I confess to being a long-term skeptic of the permaculture bed-building technique called hügelkultur, in which waste wood is used as the base layer in compost-filled mounds. Hugelkultur (pronounced HOO-gel-kul-tur) always seemed like a lot of work to me, with extensive digging and piling of soil and dragging about of heavy logs.
But change is good, and due to a convergence of events, I find myself on the verge of hugeling. This past spring after renovating several terraced beds, the poor things looked sadly sunken, and we’d like to avoid the volume issue next year, when we redo two more beds. The beds are being dug out anyway and I have plenty of woody materials on hand, so I plan to gain the 12 inches (30cm) of loft I need at the bottom of the beds using hügelkultur methods.
How Hugelkultur Beds Work
There are endless ways to build beds atop wood waste, which rots slowly and serves as a source of stable organic matter buried deep in the soil profile. Fungi are primary decomposers of wood, so soil near the rotting wood becomes permeated with hair-thin fungal mycelium. Some hugel beds are built atop logs, while others use small brush as woody filler. The best wood is old and ready to rot, for example old logs from an abandoned wood pile, or in my case, a brush pile of weathered fruit tree branches.
In addition to pieces of wood, the most successful hugel beds include layers of organic matter such as rotted hay, grassy sod turned green side down, pulled plants, or food waste. Dryness is a commonly-reported issue with new hugel beds, so it’s also important to sift some soil into the crevices between wood pieces to eliminate dry pockets. To help new hugel beds retain moisture, they can be shaped to have flat or concave tops rather than peaked ones.
Do Hugelkultur Beds Attract Termites?
Well, they can. Termites have no interest in small pieces of wood, like wood chips or buried brush, but they are natural scavengers of buried pieces of wood large enough to support a colony. This is why hugel beds always should be located at least 30 feet (10m) from your house.
Subterranean termites are common in the heavily wooded area where I live, and they are hugely important decomposers of dead wood. I often have seen small colonies in wood used to frame garden beds, and we watch our woodshed for earthen tunnels the termites build to connect themselves to moist ground. But termites much prefer living in standing dead trees, which is a far different ecosystem from buried logs and compost. The small pieces of aged wood I plan to use in my hugel beds are not what termites want.
Are Hugelkultur Beds Worthwhile?
Digging a big hole and hauling heavy wood and dirt is a lot of work, so unless you have access to heavy equipment, think carefully before breaking ground for a hugel bed. Read critical reviews and look at lots of pictures and videos. One of the best reasons to undertake the project is that you have compacted or rocky subsoil. Compared to impenetrable subsoil, a big hugel mound is promising garden space indeed.
Building hugel beds is also quite practical where you want to use broad berms to add structure and dimension to your landscape, or you plan to install berms and swales to channel water. Or, like me, you might simply need to add significant depth to a new or renovated garden bed.
Mimicking Nature’s Plan
I live amidst woods that are rich with fallen trees, some of which have been on the ground for decades. On walks I regularly encounter rotting logs and stumps that have become hills due to accumulated organic matter, examples that prove Nature knows how to put dead wood to good use. We’ve used logs planted on end to frame beds in the past, and they lasted ten years and left the soil better for their presence. As to whether my new hugel beds succeed or fail, I’ll keep you posted. For now, it’s great to look forward to trying something new.