Hügelkultur is a centuries-old gardening technique using wood (tree logs) as the base layer in raised beds. The concept has had a resurgence in popularity in recent years, but many gardeners still have questions about how and why to practice hügelkultur. Fortunately, my guest on this week’s podcast, hügelkultur expert Paul Wheaton, is here to share what there is to know about hügelkultur to get off to a great start.
Paul is a permaculture advocate who spreads the word on YouTube and Facebook and in podcasts, presentations, workshops, appearances and writings. He lives in Montana, but his reach is worldwide — his website Permies.com is the largest online permaculture community there is. He’s also penned a book on implementing permaculture in your own garden, “Building a Better World in Your Backyard: Instead of Being Angry at Bad Guys.”
Hügelkultur is pronounced hoo-gul-culture, and according to Paul, it really just means “soil on wood.” That’s not a literal translation of hügelkultur from German, but that’s what Americans have adopted it to mean, he says. A closer translation would be “hill culture.” A hügelkultur garden done right is self-watering, self-fertilizing and space-saving, and never requires tilling.
How Paul Wheaton Became Hügelkultur Obsessed
Paul first tried his hand at gardening in the early 1990s but lost all of his gardens in the first year. He wanted to turn his fortunes around, so in one summer he read 100 gardening books. Gardening became an obsession, and he went on to earn a Master Gardener certification.
He began building raised bed gardens with stone borders but found that the gardens were awfully dependent on him for frequent watering, so he looked for ways that he could water less often.
When he learned about permaculture, that became his new obsession, and he took his first permaculture design course in 2004. That course is where he first heard the word hügelkultur, but when he went on the internet to find out more, there was nothing there. So Paul took it upon himself to put up the first webpage there ever was on hugelkultur. He conducted his own experiments using hugelkultur techniques and shared his results.
In those early days, Paul also discovered an Austrian gardener who put out VHS tapes on permaculture, Sepp Holzer, who was practicing hügelkultur — even though Sepp didn’t call it hügelkultur. They became friends and Sepp shared that he had evolved his techniques quite a bit since those videotapes.
Paul views a lot of blog posts and videos on hügelkultur that make him want to say, “You’re making it super hard on yourself!” His attitude is that hügelkultur should be easy — and free.
Why Hügelkultur Benefits Plants
Paul’s view is that beyond NPK — the macronutrients nitrogen, phosphorus and potassium — the primary nutrient for any plant is the exudates from other plants. Plant exudates are the organic compounds that plants secrete into the soil. Plants use their exudates to influence the bacteria and fungus in the immediate vicinity of their roots, a small area called the rhizosphere. He believes that mycelium networks in the soil are the best way to move nutrients around the soil to the benefit of plants.
Paul emphasizes that hügelkultur is “soil on wood,” and not “dirt on wood.” Sterile dirt won’t do anything with that wood, while living soil will cause the wood to decompose. The microorganisms in soil will create more spaces in the wood to park moisture and nutrients.
The wood in a hügelkultur bed retains moisture, so during dry spells plants have a reservoir to tap into. To achieve this effect, Paul recommends irrigating as you would a normal garden in the first year, irrigating half as much the second year, and no longer irrigating in the third year and beyond. Now, if the bed was built with good soil to begin with, irrigating may not even be necessary in the first year. But if starting with dirt and trying to build healthy soil, don’t skip watering that first year.
The Right Size for a Hügelkultur Bed
A hügelkultur bed doesn’t necessarily need to be large. Creating a 2-foot-tall raised bed with sticks in it is practicing hügelkultur (though more irrigation will be necessary). Paul says those 2 feet of height in a cooler climate are great because they add two weeks on either end of the growing season.
To take hügelkultur to the extreme, a bed can be as tall as 7 feet, and Paul says that can add an additional week or two to the growing season. Another bonus of such a tall bed is that it adds more growing space, because the mound is two sided.
It’s the wood at the base of a hügelkultur bed that maintains the mound’s structural integrity and shape. Even as the wood rots down and the soil settles, the sides of the mound will remain at 45 degrees.
The Right Materials for a Hügelkultur Bed
Paul recommends using large logs when building the base for a hügelkultur bed. The primary reason for going big is to reduce soil-to-wood contact. The problem with too much contact between nitrogen-rich soil and carbon-rich wood is that the nitrogen will get busy breaking down the wood and become unavailable to plants. This is called “nitrogen immobilization.”
If using wood chips or sawdust, there will be much more contact between soil and wood, and much more nitrogen will become bound up.
Paul further recommends introducing diversity to a hügelkultur bed: In one area, use green hay, in another, spread out kitchen scraps, and so on. Even wood chips can be added this way, from various types of wood — though wood chips should be used sparingly for the reasons mentioned above.
The best type of wood for hügelkultur is the wood you already have right where you are, Paul says.
How to Structure a Hügelkultur Bed
To build a 7-foot-tall hügelkultur mound, Paul says to start with a base that’s 7 feet wide. First, lay logs and twigs one layer thick and 4 feet wide right on grade. Next, dig out the soil on either side and plop that soil down on the wood. When you’ve moved enough soil so that you can’t seed wood anymore, add the next layer of wood, and add soil again. Repeat until the mound is 3 or 4 feet taller than grade. Because you’ve also dug 3 feet deep around the mound, the mound’s total height is now 6 or 7 feet tall.
Using several alternating layers of wood and soil will create a mound with better structure integrity, Paul says, and it will also cut down on air pockets. Another of Paul’s tips for better mound integrity is to apply twigs both length-wise and width-wise.
While most illustrations and photos of hügelkultur beds found online show mounds that are built in straight lines, Paul’s method is to create a wavy shape. Straight mounds can catch desiccating and cooling wind in a way that is detrimental to plants, while a wavy mound won’t. Also, wavy mounds will receive different amounts of lights in different areas, creating microenvironments that some plants will take to.
Choosing Crops for a Hügelkultur Bed
A hügelkultur bed will be its driest at the top, so that’s a good place for crops that tolerate dry soil, like sunchokes. At the base, where the mound is its wettest, plant crops that tolerate moist soil, like onions.
Paul recommends a polyculture: Plant many different types of crops and spread them out on the mound, mixing them together. The mound will not only have different moisture levels and sun exposure in different locations, but it will also have varying pH levels. The plants will support each other and the diversity will confuse pests that target certain crops.
How Long Is a Hügelkultur Bed Good For?
In a tropical climate, where the heat encourages microbial activity, a hügelkultur bed may only last for three years, Paul says. But in a cool climate like Montana, where he is, it could last for 30 to 60 years, he says. In a cool climate, the logs inside the mound will decompose at a much, much slower rate, releasing their nutrients to crops over time — which is exactly the goal.
I hope this podcast answered some of your questions about hügelkultur basics. If you haven’t listened yet, you can hear this episode now by scrolling to the top of the page and clicking the Play icon in the green bar under the page title.
What else would you like to learn about hügelkultur basics? Let us know in the comments below.
Links & Resources
Some product links in this guide are affiliate links. See full disclosure below.
joegardener Online Gardening Academy™: Popular courses on gardening fundamentals; managing pests, diseases & weeds; seed starting and more.
joegardener Online Gardening Academy Perfect Soil Recipe Master Class: Learn how to create the perfect soil environment for thriving plants.
joegardener Online Gardening Academy Beginning Gardener Fundamentals: Essential principles to know to create a thriving garden.
joegardener Online Gardening Academy Growing Epic Tomatoes: Tomato expert Craig LeHoullier joins me in leading this course on how to grow healthier, productive tomato plants and how to overcome tomato-growing challenges.
“Building a Better World in Your Backyard: Instead of Being Angry at Bad Guys” by Paul Wheaton and Shawn Klassen-Koop
Disclosure: Some product links in this guide are affiliate links, which means we get a commission if you purchase. However, none of the prices of these resources have been increased to compensate us, and compensation is not an influencing factor on their inclusion here. The selection of all items featured in this post and podcast were based solely on merit and in no way influenced by any affiliate or financial incentive, or contractual relationship. At the time of this writing, Joe Lamp’l has professional relationships with the following companies who may have products included in this post and podcast: Rain Bird, Corona Tools, Milorganite, Soil3, Exmark, Greenhouse Megastore, High Mowing Organic Seeds, Territorial Seed Company, Wild Alaskan Seafood Box and TerraThrive. These companies are either Brand Partners of joegardener.com and/or advertise on our website. However, we receive no additional compensation from the sales or promotion of their product through this guide. The inclusion of any products mentioned within this post is entirely independent and exclusive of any relationship.