Direct Composting – Soil Overwintering
Soil health is your top priority when growing plants, especially ones you are going to eat. In the image above you can see the back blue raised bed is being direct composted, I cover with cardboard to keep the critters out. If you have been gardening more than a year in most areas you are going to need compost. Even in rich Iowa and Illinois dirt you have to give back as much as you are taking or your plant size and health will suffer.
Direct composting has always been the easiest and best method to get nutrients back into your soil fast. When I lived in a place with cold winters I would call this method “overwintering” but now that I live in normally 80+ degree weather most of the year I call this in-ground composting or direct composting.
When I realized you could use over wintering methods in the tropical garden to make compost directly in the bed, I was thrilled. No more buggy compost piles and weekly turning (or at least a lot less of it.) While I do a lot of direct composting now it really only works when you clear a bed for dormant period or between your season planting. 80% of my garden happens to be between MILPA and winter food crops during October and November and it’s a perfect time to direct compost.
Those reading in winter weather places may also find October or November is the right time to overwinter their bed. If you don’t have snow on the ground right now and the top soil isn’t completely frozen, you can use this method to enrich your soil for next year.
What you need
Lots of fresh (or frozen) organic material
An empty garden bed
A lot of mulch, wood chips, leaves or other dry material
Step 0: (optional) 1-2 weeks before starting direct compost chop and remove all the existing plant matter in the bed.
Lay these stalks, stems, leaves and other materials over the soil in your bed. As they decompose they will attack the bugs and worms to the top of the soil and promote soil health. You will remove any of this material that remains in sep 1 or work it into the soil.
Remove any large or study debris and stalks from your selected garden bed.
You can leave any mulch or small dried plants.
With a shovel or other garden tool stab the ground to break up the small debris and soil, this is a light till you don’t have to work the soil up completely and it is better if you leave any roots intact because they help hold your soil together and prevent erosion and soil loss. This is especially helpful where I live in the rocky and rainy Yucatan where soil can quickly wash way, but true everywhere.
Step 3: (choose either method A or B)
Method A: This method is good for shallow beds, hard and/or rocky soil.
Cover the entire area with fresh organic material, and break up a bit with the shovel by piercing from above. This should move the organic material into the soil but not till up too many of the roots. (continue to step 4)
Method B: This method is good for deep raised beds or areas with light and loamy soil
Dig a hole in the soil about 6 inches to 1 foot deep depending on how hard the ground is or how deep your raised bed. If you start pulling up rocks, stop digging. Fill in the hole with organic material. Cover the organic material completely with a layer of 2-4 inches of dirt. (Continue to step 4)
Step 4: (for both methods)
Cover the fresh organic layer well with mulch, untreated wood chips, or other dry material. You want to cover the organic material completely so that no flies or mosquitoes are attracted. Cover the mulch with cardboard and weight down with rocks or blocks.
Extra Useful Notes:
The cardboard helps the decomposition especially in overwintering because it protects the bugs and worms with insulation, sunscreen and a bird shield. They can focus on working.
In the tropics it also deters cats and other digging pests from making a mess. I’ve found the cardboard also helps limit volunteer plants and weeds while you are waiting for the bed to be ready.
In direct composting where I live, the beds are ready to use in 3-4 weeks. I usually prepare the beds using this method after harvesting MILPA and direct compost an area every two weeks or as I have enough organic material. Seeds take about 4-6 weeks to be ready to transplant meaning the beds are always full of nutrients when the seedlings need them most. The rest of the year I don’t have empty beds and I use this urban composting method to add nutrition to trees, container plants and even used bed spaces when I plant a seedling directly after cutting out an older plant.
In overwintering all the organic material and most of the cardboard will be broken down by the time your soil warms up in the spring. Your mulch layer will likely still be there, but make sure you add more after you lightly till the soil and plant your seedlings.
Unrelated Notes on Tilling Soil:
I haven’t written a post but I mentiond it above, my recommendation is to only till your soil lightly with a shovel to break it up and make it possible to plant, you do not have to completely turn over your soil each spring. When you do this you destroy complicated root structures that help hold your soil together, add nutrients and prevent erosion and soil loss.