff you noted in the Q & A that Ryan wasn’t seeing results with his use of an extract. It may that it’s too soon to see results because:

  1. There is seasonality to plants. Dr. Ingham touches upon this in the podcasts from Part 1. Applying a drench in mid-summer, as Ryan did, when a tree isn’t actively growing much may not be the best time. The results make not be visible until seeing the spring growth next year or when repotting.

Jeff Lowenfels, an award-winning gardening writer and another Dr. Ingham acolyte, recommends in his book Teaming with Microbes, that in a yard apply a drench two weeks before leaf out and after leaf fall. He also recommends using a tea to spray the leaves when they appear. The same timing reasoning may apply to container plants protected from freezing. (Teaming with Microbes is an informative book and so is his Teaming with Fungi . Both should be available at your local library.)

  1. Ryan said he used a more diluted extract than is usual to be safe. Because the drench was applied to bonsai soil, lots of the microbes, from what was already a lower-density tea, drained out of pot with the water. The dilution factor of an extract needed for bonsai soil is something that hopefully Ian is somehow studying. Did Ryan say that he was seeing detrimental signs?

  2. The compost used in the extract came from the foothills of the Sierra Nevada mountains in California rather than locally. It will have had lots of different microbes that may not do well for life in a pot in Oregon. Dr. Ingham discusses the importance of using locally sourced compost in this podcast:

Compost, Compost Tea and the Soil Food Web. Joe Gardener Episode 117

Use of a drench or tea is to improve the soil and foliar biology. This will increase nutrient availability to the tree, which will make the tree healthier. Some proof of success may be that the tree isn’t showing signs of stress and disease and pest infestation. Pests and diseases know when a tree is sickly and weak. The bad ones will just move in on that compromised immune system because it’ll be buffet time for those vultures of the plant world.

Drenches and teas can take time to see results and can vary by the plant and original condition of the soil. A great example of this in this very short (80 seconds) video by Dr Ingham. (For those of you that live in Oregon like me, you can see the humor of it because we know what she’s talking about.)

Quiz Time with Dr. Elaine Ingham. Which has compost tea?

@Michael_P , you talked about fermented teas. These are anerobic, bacterially dominant potions that may include the “bad guy” bacteria. They may work somewhat on your annuals, which are more bacterially oriented, but our trees should only have aerobic, fungally dominate extracts and teas. An anerobic tea may seriously harm or kill a tree.

Bare dirt is bacterially dominated with a lot of those being the “bad guys.” As plants establish themselves through what’s called plant succession—“weeds;” annuals and grasses; perennials; shrubs; softwood trees; and then old growth, hardwood trees—the biology changes from bacterially dominant to more fungal. The soil pH also goes from more alkaline to more acidic. Google “plant succession stages” for more on the subject to see some images that illustrate the succession.

@BillsBayou , you mentioned growing cannabis. It is an annual. What works on your crop may not be best for your trees for the same reason. Pot growers often use molasses, cane sugar, or other sugar source in their aerobic compost teas. The sugar increases the bacteria count in the tea, which is why compost tea recipes that are intended to be fungally dominant do not contain any sugar. On your podcast app search for “Cannabis Cultivation Jeff Lowenfels episode 2” to hear him talk about mycorrhizal fungus and compost teas. He’s a fellow grower with a great sense of humor.

Back to the molasses issue. In her brewing manual she talks about using it. Now she is very specific in wanting you to know why you are using on a particular plant before you do so. She talks about this in this short video:

Elaine Ingham on Molasses in Your Compost Tea

She also mentions using fish hydrolysate with chitin in the video. Fish hydrolysate with the chitin is sometimes called “oceanic hydrolysate.” The chitin comes from the shells of shrimp and crab. Chitin improves the autoimmune system of a plant and strengthens its cell structure. For a pathogenic organism coming along to feed, it can be like the difference between biting into and apple and a cantaloupe. Don’t go overboard in its use. Too much chitin can reduce the nematode population because the same enzymes that digest the chitin also digest the shells of nematode eggs. Shrimp and crab meals are used as a “natural” control for root-feeding nematodes. Unfortunately, they will affect the beneficial nematodes too.

I’ve started adding small amounts of crab and shrimp meals to my compost for the chitin boost. You can add the crab and shrimp shells from your dinner if you want. Along with keeping track of the nematodes in the pile, I’m keeping an eye on the beneficial insects in the pile, like sow bugs and mites, too. If the chitin-eating bacteria get to too high in number they will eat away at their outsides. Their exoskeletons are made from chitin. Chitin-eating bacteria are sometimes used to control insects.

FYI #1: In the last Asymmetry podcast they talked about the 400-micron bag used for doing a compost extract. The company that makes the five-gallon paint strainers from an Ace Hardware, Lowes, or Home Depot says they are 600 microns. It works fine though its openings are slightly bigger. Turn it inside out so the compost doesn’t get hung up in the seams. It’s easier to clean that way. Dr. Ingham recommends using one cup of compost for each 12 cups of water when doing the extract. Massage gently for a 3 to 5 minutes. For small extract batches and teas, a one-gallon paint strainer bag will work.

FYI #2: Dr. Ingham’s method of doing a bucket tea in her brewing manual is out of fashion. You can google “five-gallon compost tea brewer” and click on the images to get an idea of how they look and where you can buy an entire kit if you’re not handy or don’t want to mess with making your own. Here’s a picture of mine:

In addition to having air come from the bottom spiral, I have air going into the bag from the top piping. The pipe also serves as an easy way to hang the bag. Dry fit all the connections rather than glue because you will need to take brewer apart for cleaning after each use. A spring clamp used for hanging tool handles is screwed to the side to hold the brewer in place. Make sure you turn your pump on before putting the piping in the water and don’t turn it off until after you take it out; otherwise, water will pour into the piping. I spliced in an on-off rocker switch into the power cord of my pump for convenience. (WARNING: The pump is loud.) Cut a slot in the bucket lid to fit around the piping to contain the occasional splashing.

And yes, I now look at my compost and compost teas and extracts with a microscope. It’s fascinating and informative. Water bears and nematodes are cool to watch. I can also tell that my newer compost pile that I’m trying to make fungally dominate is because of the number of testate amoebae, fungal hyphae, and fungal spores I see.

The term fermented tea may not be the correct one, non-native speaker here :slight_smile: In French it’s called “Purin d’ortie” (nettle manure) or “extrait fermenté d’ortie” (nettle fermented extract). Nettle manure/nettle extract works through initial fermentation of the nettle leaves and stalks (2 lbs) in rain water (9 quarts). The fermentation is extremely quick, depending on the ambient temperature (5 days at 86F, 15 days at 68F, 20/25 days at 50F). You just want to keep insects out, so a towel or mosquito net on top is a good idea and you need to stir it at least daily. As soon as the initial fermentation is done (no more foaming/bubbling), the solids and liquid need to be separated. The solids still can act as a compost activator but would decay into a sludge if left longer in the liquid. If not used with a few days, the liquid needs to be stored away from sunlight in a non-metallic airtight container… it will keep up to 12 months in the basement.

The liquid can be used as follows:

  • Diluted at 5% for foliar spray misting every 5 to 10 days, only if the plant is well watered
  • Diluted at 10% applied with watering can as a fertilizer
  • Diluted at 20% applied with watering can as a bottom manure for field growing
  • Diluted at 20% sprayed against white powdery mildew or insects

I’ve used nettle tea on trees consistently for three years without issues (and for several years before that, in a more random application), both in the ground and in pots. Trees and shrubs treated with it display stronger growth and better resistance to disease/pests than the ones that weren’t. Maybe I should do (and document) a nice double experiment with rooted cuttings (juniper, cotoneaster, cherry) next year, showing the difference over three years.

Rolf Paterson research on nettle water


Not the direction I was leaning in the conversation. I don’t have any crops to worry about.

Thanks @Ace
Some real gold in there!
I, like many others have issues with root aphids. I realise that the probable cause is that I have probably weakened my trees with poor water/ oxygen balance in my watering technique, but wonder if a bare rooted tree at repot time would benefit from being dipped in a compost tea? My thinking is that the microbes would have a chance to stick to the whole plant, roots and all, after aphids have been washed off. I also grow alpine plant which get hit with root aphid.

@AndyK, after learning about the damage tilling soil does to the microorganisms and fungi, I decided never to bare root a tree again. Rather, I’m going to leave some soil to help protect as much of the rhizosphere as possible. I’m also going to do a compost extract soil drench of a newly repotted tree to get some microbes and fungi into the new soil particles to better make them a hospitable place for new roots.

A few years ago in the BSOP meeting where Ryan was explaining the organophosphate root drench he did to kill his root aphids that ended up burning his roots, he then recommended using beneficial nematodes as the first choice to control root aphids and Bt (Bacillus thuringiensis) as the second.

The “beneficial” nematodes are actually predatory nematodes and will be like the alien in Alien to the chest of a root aphid. They are sold as nematodes Hb and Sf (Heterohabditis bacteriophora and Steinernema feltial). For root aphids, the companies that sell them recommend to use a mix of the two.

Here’s a real informative article that explains root aphids and several recommended controls. However, its recommended use of a insecticidal root drench is warned against in another article I read. Any chemical used will also kill beneficial organisms and fungi too so be careful.

Root Aphids and Controlling Them

Thanks @Ace
I have killed too many plants trying to get rid of root aphids. In fact, more plants than I would have if I had done nothing at all. I have started to accept that they are there and not get too freaked out when I see them. That being said, I am keen to keep them under control. Will definitely go for compost extract after repot and look into nematodes.