Hugelkultur: the ultimate raised garden beds!
What is hugelkultur?
As the years pass, the deep soil of the raised bed becomes incredibly rich and loaded with soil life. As the wood shrinks, it makes more tiny air pockets – so your hugelkultur becomes self tilling. The first few years, the composting process will slightly warm the soil giving a slightly longer growing season in temperate and cold climates.
Hugelkultur raised garden beds in a nutshell:
- Grow a typical garden without irrigation or fertilization
- Has been demonstrated to work in deserts, as well as, backyards
- Use up rotting wood, twigs, branches, and even whole trees that would otherwise go to the dump or be burned
- It is pretty much nothing more than buried wood
- Can be flush with the ground, although raised garden beds are typically better
- Can start small, and be added to later
- Can always be small – although bigger is better
- You can save the world from global warming by doing carbon sequestration in your own back yard!
- Perfect for places that have had trees blown over by storms
- Recycling at its best!
Used for centuries in Eastern Europe and Germany, hugelkultur (in German hugelkultur translates roughly as “mound culture” or “hill culture”) is a gardening and farming technique whereby woody debris (fallen branches and/or logs) are used as a resource.
Often used in permaculture systems, hugelkultur allows gardeners and farmers to mimic the nutrient cycling found in a natural woodland to realize several benefits. Woody debris (and other detritus) that falls to the forest floor can readily become sponge-like, soaking up rainfall and releasing it slowly into the surrounding soil, thus making this moisture available to nearby plants. The forest limbs fall to the ground, rot, and produce life.
Hugelkultur garden beds (and hugelkultur ditches and swales) use the same principle to:
- Help retain moisture on site
- Build soil fertility
- Improve drainage
- Use woody debris that is unsuitable for other use
Applicable on a variety of sites, hugelkultur is particularly well suited for areas that present a challenge to gardeners. Urban lots with compacted soils, areas with poor drainage, limited moisture, etc., can be significantly improved using a hugelkultur technique, as hugelkultur beds are large, layered compost piles covered with a growing medium into which a garden is planted.
Creating a hugelkultur garden bed is a relatively simple process:
1. Select an area with approximately these dimensions: 6 feet by 3 feet
2. Gather materials for the project:
- Fallen logs, branches, twigs, fallen leaves (the “under utilized” biomass from the site). Avoid using cedar, walnut or other tree species deemed allelopathic.
- Nitrogen rich material (manure or kitchen waste work well and will help to maintain a proper carbon to nitrogen ratio in the decomposing mass within the hugelkultur bed).
- Top soil (enough to cover the other layers of the bed with a depth of 1 – 2”) and some mulching material (straw works well).
3. Lay the logs (the largest of the biomass debris) down as the first layer of the hugelkultur bed. Next, add a layer of branches, then a layer of small sticks and twigs. Hugelkultur beds work best when they are roughly 3 feet high (though this method is forgiving, and there is no fixed rule as to the size of the bed. That is where the “art” comes in!)
4. Water these layers well
5. Begin filling in spaces between the logs, twigs and branches with leaf litter and manure of kitchen scraps.
6. Finally, top off the bed with 1 – 2” of top soil and a layer of mulch.
The hugelkulter bed will benefit from “curing” a bit, so it is best to prepare the bed several months prior to planting time (prepare the bed in the fall for a spring planting, for example, in temperate northern climates). However, these beds can also be planted immediately. Plant seeds or transplants into the hugelkultur bed as you would any other garden bed.
Woods containing tannins and….
Pine and fir will have some levels of tannins, but sawdust from these woods are successfully used in composts, typically being allowed to age before mixing with other ingredients.
Wood is high in carbon and will consume nitrogen during composting. This is much less of an issue (if at all) with well rotted wood.
Note: Some woods contain natural toxins and are allelopathic (see http://en.wikipedia.org/wiki/Allelopathy) . These do break down eventually, though it may take years or decades.
Some allelopathic trees: Most or all cedars (Cypress,Redwood, Sequoia), camphor wood, black locust, black cherry, Eucalyptus, tree of heaven (Ailanthus altissima), Black walnut (Juglans nigra), California Pepper Tree (Peruvian and Brasilian), Siberian Elm.
Avoid using living parts of trees or plants that will sprout and colonize your new Hugelkultur bed, such as willows, Acacia or Nutsedge. If you must use them, make sure they are thoroughly dead first.
I have not used “hill culture,” much (yet) but I will in the very near future in my forest garden; I plan on making several areas filled with branch debris and tree chucks that were cut on our property years back. I’m going to fill my holes with fish waste among other things mentioned in this video. Enjoy!
Yours for sustainability,