Hugelkultur Beds: How to Build Now for Spring Planting

As our summer crops wind down, the season’s transition marks an ideal time to put our bare beds to bed, whether with a cover crop or another regenerative method to improve soils. During the quiet season, nature does the work for us with bed prep in fall and winter. 

Hugelkultur is a technique that builds soil over time, mirroring natural forest systems. It incorporates layers of decaying logs, sticks, and organic material to fill the base of a bed, whether raised or in the ground. As the organic components break down over time, they add nutrients and new soil to the mix.

If you build hugelkultur beds in the fall, you give them time to settle and cure before spring planting. They’ll be ready for vegetables and other favorite crops as temperatures warm. Like raised beds, they even warm earlier than traditional ground-level beds.

Enjoy the fun of experimenting with a permaculture method that brings lasting results. Follow this guide to find out how to build hugelkultur beds.

About Hugelkultur

You can build hugelkultur beds in new or existing planting areas. German for “mound culture” or “hill culture” and used for millennia, the gardening method dates to the Middle Ages. It creates a sloped or raised bed filled with topsoil, wood, and other organic materials.

It relies on layers of nitrogen and carbon-rich materials. Done correctly, the self-sustaining setup retains moisture and needs little supplemental irrigation and fertilization. The mounding forms can also slow stormwater and serve as windbreaks.

The permaculture method carries long-term benefits with the right plan. Advantages include:

• Resource conservation and soil improvement: As the organics decompose to create compost, the composition retains moisture, shows good drainage and aeration, and is nutrient-rich.
• Adaptable: Works well in varying sites, from short raised beds to larger landforms.
• Low maintenance and economical: It takes advantage of local site materials and biomass and needs little tending other than regular weeding and garden tasks for plantings. Because we’re using filler material for bulk, we need less soil (and less investment) for filling beds.
• Long-lasting: Extends the growing season with earlier warming.

Hugelkultur in the Ground

Hugelkultur is useful for building beds at various sites. It can be a linear bed, curved, or a series of mounds in a circle or rowed configuration.

Three feet wide by six feet long by three feet high is average for home gardens, though they can get much larger if the landscape warrants it. A typical setup contains larger logs at its core, smaller branches, twigs, and leaves, and “green” nitrogen-rich material like grass clippings, straw, or manure.

The mound can be any height and slope you desire based on the size and amount of fill material. Big logs mean a wider and taller pile, while smaller branches create less height. Because of the mounding structure, hugelkultur expands the growing surface. Keep in mind the slope for planting (too steep may make for seeds that wash).

The base of the mound can be flush with the ground for building up. The method often involves digging a trench to fill and building beds from there. A two to three-foot deep trench allows for increased water capture and runoff control, a reservoir for increased nutritive material, and less height for building up. It also means more labor in the digging and more fill material to create a mounded system.

Consider whether you’ll add a border to base (like logs or pavers) to contain the sides, or create a natural flush with the soil surface. The height reduces over time as the core breaks down.

To build hugelkultur beds, choose a site with good sun exposure to grow the greatest variety of crops. Situate it at a lower point or perpendicular to water runoff to capture the flow of stormwater. Rainwater runoff speeds up decomposition.

To Fill Raised Beds

Hugelkultur is an efficient way to fill raised beds while improving the soil base over time. It brings the benefit of needing less soil and compost to fill the whole of the bed, which can be costly. Raised beds offer an advantage to the method as the sides create a border to contain the entire material.

For raised beds, use smaller woody material (rather than large logs) to form the bulk of the wood layer. Smaller branches and twigs will come in handy for the smaller scale of raised beds. If you don’t have access to branches and sticks, corded firewood is a viable base option.

Select and Place the Wood

Hugelkultur to build beds takes advantage of site materials and debris, keeping woody material out of the burn or dump pile. Nearly any type will work, especially hardwood species like aspen, oak, and poplar. A few exceptions to avoid include:

Larger material takes longer to break down, even years. For raised beds and smaller setups, incorporate smaller woody debris for faster decomposition.

Layer the Materials

Plan to water in each layer and tamp it down to reduce air pockets when you build hugelkultur beds. Watering and tamping help to secure the structure and create a solid foundation for root development and decomposition.

Start at the bottom of the in-ground or raised bed to create a foundation for the materials. Logs, branches, and leaves provide carbon layers, while grass clippings, kitchen waste, and manure supply nitrogen. The nitrogen offsets the carbon and nitrogen loss that occurs as logs break down. The “greens” provide a buffer to the “browns” as the composting process happens.

Begin with a base and central core of larger logs or branches to fit the scale of the bed. Surround the core with several inches of green material. Then, build up smaller sticks and stems. Surround these with another layer of the nitrogen-rich material.

Add Soil Media

The final toppings to build the hugelkultur beds are topsoil (or raised bed potting media) and compost. A few inches at the top of the mound round out the composition and make for easy planting.

Add a compost layer each season to compensate for the materials that break down internally (reducing bed size). The compost continues the cycle of building nutritious soil.

Plant and Mulch

If we build hugelkultur beds in the fall, a legume cover crop is helpful for fixing nitrogen in the upper level of soil. If there’s time before your first frost date, give cover cropping a try. It’s also fine to leave the beds bare as they begin to cure over the fall and winter.