By Laura McKissack
Photography of hügelkultur beds at in.gredients by Whitney Arostegui
Back when I began teaching and was freshly moved into a new place, I didn’t have the money to purchase new soil for a garden. Instead, I piled sticks and leaves onto a raised bed and covered it with some soil and compost I’d transported in coolers from my old garden. I had a great garden that year!
I didn’t know it then, but people have been making garden beds like mine for years, and the method even has a name: hügelkultur. A typical hügelkultur garden bed consists of logs and sticks, loose sod (green-side down, over the logs) and soil. As the wood rots, it becomes spongelike—retaining moisture and nutrients and releasing heat, thereby extending the growing season and eventually reducing or eliminating the need to feed or water.
Beds are, ideally, three or more feet tall, and can be fully above ground or partially buried. They can be built up six feet or more, adding to the ease of harvest time. The height additionally allows for a larger growing space in a smaller area.
It takes about two years for a hügelkultur bed to become fully established and begin to produce its own nitrogen, but planting can be done right away. Pockets of air allow wiggle room for roots and moisture retention, and as the soil settles into the pockets, it tills itself—keeping it fluffy. Hügelkultur is great in swampy areas of the yard as it will absorb the moisture and hold it, making it available to plant roots but not sitting on the surface.
The type of wood used in the bed will affect how long it takes to break down. Some acceptable woods to choose are those from oak, ash, elm, pecan and dogwood. Fresh wood is fine but will take longer to rot, and some varieties of trees decompose slower than others—black locust can take 70 years to rot, for example. Since allelopathic trees like cedar and pine produce certain biochemicals that can harm other organisms, they’re also a poor choice, though some gardeners have used them successfully. It may help to leave these types of wood exposed for a year or more before burying them. Other types of wood, such as black walnut and chinaberry, are toxic and will prevent germination of many plants; they should not be used for a food garden. No matter what type of wood is used, nitrogen-producing grass clippings, kitchen scraps and compost must be added periodically until the bed is established—this is the reason for placing the sod, if using it, facedown over the wood.
In the first year, large-leaf vine fruits and vegetables like melons, potatoes, squash and cucumbers work well in the garden; they’ll hold the soil together as it settles, and the plants will benefit from the space. Eventually, the bed will flatten out, and can be kept that way or built back up again with more wood.
I spoke with Lauren Welker, store manager at in.gredients, about their Hügelkultur beds. Since the soil in East Austin is high-quality and easy to work, they dug a trench about a foot and a half deep for the wood to rest in, then built it up about another foot and a half above ground. Welker notes that since April of 2012, the bed had already settled significantly, but the harvests have continued to be plentiful. “Throughout July and August, I was watering about once a week, and the garden thrived,” says Welker. But she cut down to watering twice a month in the winter. “One of the best things we did was to plant melons,” she adds. “They had tons of room to grow and the leaves kept the soil cool and moist. [Hügelkultur has] worked really, really well. It’s perfect for Central Texas.”
Many local organizations offer classes on water conserving garden techniques like hügelkultur. Austin EcoNetwork’s EcoCalendar and the Austin Permaculture Guild’s Yahoo Group are excellent resources for finding all manner of organic gardening and permaculture classes. Hügelkultur is one of many great ways to get more out of the world around you while preserving space and resources at the same time.