Do you enjoy trying out different gardening techniques? Perhaps you’ve developed a recent interest in sustainable permaculture? If so, you’ll definitely be interested in learning about hugelkultur.
It might sound like a strange Northern European holiday tradition involving dirndls and lederhosen, but it’s actually a smart way of creating a long-lasting, nourishing growing environment for your plants.
Let’s take a look at how you can get started with this growing method, and how you can keep it going for years to come.
What is Hugelkultur?
Hugelkultur, pronounced hoo-gul-culture, is a gardening technique that originated in Germany. The word means “hill culture,” and describes this growing method perfectly. The term first appeared in 1962, in a gardening pamphlet created by botanist Herrman Andrä.
In simplest terms, this is a type of gardening where you create raised hill beds made of compostable materials atop large logs. This creates a nutrient-rich mound that you can sow plants into. Since the mounds create nutrients and retain moisture, it’s an efficient, low-labor, and sustainable gardening method.
Are There Different Types of Hugelkultur Beds?
Yes and no. The basic aspect of hugelkultur is that it’s a mound of compostable material that you build on top of logs. Where beds differ is the size and shape.
For example, you can make a massive hugelkultur bed if you use a few big, old oak logs with several feet of compost on top of it. A mound like this could easily be over five feet tall. In contrast, you can do a low bed consisting of just one log and a lot of biomatter like straw and manure on top.
Furthermore, there’s a difference between standard and formal beds. A standard hugelkultur mound looks like an old hill fort. In contrast, some people use hugelkultur methods inside tidy raised beds. As an example, someone could dig a trench, build neat wooden walls around it, and then fill that trench with log bits and organic matter.
Choose the type of bed that will best suit both your land and your needs. A suburban backyard might do better with some neat raised beds, while rural acreage could handle some massive hill forts.
Benefits of Hugelkultur
There are several benefits to using this type of gardening. Let’s take a look at some of them, and how they may benefit you and your land:
1. Eliminates Materials Cluttering Your Property
Since you make hugelkultur mounds out of logs, branches, and leaves, it’s an ideal way to clean up fallen trees from around your property. Provided that they’re of beneficial hugel species, of course.
You’ll also be able to toss lawn clippings and kitchen scraps in there, but more on that later.
2. Hugel Mounds Continually Supply Nutrients to Plants
Since logs take longer to break down, they’ll provide a natural supply of nutrients to your plants over the years.
If you’ve ever heard of a no-dig garden, this is the same principle. The difference is that with a no-dig garden, you still have to supply fresh woodchips each year to encourage continuous composting.
With a hugel garden, the logs keep breaking down year after year, thus releasing more nutrients to the surrounding area. In fact, if you have hardwoods like oaks, maples, or apples around, use those as your hugel base logs. A large one can take up to 20 years to decompose, which means that you won’t have to add any extra fertilizer for a good couple of decades.
3. Extended Growing Season
If you’ve ever created a compost bin, you know that heat rises in there when the composting process begins. That same process occurs inside your hugel garden. Better still, when the mound heats up due to the composting process, it heats the surrounding soil too. An added bonus to this subterranean heating means that your garden’s growing time is extended.
After all, plants only thrive in soil that has been warmed. It’s why we can’t sow many species before the last frost date: the seeds will just die in the cold soil. Since hugel mounds are significantly warmer than the surrounding land, they’re warmer microclimates that sustain life both earlier and later in the season.
This is excellent news for gardeners who have shorter summers because of their planting zone. They can start their gardens earlier and keep them going later thanks to the toasty soil in those mounds. If they add some cloches as well, they might be able to keep growing certain plants well into wintertime.
4. Less Water is Necessary
Many people don’t consider how difficult water can be to come by in some locations. When you live in a place where rainfall is scarce and drought conditions are common, challenging can be incredibly challenging.
Since hugelkultur mounds retain so much water, they don’t need to have much moisture added from an outside source. This is one of the main reasons why they’re so popular in arid locations worldwide (more on that later in this article).
Whether you live in an area where water use is restricted, or you’re trying to live a green, no-waste lifestyle, this style of gardening could be right up your alley: it requires almost no additional water after its first year. During the first year, the logs and organic matter within the mound absorb all the water offered. That moisture is then trapped in the logs’ spongy tissue, as well as the decomposing matter all around it.
After the first year, you shouldn’t have to water your garden more than once a season unless you’re in an extended drought.
5. Raised Gardens are Easier on Joints and Backs
All experienced gardeners know what kind of a toll food gardening can take on various joints. Since we grow food in the ground, there’s a lot of bending and stooping involved to dig, plant, and weed.
Hugelkultur gardens are raised—some quite significantly. In fact, the average hugel mound is at least three feet high. As you can imagine, working with a raised area like this is a lot easier on the gardener’s body, especially if they have joint or back issues.
As an added benefit, this is a great technique to use in gardens or allotments used by disabled gardeners. Just ensure that there’s enough room to maneuver wheelchairs through the hugel mounds and you’re good to go!
6. Adaptable to Any Location
Finally, choosing a hugel garden is a wise idea because it works practically anywhere. For example, if you live in a dry location where you get very little rain, this style of gardening should work for you because of the “sponge” it creates.
If you live in an area with a colder climate, this style of gardening gives you a longer growing season. Youc an adapt these mounds to every locale from Norway to Namibia and everywhere in between.
Which Types of Wood Are Ideal to Use?
You’ve likely noticed by now that there are many different types of trees out there. Furthermore, their wood is suited to a variety of different projects. Just like how some woods are better for firewood than others, some species are better for hugelkultur than others are.
Most hardwood trees are ideal for hugelkultur building. If you have a large forested area near you and several species to choose from, that’s awesome. Aim for logs that are already starting to rot, rather than freshly felled ones. They’ll already be decomposing nicely and the accelerated decomposition rate will jump-start the growing process above.
These are some of your best options for logs and thick branches:
- Black Walnut: Any logs or branches from black walnut trees (Juglans nigra). They’ll exude juglone into the surrounding soil and you won’t be able to grow anything edible on your hugelkultur mound. The one exception to this is pawpaw fruit: it can be companion planted with any walnut species.
- Black Locust (Robinia pseudoacacia)
- Cedar: Have you ever popped cedar blocks into your closet or dresser to ward off moths? Or perhaps used cedar chips as a weed-suppressing groundcover? These trees (Cedrus spp.) are allelopathic, meaning that they’re packed with natural herbicides and pesticides, as well as antifungal and antimicrobial agents. As you can imagine, this means that they’re likely to kill off young seedlings nearby as well as beneficial microbes and insects.
- Camphor: For the same reasons as cedar, camphor trees (Cinnamomum camphora) should be avoided.
- Pepper Trees: For the same reason as above, don’t use pepper trees (Schinus spp.).
- Black Cherry: Black cherries (Prunus serotina) are allelopathic
- Coast Redwood: Unless it has fallen naturally, don’t use coast redwoods (Sequoia sempervirens) because they’re endangered.
- Pine: Pine trees (Pinus spp.) are allelopathic.
- Yew: Yew trees (Taxus baccata) are poisonous.
- Tree of Heaven: These beautiful trees (Ailanthus altissima) exude potent herbicides. This means the wood will prevent seeds from germinating and flourishing nearby. By all means, bury some of this stuff in areas where you’d like to kill off nearby plant growth. Just don’t use it anywhere near locations where you actually want to grow food or medicine.
Other Notes on Wood
In addition, it may seem like common sense that doesn’t need to be pointed out, but don’t toss any diseased plants into the mound you’re building. Yes, you need to fill it with organic matter so it’ll decompose and nourish the plants above. That said, if you toss in plants infected with soil-borne pathogens like downy mildew, powdery mildew, or mosaic viruses, guess what’ll infect anything you plant there?
The same goes for using hay (which has seeds in it) and live, green wood. We’ve touched upon why using wood that’s already decomposing is best for hugelkultur piles, but there’s a secondary benefit. If you plant live wood, there’s a chance it’ll root and sprout. Basically, you could be planting young trees beneath the soil, which will sprout northwards and destroy the mound you’ve just labored to build.
How to Build a Hugelkultur Garden
When planning your hugel mounds, the first thing to do is scout out a location. It should be a flat-ish area that receives a lot of sun and won’t be shaded out by large trees. Since you only need to dig down into the soil a bit, it’s absolutely okay to build hugel piles on top of flat rock, depleted soil, etc.
Don’t ever build a hugelkultur mound on top of your septic field. The weight it creates will be too much for the system below and that’ll be a horror show that nobody wants to deal with. Additionally, don’t dig or build anywhere near submerged power or gas lines.
Now that you know the don’ts, let’s get going:
1. Remove the Sod and Gather Materials
When you begin to construct your hugel garden, you’ll need to remove the grass-covered sod from the area. You’ll use a spade to cut around the perimeter, and then cut sections of the sod to move away. If the soil beneath is quite dry, you should be able to just roll the sod off to the side.
Just don’t discard the soil or the sod from this location because you’re going to use it inside the hugel mound. Simply move it away from the area until you need it.
Then, collect enough large logs and branches to create the kind of mound you’re aiming for. If you’d like a fairly tall mound, then make sure to collect quite a bit of material.
2. Dig a Trench
When the area is clear of sod, dig a trench that’s at least one foot deep. This is where you’re going to place your logs.
Make sure the trench is deep enough and wide enough to fit the number of logs you’ve prepared for this gardening project. You can do this by measuring out the longest of your logs, and then digging a trench that’ll accommodate it.
Aim to dig a trench that’s a little bit larger than you think you’ll need it. It’s better to have a bit more room to move things around in, and you can always add more “stuff” into the pile.
3. Add the Logs and Water Them Well
Next, you’re going to fill up the trench with those decomposing logs. Most people place their logs in the trench horizontally and then stack them on top of each other. Alternatively, if you’ve bucked the logs into several pieces, you can place those smaller pieces vertically.
If the wood is already quite rotten and falling apart, just toss whatever you have in however you can. Choose whatever option allows maximum log placement. Remember that the more materials you add into this garden, the longer the nutrients will last and the better absorption you’ll have.
Make sure to water the logs well before you add anything else. Seriously, water the heck out of them at this point. It’s absolutely okay if the moisture creates little mud puddles around the logs: it’s better to ensure that they’re absolutely sodden than to risk them drying out.
4. Start to Build Your Mound
Once the logs are in place and soaked to saturation, it’s time to pile the rest of your composting materials on top of them.
Keep in mind that logs are incredibly high in carbon. Just like in compost heaps, hugelkultur mounds need to have a good mix of carbon and nitrogen to create a good nutrient balance. If there’s insufficient nitrogen in the mound, those carbon-heavy trees will burn it off as they decompose.
As a result, you need to make sure that you pack a lot of nitrogen-rich materials into the hill you’re building. This means that you should lay off using raked dead leaves, and use green lawn clippings, freshly cut green leaves, and plant-based kitchen scraps instead.
You should comprise the layers of the following:
- Base: Logs and branches, wood chips, sawdust
- First layer: Sod, placed grassy side down
- Second layer: Green leaves, grass clippings, straw
- Third layer: Manure, moderately aged compost, dry leaves
- Fourth layer: Topsoil, very aged compost
Don’t Be Shy About Building High
If you’re worried that your hugelkultur pile is getting quite tall, that’s okay. This makes it a lot easier to plant in and work with—much like a raised bed. You’ll have plenty of room to grow all kinds of plants on both sides as well as the top.
Furthermore, that mound is going to hold plenty of moisture so you don’t have to water it as often as the rest of your garden.
Now it’s Time to Plant!
This is the moment you’ve been looking forward to! It’s time to plant seeds or seedlings into that glorious hill you’ve built.
Before you get started, spend a sunny day taking note of sunfall on the mound that you’ve built. Take photos every hour to determine which spots get the most sun, and which are shaded out most over the course of a day. Try to do this once the trees around you are in full leaf, rather than in wintertime: areas that get full sun in January may end up fully shaded in June.
Once you have this sorted out, you can plant accordingly. Note that some plants grow better on hugelkultur mounds than others do.
Plants to Avoid
Avoid planting most root vegetables, especially those that root deeply like potatoes. If you really love roots, plant small varieties like hailstone radishes or small Nantes carrots.
Plants that Grow Well in Hugelkultur Beds
Nightshade such as tomatoes, peppers, eggplants, as well as brassicas, leafy greens, alliums, various culinary and medicinal herbs, and small berry bushes.
Where to Plant What
The top of your hugelkultur mound is known as the “plateau.” This is going to be the deepest spot, but also the driest. It’s where you’ll want to plant those root vegetables (if you want to plant any), as well as woody Mediterranean herbs that need good drainage. Thyme, oregano, summer savory, etc. will all thrive here.
You should place sun-loving plants that take longer to mature in spots that get the most sun. This is where you’ll grow tomatoes, peppers, brassicas, cucurbits like zucchini and cucumber, and alliums like onions and chives. Remember to do your research regarding companion planting so you don’t plant incompatible species adjacent to one another.
Place tall plants like hot peppers, artichokes, and Brussels sprouts close to the bottom of the mound. It’ll provide them with stronger stability for their roots, and they’ll be able to retain more water closer to the hill’s base.
On the shady side is where you’ll plant low-growing, low-light plants like leafy greens and tender herbs. This is where you’ll grow your kale, lettuce, spinach, basil, coriander, parsley, and dill.
In the intermediate zones between the sunny and shady sides, plant species that thrive in partial sun, but need more moisture. I like to plant nitrogen fixers like bush beans or field peas in these areas.
Fill the Mound
Make sure to plant every inch of your hugel mound with something. Even if it’s some herb seeds. Every inch that you leave bare will be an opportunity for nature to step in with some crabgrass, wood sorrel, or other local weed.
When in doubt, plant some native pollinator seeds. All plants benefit from indigenous local flowers that’ll entice bees and butterflies over for a snack.
Potential Hugelkultur Issues
Every garden has its issues, and hugel mounds are no exception.
For example, the top (plateau!) can dry out quickly and doesn’t have the benefit of the moisture being collected below. You can combat this problem by working vermiculite, peat moss, and coconut coir into the soil to help retain moisture.
Additionally, there will inevitably be some shrinkage and/or erosion from the top of the mound. Always add more on top than you think you’ll need. Then add some more.
Avoid putting any rotting logs or plant matter on top of the mound. This will just lead to contaminated vegetables and herbs, rather than adding any nutritional value. If you’d like to add extra nutrients, add some aged compost on top instead.
Watch for Nitrogen Deficiency and Disease
If you find that some of your plants are showing signs of nitrogen deficiency, you may not have added enough green, nitrogen-rich matter into the mound when you were building it. You can counteract this problem by offering the entire mound a nice compost tea drink weekly until the issue improves.
Should you experience a situation where all the plants are suffering from a damping-off or are afflicted with powdery mildew or similar, there may be a pathogenic infection inside the mound itself. If this happens, pull all the plants out and burn them. Then tear the mound open and treat the contents with a strong organic fungicide. At this point, you can close it back up and cover it with a weighted black tarp. The internal heat plus fungicide should kill the pathogens.
After that, let the mound go fallow for at least three years before trying to plant it again.
Are Hugekultur Gardens Proven to Be Effective?
That depends on whom you ask, and in which context. Some proponents claim that hugelkultur mounds are incredibly effective at providing long-term nourishment to plants. This seems to work especially well in areas that have experienced significant nutrient depletion and soil loss.
For example, a study in 2016 showed hugelkultur to be remarkably effective in preventing desertification. These mounds held significantly more water than the surrounding areas and were thus able to replenish the area with vital micronutrients. As a result, since water and organic matter are held in place by the structure, the hugelkultur mounds helped to prevent desert spread.
Hugelultur Throughout History
People used this technique to good effect in other arid climates. For example, the people of northern Cameroon appear to have been using their version of hugelkultur for thousands of years. A 2017 paper published in Germany refers to notes taken by explorers in Cameroon between 1903 and 1918. They noted the agricultural practices done by the local Duala people:
“Die Landwirtschaft war ausschließlich die Sache der Frauen, während der freie Duala Mann sich dem Nichtstun im günstigeren Falle dem Handel oder Fischfang widmete. Das Fällen und Brennen des Urwaldes wird von Sklaven besorgt. Die Frauen trieben die Hugelkultur während bestimmter Jahrzeiten.”
If your German is a bit rusty, this basically says that agriculture was done exclusively by the women of the tribe, while the men hunted, fished, and enjoyed idle pastimes. Tree felling was done by their slaves, and the women used these fallen trees to create hugelkultur mounds for food gardening at certain times of the year.
There haven’t been any recent peer-reviewed studies that prove hugelkultur’s effectiveness, but nor have there been any studies proving that it causes any harm. Since this technique has been used worldwide for millennia, there’s likely something to the practice.
Ultimately, it’s up to you to decide whether you’d like to try it or not. If you have a bunch of rotting wood lying around, try building a mound as an experimental project. Plant some of your favorite vegetables and whatnots on top, and track their health and productivity over the next few seasons. Then you can determine for yourself whether hugelkultur is worth the work or not.
- Laffoon, M (August 2016). “A Quantitative Analysis Of Hugelkultur And Its Potential Application On Karst Rocky Desertified Areas In China“
2. Die Besteuerung unter deutscher Kolonialherrschaft in Kamerun im Bezirksamt Duala (1903-1913) Wissenschaftlicher Aufsatz, 2017