How to add microbes to your soil



Recently, we decided that for weed control, we were going to solarize our garden beds through the hottest part of the summer.

But, as our research showed, there’s a drawback to solarzing beds: The heat and UV radiation kills beneficial microbes in the soil.

So, I’ve been doing research on how to add microbes back into the soil in order to get better results for our Fall garden.

Some of these methods are well researched, others, however, are random, barely researched ideas, and should be taken with a grain of salt. I’ll start with the researched topics first:


Earthworms are hands down one of the best ways to improve your soil. These wiggly, slimy powerhouses work really hard to ingest organic material, including fungus and other microbes, and produce worm castings (a.k.a. worm poop) that is rich in microbial activity. In the process, their movement through the soil aerates the soil and breaks down the organic matter into humus, which provides a home for microbes and helps retain nutrients and water in the soil. If you don’t have any earthworms, get some. You can buy a worm bin here (we’ll also be doing a blog post soon on turning an old bathtub into a worm bed).. We’ll be digging earthworms out of the forest floor on the edge of our property. But, you can also add earthworm castings to your soil to get some of the same benefits.

2. Compost

Compost is chock-a-block full of microbes, most of which can be beneficial. As compost breaks down, bacteria and fungus “eats” the organic material in compost, making the nitrogen, phosphorous and potassium (NPK) available for use by plants. While there’s an important distinction between soil and compost (soil is an aggregate material while finished compost is primarily humus — aka broken down organic matter), for the most part, finished compost can be used as soil and as a soil amendment. The bacterial and fungal materials that work to break down compost have benefits to your soil: Earthworms and other organisms consume them and work in conjunction with them to improve your soil. Soil containing compost and other organic matter “holds” on to nutrients plants need better and require less water over time. If you haven’t started composting yet, do it now. Here’s all the information you need to know. If you have an HOA, you might want to invest in a commercial compost bin. Otherwise, build one with what you have lying around. In the meantime, get some compost tea and add it to the soil.

3. Innoculants

Soil inoculates, applied to seeds or directly to the soil, take the problem of adding microbes to your growing medium on directly: Need microbes=Add microbes. Commercial soil inoculates are used to add beneficial bacteria and fungus to soils which hopefully provide a method for nutrients in the soil to be made more readily available to plants. You can also apply them to seeds before planting them, in order to create a “zone” around the root structures of your plants. Both methods work, but scientists often disagree on why, how or how much.


The methods below are collected from various and assorted forums, conversations and experiences through the years. I have no idea if they’ll work or not, but there’s anecdotal evidence that suggests they might. A couple of them are just random guesses and thoughts.


Beer was suggested as a soil amendment when I found out about Terra Preta. After reading about this magical material, I googled around to see if anyone had attempted to recreate the soil. This was the only recipe I found. The recipe suggested using beer to add yeast to the soil. Another google search brought up this forum thread for cannabis growers who claimed beer worked really well for all sorts of things. It’s worth trying, because beer is cheap. I figure I’ll buy a 40 oz. beer from my local gas station, mix it with a gallon or two of water and put it in my sprayer.

2.Fermented Rice Water

About two years ago, as a member of the Onslow County Farm Incubator Program, we hosted a group of Mexican Agricultural college students visiting. The group was part of a class of Mayan Indians from the Yucatán Peninsula. While there, I was discussing, with my incredibly limited remembrance of high school Spanish and with the help of a Panamanian-born extension agent, the difficulties we were having dealing with Curcubit Downy Mildew. An agronomist with the group said they used in their Milpa farms in the region, fermented rice water to combat the problem.

Essentially, farmers there cooked rice, and buried it in the ground in a small, two-three foot deep hole in the ground lined with leaves to hold the water in.  I cannot, for the life of me, remember if the opening was covered with more leaves or had a mesh screen over it or not? According to her instructions, after a few days, get the water out of the ground and strain it. Then use the material, a cup per gallon of water, to spray down your plants. So, of course, straight to google I go. I found this recipe for a similar product, but I honestly don’t know if it’s the same thing. Check it out. Either way, I’m going to try it out and see what happens.

3. Kefir, yoghurt and sauerkraut juice

I have no idea, or reason, to believe this will actually do anything. But, I figure all three things have live, bacterial cultures; are readily available and I doubt can do any serious damage, so why not? Again, I’ll cut these with water and spray the soil down with the mixtures. Wish me luck!

My plan:

I’m going to solarize my soil until the middle of August. While that’s happening, I’ve surrounded the clear plastic covering my beds with mulch (composed of leaves and wood chips). While waiting for the soil to solarize, I’ll spray that mulch down with beer, fermented rice water, kefir, diluted yogurt, sauerkraut juice and innoculants. I’ll also spray down the mulch with Neptune’s Harvest Fish and Seaweed Fertilizer, to provide nutrients to help break down the mulch. After August, when I pull up the plastic, I’ll mix the mulch in with the soil and add manure, compost, compost tea and earthworms and earthworm castings from my worm bed. Then I’ll begin my Fall garden at the end of August. What are your thoughts? Do you think this grand experiment will produce results? Let me know in the comments.

Share the LOVE...

Melissa has a background in marketing, brand management, graphic design and photography. She left corporate America to pursue her dream of living a simpler life. Simpler doesn’t always mean easier but she enjoys every minute on her small homestead. She loves to cook, practice herbalism and gardening. Her passion is spreading the word about sustainable living and sharing her love of herbalism and living from scratch.

Click Here to Leave a Comment Below 0 comments

Leave a Reply: