A new approach – Hugelkultur

John W. Wilkinson and Peter Hill, Amphibian and Reptile Conservation      Reviewed by Steve Head

A form of permaculture, Hugelkultur is a German word meaning “mound culture”. Put simply, it means creating is a large pile of wood buried under layers of soil and humus, and seeks to mimic the decay and nutrient recycling mechanisms of an undisturbed forest floor. The idea of Hugel heaps is rather new to the UK, and offers a number of benefits to growing plants and provides habitat for a host of wildlife.

Hugel mounds can be superficial, with wood and soil on top of damp ground, or more commonly based on wood piled into a trench, which is then covered by smaller pieces of wood, leaves, even old clothes, and topped with soil into which you can plant vegetables or flowers.

For the plants, the buried wood provides a reservoir of moisture and an ongoing supply of slow release nutrients stored in the wood and made available by fungi and other microorganisms during the decomposition process. Hugle heaps also provide:

•  self-tilling soil. As the roots and logs decay they move, aerating the soil
•  a greater growing space for the area used. The piles are best made tall, and the angled sides of the heap increase
    the growing area
•  a south side for light loving plants, with the added benefit of the sun-facing slope increasing warming, and a north
    side for shade loving plants or edible fungi
•  warmer soil, and therefore a longer growing season due to the heat given off during decomposition.


Experimental Hugelkultur bed with wildflower planting at Los Angeles County Arboretum in Arcadia, California.

How long the bed lasts depends on the size of logs you use.  Large hardwood logs and keep going for 20 years, while a filling of straw and twigs can work for 5 or so.
Stacking logs to make a high mound                                 Trench filled with dead wood, ready to be covered in soil

Hugel mounds can be low, concentrating on the moisture and nutrition benefits, but can also be built a metre or more high, increasing the available area for planting.    The open structure of the decaying wood makes a splendid habitat for invertebrates, amphibia and reptiles, especially useful for hibernation. 


Ideally, situate your hugel mounds close to a pond. If both pond and hugel heap are created at the same time, then the top soil from the pond excavation can be utilised on the hugel heap. Light will reflect from the water’s surface onto the hugel heap, combining with the pond side humidity to create a microclimate ideal for growing. Amphibians will breed in the pond and set up home in the hugel heap – ideally placed to feast on slugs and snails!

You will see suggestions of using hugel mounds as embankments to collect liquid water on slopes, either to drain it away, or to encourage it to soak into the soil.  This is inadvisable where slopes are steep and/or rainfall can be heavy, because the light logs can be disrupted and washed away.  See the section on the dangers of hugel swales as earth dams on wikipedia.

If you have tried hugelkultur and recorded how it has helped wildlife, please let us know, and if you can, send some photos.


Links:

Article in Permaculture magazine
Short article by Alys Fowler in The Guardian
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A new approach – Hugelkultur

John W. Wilkinson and Peter Hill, Amphibian and Reptile Conservation      Reviewed by Steve Head

A form of permaculture, Hugelkultur is a German word meaning “mound culture”. Put simply, it means creating is a large pile of wood buried under layers of soil and humus, and seeks to mimic the decay and nutrient recycling mechanisms of an undisturbed forest floor. The idea of Hugel heaps is rather new to the UK, and offers a number of benefits to growing plants and provides habitat for a host of wildlife.

Hugel mounds can be superficial, with wood and soil on top of damp ground, or more commonly based on wood piled into a trench, which is then covered by smaller pieces of wood, leaves, even old clothes, and topped with soil into which you can plant vegetables or flowers.

For the plants, the buried wood provides a reservoir of moisture and an ongoing supply of slow release nutrients stored in the wood and made available by fungi and other microorganisms during the decomposition process. Hugle heaps also provide:

•  self-tilling soil. As the roots and logs decay they move, aerating the soil
•  a greater growing space for the area used. The piles are best made tall, and the
    angled sides of the heap increase the growing area
•  a south side for light loving plants, with the added benefit of the sun-facing
    slope increasing warming, and a north side for shade loving plants or edible fungi
•  warmer soil, and therefore a longer growing season due to the heat given off
    during decomposition.


Stacking logs to make a high mound     Trench filled with dead wood, ready to be
                                                                        covered in soil

Hugel mounds can be low, concentrating on the moisture and nutrition benefits, but can also be built a metre or more high, increasing the available area for planting.    The open structure of the decaying wood makes a splendid habitat for invertebrates, amphibia and reptiles, especially useful for hibernation. 


Ideally, situate your hugel mounds close to a pond. If both pond and hugel heap are created at the same time, then the top soil from the pond excavation can be utilised on the hugel heap. Light will reflect from the water’s surface onto the hugel heap, combining with the pond side humidity to create a microclimate ideal for growing. Amphibians will breed in the pond and set up home in the hugel heap – ideally placed to feast on slugs and snails!l

You will see suggestions of using hugel mounds as embankments to collect liquid water on slopes, either to drain it away, or to encourage it to soak into the soil.  This is inadvisable where slopes are steep and/or rainfall can be heavy, because the light logs can be disrupted and washed away.  See the section on the dangers of hugel swales as earth dams on wikipedia.

If you have tried hugelkultur and recorded how it has helped wildlife, please let us know, and if you can, send some photos.


Links:

Article in Permaculture magazine
Short article by Alys Fowler in The Guardian
Experimental Hugelkultur bed with wildflower planting at Los Angeles County Arboretum in Arcadia, California.

How long the bed lasts depends on the size of logs you use.  Large hardwood logs and keep going for 20 years, while a filling of straw and twigs can work for 5 or so.