Hügelkultur – an ancient horticultural practice that’s now coming back into fashion

Here at Barnfires we’re going back more than 1 000 years in vegetable-growing traditions by adopting the Hügelkultur or raised-bed gardening system. Used in Germany and Eastern Europe for many hundreds of years, Hügelkultur (literally meaning “mound culture”) is a method of growing food that can be built using locally available materials.

Because this growing technique applies principles that are already present in Nature, we believe that we are getting Nature’s assistance to produce food efficiently without some of the problems associated with conventionally tilled market gardens.

Initially we got excited about Hügelkultur because it seems to be an innovative gardening and farming technique that builds soil fertility, retains soil moisture (making it a good option in the dry Highveld winter months), allows for good soil drainage, reduces the need to weed, and provides a great way to use extra woody materials that are lying around on the property.

Beds under construction

Hügelkultur works by burying woody materials, such as logs, branches and twigs under soil, and then growing plants on top of the buried mound. The wood in Hügelkultur beds soaks up water like a sponge, providing moisture to the plants, and the decomposing wood continually feeds the soil in the bed.

We were fortunate enough to have a kind neighbour deliver several trailer-loads of logs and branches that had already been cut on his farm and they kick-started our Hügelkultur initiative. We combed Barnfires’ 39 hectares for more woody material and so far we’ve have got 22 mounds underway.

After laying down the logs and big branches, we placed smaller woody material on top, including used wood shavings that were gathered up from the barn where the goats and sheep sleep at night. These were rich in soaked urine and droppings. They were followed by a thick layer of veld grass and finished off with a layer of well-rotted horse manure. There are other variations on how to build up your mound, but this was the way we opted for because in the spirit of sustainable horticulture – it was what we had readily available to us.

Hügelkultur mimics the natural conditions found within a forest, where plants grow on top of decaying trees. In a nutshell, Hügelkultur is the composting of organic materials in the same space where you’re growing plants.

If you have the luxury of time, you can allow your prepared Hügelkultur bed to sit for a number of months before planting in it; such as building the bed in autumn for the following spring. This would be a good way of letting organic start breaking down ahead of the growing season. However, seeds and transplanted seedlings can certainly be planted immediately in a newly constructed bed. In our case for instance, an early planting of lettuces is already yielding fantastic results.

In the other prepared beds in the vegetable garden at the back of the guest house (which has been securely fenced to protect it from marauding goats, sheep, horses and cattle) we have planted:

  • Broccoli
  • Purple mustard
  • Strawberries
  • Thyme
  • Spring onions
  • Cabbage
  • Mint

Because Hügelkultur beds continue to enrich the soil as the wood breaks down over many years, they increase their productivity over time with very little work involved. After such a system is established, it will continue to virtually fertilise itself for years without much additional input.

Having a growing system like Hügelkultur that incorporates woody materials encourages the growth of mycorrhizal fungi that are so important in productive natural ecosystems. When present within a garden bed, the mycorrhizal fungi increase the resistance of the soil and your plants to pests and diseases, as well as facilitate nutrient absorption by plant roots.

Hügelkultur is also a great way to store carbon in the soil and to utilise wood as a resource for the garden instead of burning it and releasing its carbon into the atmosphere.

It’s an especially useful growing technique where soil conditions are poor, for example; compacted soils, insufficient drainage, and soil with poor water retention such as those soils that are often present in urban areas.

The Hügelkultur method can be applied in a variety forms as traditional raised bed structures including above the ground in tall mounds, or below the ground in buried ditches. One of the advantages of the above-ground Hügelkultur mounds is that plants can be grown on different aspects of the mound –  such as on the sides, on top and at the ends.

Generally, the bigger and the taller the Hügelkultur  mound, the better, because an increase in mound size encourages more oxygenation taking place inside, and this promotes the best growing conditions – including an optimal internal growth of mycorrhizal fungi.

The beds can be used to grow a seasonal vegetable garden, but they can also be used to grow perennial plants on landscapes including fruit trees, shrubs, and other types of trees.