We’ve started putting in raised garden boxes, where a lot of our cold weather crops will be grown, with a transition into summer crops, and I wanted to quickly share the gardening technique we’re experimenting with this year. It’s called the Core Method, and its not necessarily a new technique. But this is the first year we’ve used it in our own garden.
The method is simple. The idea is to incorporate organic material down the core, or center, of your raised bed before planting. As this material breaks down it will release vital nutrients to your plants while enriching the soil and raising the moisture retention ability in your soil bed. Most of the time this is done with rotted straw, but we’re using rotted grass clippings and mulched leaves.
We have this great space in front of the old brick barn, nestled on the southern side of the hog shed, where the ground is relatively flat. This picture was taken yesterday late afternoon, but we get at least 8 hours of direct sunlight here, and the hog shed provides decent wind break. Our plan is to put in nine raised beds this year, and to incorporate some flowers throughout the space to attract those necessary pollinators.
Once the box is built and placed, I’m laying cardboard on the bottom, right over the grass. The cardboard will kill the grass and act as a weed barrier.
After the cardboard is placed and soaked really good, I’m putting down a thin layer of mulched leaves from our fall pile. Then I’m placing the rotted grass clippings right down the middle of the bed in clumps about six inches deep. The grass is rotting but still green, so it should be a nice source of nitrogen for my spring crop.
Many people use straw instead of grass clippings. I don’t currently have access to straw, so I’m using what I have readily available. The important thing to remember is that whether you use straw or grass, it should be partially rotted already. Don’t use it if its wet and slimy, as this will work against the balance you’re trying to create in the soil (think composting; same principle), and could contribute to plant disease or hinder growth. You don’t want to use fresh straw either, as you might not see the benefit of it breaking down until the following year. Using material that is already in the process of breaking down will give your plants a continued source of nutrients throughout the season.
After the grass clippings are placed, I’m adding native soil from the property. Our soil here is a rich blend of sandy clay and I want to use it as much as possible. We had a new septic tank put in last summer, and after the leech field was excavated we ended up with a large pile of black earth. This is what I’m using to fill our boxes.
I’m starting at the sides and spreading the native soil throughout the box. I’ll cover the grass and mulched leaves and then follow with a layer of compost, which we’re having trucked in from a local business within the week. Once I add compost, I’ll mix in more native soil. Then I’ll be ready to plant.
Remember, good soil is the key to growing healthy plants! Building up the organic matter in your garden soil will attract worms (that’s why we don’t put landscape fabric underneath our raised beds), improve soil structure and as the grass breaks down it will create a beautiful humus.
By the way, you don’t need to have raised beds to incorporate the Core Gardening Method. If you already have or are establishing raised beds on the ground, whether permanent or annual, you can use this method to enrich your soil. This is a neat and organic way to let nature do the work for you, and works well on a no-till garden plot!
I’ve never heard of the Core method before, thank you so much for sharing!
I love the raised beds you have made too.
Thank you! If you end up trying the Core Method, you’ll have to share you’re results and let me know if it worked for you.
How did this work out for you? Is there a followup post to read?
It worked out really well for us. The grass clippings broke down well over the season. We started spinach, lettuce, carrots and radish in the boxes and then followed up with peppers, broccoli and brussel sprouts. Didn’t need to add much to supplement nutrients in the soil in between.
Thanks for the insight.
I am just learning about core.
It seems to share much with hugelculture. Both increase soil aeration thereby benefiting healthy root systems, symbiotic bacteria and fungi for nutrient uptake, even water distribution, and water reservoir.
It would seem to me that getting the balance right between water dynamics and aeration is critically dependent on
– rainfall (high/low, seasonality)
– atmospheric water content (humidity)
– underlying soil quality (high clay or sand).
– Long periods without rain would likely benefit from a water sink below natural ground level. If it is above, then gravity will pull the water away from the water sink.
– If rainfall is high, then the sink would benefit from being above natural ground level, otherwise it will hold excess water, and starve organic material of oxygen.
I think an advantage of hugelculture is you can build very high mounds. In Europe, they can be 8-10 foot high with steep sides, thereby reducing the need to bend, and getting more dense productivity per square meter.
Thanks for your insights again.