They say the best things are found in nature and when it comes to forests, our gardens have much to learn. If you think about it, the former have managed just fine without us, while the latter, even with all our watering, fertilizing and manic topdressing, constantly begs for assistance year after year. The irony lies in how nutrients are recycled. Hugelkultur works by mimicking the natural nutrient cycle found in the woodlands, bringing out the bosky best in your garden.
What is Hugelkultur?
Hugelkultur (whoogle-cool-toor), is a German word meaning “hill culture” or “hill cultivation,” and quite plainly, is a raised earthen mound filled with rotting wood. But simplicity aside, it translates into an efficient and ingenious, sustainable gardening practice sure to revitalize your green space.
The benefits of a hugelkultur bed are plentiful and long-term: Rotted wood makes for an excellent soil amendment, packed with all the nutrients and organic matter that your plants need. As it decomposes, wood slowly releases nutrients into the soil, creating rich humus. At the same time, it builds air pockets that promote healthy root development of fruits and vegetables, an often overlooked key to a bountiful harvest. If that wasn’t enough, rotted wood also acts as a sponge, absorbing copious amounts of water, which it then slowly releases, like a timed irrigation system. Depending on the size of the hugelkultur, this can reduce (or even eliminate!) the need for watering and understandably helps the environment too.
Moreover, as wood composts, it warms up the surrounding earth. Together, the increase in soil temperature and locked-in moisture help create a unique microclimate that prolongs the growing season and shelters frost-sensitive plants (think okra, squash and beans). In unison, these factors enhance the overall fertility and vigor of your backyard Eden.
Besides making your carrots sweeter, your tomatoes plumper, and your melons juicier, rotting wood provides the ideal substrate for edible mushrooms. While morsels of wine cap stropharia and crimini get ready for harvest, they secretly turn the wood into mulch that can be used by plants. This activity in turn attracts beneficial bacteria and soil critters such as earthworms and pill bugs. The result: a lush, active, thriving community that inspires the envy of your neighbors. And isn’t that what a garden should truly strive to be?
Addressing the Issue
For the skeptics out there, there can be issues, albeit all avoidable. Decomposing biomass such as wood is known to deplete soil of nitrogen, an element essential for plant growth. However, by adding nitrogen-rich materials such as blood meal or manure, you can offset this effect. Initial decomposition also acidifies soil, but in the long run, actually raises pH slightly. Keep in mind most plants are content in a pH range of 5.5 to 8.0, so this should not be a problem.
Nonetheless, there is one warning — not all tree woods can be used. Some, such as black locust, are resistant to rot while others, such as cedar and walnut, contain chemicals that act as natural pesticides and herbicides. Black cherry should be avoided as well, as it can poison curious pets or livestock.
Construct Your Hugelkultur
Your own hugelkultur can be made in four super easy steps.
1. Gather all the woody waste material you can find. It’s a great way to recycle and reuse dead branches, twigs, logs and even whole felled trees.
2. Assemble the wood pieces into a mound 1 to 2 feet in height or as tall as you please. If you don’t like the idea of a raised bed (please reconsider as it adds visual interest), just dig a trench to accommodate all of the wood, so that it’s even with the ground.
3. Cover the wood with compostable materials, such as dead leaves, sod, grass clippings, used charcoal, coffee grounds, manure and other garden waste.
4. Begin planting! Or if you live in a temperate zone, prepare the mound in fall so that it is ready to go for spring. Once established, your hugelkultur needs little outside intervention for many years!
Ansel Oommen is a freelance writer, calligrapher, and botanical artist residing in New York City. His work has been published in Living Green magazine, Earthly Happenings, and the Long Island Horticultural Society's Newsletter, among others.