Minor Biofumigation at the Fertile Garden

One of the benefits of growing Mustard Greens as a cover crop is its ability to clean the soil when tilled into the ground. When tilled into the soil, the plant material decays. As it does so, it releases volatile gasses containing chemical compounds that fumigate the soil. The term for this kind of cleaning of the soil by growing brassicas, mustard greens or radishes is called “biofumigation”.

 

 

 

 

 

 

 

 

 

An essential component of biofumigation is to cover the plot as soon as possible after incorporating the chopped up plants into the soil. Instead of saturating the surrounding soil, the volatile gasses will dissipate if not properly covered. While using plastic is generally preferred, I decided to do what I could with a layer of paper and soil. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

After chopping up the plants, I covered the debris with packaging paper and a layer of a high-quality soil blend. I made sure to water it all in well. In the end, between the off-gassing and the paper, the end result did dramatically decrease the incidence of weeds in the garden this last spring.

Raising more than just Mustard Greens

I love supporting local wildlife with flowering plants. I also love seeing some insects on my plants. It lets me know that I the plants are healthy enough for other animals to consume. However, there comes a time when enough is enough.

 

 

 

 

 

 

 

 

 

 

 

 

That time came for me this last winter when my Mustard plants became the breeding ground for several dozen uninhibited harlequin bugs (not pictured). By the time I was able to get to the plot, the bugs had begun multiplying. In order to deter the adults to set up camp, I came back as soon as I could – at night – and chopped down all of the plants. This left a lot of residue, but given the proliferation of bugs and the potential for the Mustard to spread seed, it was wise for me to remove the plants as quickly as possible.

2023 Backyard Mustard Greens

This last winter I pretty impressed with how tall and lush the mustard greens in my garden grew. Especially considering that my garden has been suffering from the nearby trees and local fungi extracting the nutrients from the soil. Given how much it has been struggling in the summer, it was great to see it do so well over the winter.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

One nice thing about growing in your own backyard is that you can see when the flowers are blooming and cut them down long before their seedheads mature. Just by looking out my back window I could see how the plants were coming along and take care of them while they were still manageable.

Cover Crops in the Grape Harvest Bins

Every year I change what I am growing in my winter gardens. The majority of the time it is a cover crop. This last winter, I chose to grow out Mustard Greens. Mustard Greens are usually very good at cleaning the soil, though they don’t provide a lot of organic matter. At both of the gardens where I planted them, they grew a bit wispy. However, at the old chicken plot, they were a little more vigorous. Once I had taken the time to cut the plants down, I covered them with a high quality soil mix.

 

 

 

 

 

For the second garden, which had received a lot of city compost with excessive pathogenic bacteria, the results were nowhere near as good. The plants dithered and only grew a little. We tried planting buckwheat, but to no avail. So in the end, I planted some fava beans in some high quality compost. Those seemed to do very well and helped better prepare my garden for the summer crop

 

 

 

Winter Garden Biofumigation

Over the last winter, I decided that it was time to clean up the soil in the entire garden. While most people would have concerns with sterilizing soil, after growing cucumbers in my plot for years and years, I felt it was time to refresh the soil in the entire garden by sterilizing it.

 

 

 

 

 

 

I began by pulling down all of the summer crop that I was growing and clean up all the debris. Then I planted out a blend of mustard greens that have been specifically designed to be used for this purpose. After they grew for a while and were beginning to flower, I tilled them in to the soil and covered the area with soil with my potting soil, watered it in and covered the entire garden with black plastic. Then I waited 2-3 weeks. The next thing I did was remove the black plastic, and incorporate biological fungicides. Prior to growing the mustard greens I had noticed a large amount of fungus that was growing around the roots of some healthy plants. I decided to mine this fungus and refrigerate it until I was done with the biofumigation process. With the biofumigation process behind me, I incorporated the fungus along with the bacterial fungicides, then planted out the fava beans. To summarize, here are the steps to biofumagate your soil.

 

Measuring the width of the garden

 

 

 

 

 

Chopping down the mustard greens

 
 

1. Grow brassicas, mustard greens and/or spicy radishes (the more biomass, the better)

2. Till them in.

3. Water

4. Cover with plastic (as soon as possible after tilling) 

5. Remove plastic

6. Allow to gas off

7. Incorporate healthy bacteria and fungi

8. Grow a crop that helps to restore the soil.

 

 

 

 

 

 

Though the plants did relatively well to begin with, weeks of dry winter weather began taking their toll on the growing fava beans. At this time, the fava beans are just getting by with me watering them once every couple of weeks. The relatively rainy weather of Northern California that was common in my youth is gone. As water is life, the prior life that many of us have known for so long in this area has become at least threatened, if not a sweet memory. While we cannot the weather, we trust that blessings will flow as we continue to pray for rain.