Hügelkulturs are raised beds constructed from rotten logs overlaid with organic matter and soil. They aren’t enclosed and therefore slope; henceforth the name: hill/mound (hügel) culture (kultur). Hügelkulturs can significantly reduce water use as the decaying wood acts as a sponge, soaking up rainwater that it slowly releases back into the soil.

The beds are so effective that after the first year, there will be no need to water your crops for many years, provided the bed is of a certain size.

Constructing a hügelkultur is relatively simple, but they have to be of a certain height (between two to six feet). The height is important as it determines how effective it will be at holding water. In general, a six foot bed will require no watering after the first year, while a two foot one will hold moisture for three weeks. Upon construction, a bed will begin shrinking, and a seven foot bed will become six foot, so they should be constructed higher than the desired height. To avoid excessive compaction of the soil, and to maintain good aeration, it is recommended that you build your beds with steep sides, about 45 degrees.

Certain trees are unsuitable as some trees are allelopathic, that is, will harm your crops with allelochemicals that will persist in the soil. Others take too long to rot. Most tree logs should be fine, and there are lists of allelopathic trees and scrubs online, so do some research. Known trees to avoid include cedar, black locust, black cherry and black walnut. Excellent species to use include alders, apple, cottonwood, poplar, willow and birch.

Before building your own bed, it is worthwhile to decide on whether you want to construct it entirely above ground or in a shallow trench about two feet deep. The latter, lower in a ditch, will not impose on the landscape and will be easier to construct - try throwing soil six feet high! It will also save on digging, as you can reuse the materials acquired when digging the trench, and not dig up other sections of the garden. Building above ground is preferable if you already have materials on hand or find digging difficult. Constructing on top of sod has the additional advantage in that once the plant matter breaks down it will produce nitrogen for the soil.

Once you have decided upon the above, simply pile your rotten wood, whether it be logs, sticks, timber or chippings, with the biggest at the bottom. Then give it a good drenching as this will aid decomposition.

Fill in the gaps with kitchen waste, grass, leaves and manure. Adding organic matter is useful as during decomposition wood will both take in, and then release nitrogen, so it is possible that the soil may be nitrogen deficient at points.

Then add a layer of sod upside down. You can acquire turf when building a trench. If you have none, just use soil. Next comes more soil as so the wood is fully covered. The degree the wood is encased is a matter of preference, although anything from a few inches to half a foot works best. Finally, top it off with mulch such as straw that is traditionally used.

Now your hügelkultur bed is complete, it is recommended that you start planting to prevent erosion. Therefore, it is useful to construct in time for the growing season. Over time the wood will decay into rich humus, but at first, the soil will be fairly dense, so certain crops may be unsuitable for planting in its first year. Great crops to plant in this time include members of the cucurbitaceae family such as squash, melons and pumpkins.


With thanks to Jorge from Primrose for this excellent article.