What is a soil factory?
A soil factory is a place where you produce high quality nutrient rich soil. It’s your go-to place for compost and potting soils. It’s just like your bag of shop-bought compost but it’s home made and you know exactly what has gone into it!
How will a soil factory help in my garden?
A soil factory provides a great place to put your bokashi pre-compost throughout the year but can be especially useful during the winter and summer months. During the winter my ground is often too frozen and hard to dig a trench to bury my pre-compost. My soil factory provides a great place to put my pre-compost and serves as a great source of fantastic compost when spring comes around. During the summer months I like to use every possible space to grow fruits, veggies and flowers and it can be hard to find a spot to bury my pre-compost. So, once again, I turn to my soil factory for my bokashi pre-compost. I then simply go back to my soil factory whenever I need compost. Its really just like a small, portable, low-maintenance compost pile.
How to make a soil factory?
Making a soil factory is easy. There are a number of different methods for making a soil factory. Below are three of the methods we have found to be successful (in no particular order); using a container, using two (or more) compost bays or burying in the ground.
Method 1: Using a container
This method works well if space is fairly limited or you only need a small amount of compost.
Step 1. Find container
Find yourself a large plastic box with a lid. Drill a few holes in the bottom to let liquids escape. If your soil factory will be positioned on impermeable ground (such as a patio, garage or balcony), then do not drill holes in the bottom.
Step 2: Add garden soil
Next, put 3-4 inches of regular garden soil at the bottom of the container. *Tip* Try to use healthy soil with lots of life in it. The more worms and grubs the better!
Step 3: Add your bokashi pre-compost
Then you are ready to add your bokashi pre-compost. Empty the contents of your fermented bokashi kitchen composter to the container, making sure to break up any large lumps of pre-compost. Add another couple of inches of regular garden soil and mix slightly with a garden shovel.
Step 4: Add more garden soil
Add a few more inches of regular garden soil and place the lid on the container. The final mix of soil : bokashi pre-compost : soil should be about a third, a third, a third. The depth of each will obviously depend on the size and dimensions of your soil factory.
Put a couple of stones on the lid to weigh it down, if needed.
Step 5: Wait
Leave for 2-4 weeks and check your soil factory. It may take slightly longer for your pre-compost to break down in your soil factory than when using the trench method as there are fewer worms and other soil biota in your soil factory. Colder temperatures may also slow down the process too. You can speed the process up by mixing the contents of your soil factory every week or so. Be patient, the pre-compost will break down and you will have a soil factory full of great compost.
Step 6: Use compost or add more pre-compost
Feel free to add more pre-compost to the top of your soil factory. Remember to mix the contents each time after adding. Remove compost as needed. Remember, if you expect to need compost within 2-4 weeks, don’t add any fresh pre-compost to your soil factory. If you want a regular place to put your pre-compost and a place to constantly get compost then we would recommend setting up two soil factories.
Method 2: Using two (or more) compost bays
This is a great method if you have a small unused corner of your garden that you can set aside for your bokashi soil factory.
Step 1: Build a compost bay
This approach looks similar to a more traditional compost set-up. Build two, or three, boxes (similar to the one shown in the photo). The first box will contain garden soil, the second box will be used to layer your bokashi pre-compost and the third box (if using a third) will contain the finished compost.
These boxes should be covered to protect from the rain and should allow good airflow. The size of these boxes will depend on the amount of bokashi pre-compost your household produces and the amount of compost that you hope to create. They don’t need to be as large as a traditional compost pile as they will only be used for adding your bokashi’d food waste. 1 to 1.5 metre cubed boxes should be sufficient for most households.
Step 2: Collect garden soil
Collect some garden soil for the first box. You can add soil to this box whenever you have some old soil that needs a boost. For example, from planters and containers that need replanting.
Step 3: Add your bokashi pre-compost
Add your bokashi pre-compost to the second box. Then add a couple of inches of garden soil from the first box and mix well. Finally, add a couple more inches of garden soil from the first box.
Step 4: Repeat
Repeat steps 2 and 3 until your box is full. If you are using the three box method, you can then start layering the bokashi pre-compost and garden soil in the third box. If you are using the two box method, you should harvest your compost to make space in your box to add more bokashi pre-compost (see step 6).
Step 6: Harvesting your compost
If you are using the three bin method then harvesting your compost is simple. Once your second box is full, simply leave it for 2-4 weeks for the final bokashi pre-compost to break down. You are then ready to collect and use your finished compost as and when you need it.
If you are using the two box method. You will need to collect your finished compost from the bottom of your box. There are various ways that you can do this, but here are a few suggestions to get you started. (1) Design your box to allow access at the bottom of the box so that you can dig and remove the finished compost. (2) Don’t add bokashi pre-compost for a few weeks so that the most recent layer of bokashi pre-compost has time to fully break down. (3) Move the top layers of bokashi pre-compost to one side so that you can access the lower (finished) compost.
Method 3: Burying in the soil
Making a soil factory in the soil is really a combination of the above container soil factory and the regular trench method for burying your pre-compost.
Step 1: Choose an area
Firstly, choose an area in your garden that you don’t need for planting in the coming months.
Step 2: Bury your pre-compost
Next, use the trench method to bury your pre-compost. Rather than planting directly into this area, use this area for collecting compost to be used on the rest of your garden.
Step 3: Make a grid pattern
You can set up a grid pattern if the area is large enough. Add pre-compost in rotation to 3-4 areas in your soil factory area. This gives you a regular place to bury your pre-compost and a constant supply of compost. It also has the added benefit that you don’t need to plan your planting schedule around when your pre-compost will need to be buried.