Although the term “hugelkultur” was coined by German horticulturalists Hans Beba and Herman Andra in the late 1970s, the actual technique has probably been used for thousands of years. Roughly translated into “hill culture”, this method consists of creating raised garden beds by covering rotting wood with compost and soil, and then planting into them. If you think about it, it’s really just re-creating the effects of forest floor decomposition—but in one’s own garden space. Learn how to make your own after the jump!
Illustration by Paul Wheaton
The way that hugelkultur works is best described in the book Gaia’s Garden, by Toby Hemenway:
The decomposing organic matter in hugelkultur beds raises the temperature just enough to boost plant growth. Another advantage: As the woody brush rots, it releases nutrients slowly, and also holds quite a bit of water.
That sounds rather efficient, doesn’t it? You’ve likely come across natural instances of hugelkultur before and never even noticed what was going on, as all the magic was happening beneath the soil. If you’ve ever taken a walk through the forest (which I really hope everyone has), you’ve probably noticed how lush all the greenery is in there. In the woods, nothing ever goes to waste: When a tree branch falls onto the forest floor, it will sink a bit into the earth and humus there, and slowly accumulate compost and soil over it as leaves fall. Seeds from trees, fungi, flowers, and lichen will find their way over to the gloriously decomposing pile of nutrients that the log will become, and before you know it, that area will be covered with new life. Eventually, as the log disintegrates, the area around it will sink down to the new “ground level”, and all the goodness released from the broken-down roots, mulched fallen leaves and such will nurture both the existing soil, and future generations of new growth.
Image © Plant Chicago
Creating the Beds
To create a similar effect in one’s own garden, we aim to re-create the layers that would accumulate atop the fallen wood, so the layers end up being in order like this:
- Bottom layer: logs and thick twigs
- Next layer: a thick pile of dead leaves. You can also use dry straw
- Middle layer: lawn clippings, green leaves
- Penultimate layer: mature compost
- Top layer: topsoil
When making your own, you can create them as low or high as you’d like. Some people like to dig trenches and place logs into it so that the compost and soil spread overtop will create a nearly flat surface, while others may pile logs and twigs a couple of feet high to create tall ridges. The former technique works well to create the illusion of a standard garden, while the latter has benefits such as giving you more surface space to plant on, and the ability to harvest food without having to bend and stoop too much. Hugelkultur can also be used inside raised garden beds, and even in large planter pots.
Since the woody core of each mound releases these nutrients, and the wood fibres suck up and retail water, hugelkultur beds don’t need to be fertilized or irrigated very often. They will, however, suck up nitrogen for the first year or two, so try to avoid planting annual vegetables in these beds until the third or fourth year. Aim for potatoes, tomatoes, lettuces and other edible greens, beans, perennial vegetables, and even berry bushes. Skip plants like squash or broccoli until the mounds are well established. Over time, the breakdown of the wood within will cause the mounds to collapse a little bit, so you’ll need to add compost layers in order to maintain them, and to add more nutrients to the soil.
Image © Plant Chicago
There are many benefits of hugelkultur, and one of which is that the decomposition going on in the heart of the mound will raise the soil’s temperature, thus giving you a longer growing season! This means that not only can you start seeds earlier, but you’ll likely be able to keep harvesting food for a good few weeks later than the average gardener. Should you decide to plant early/harvest late, be sure to give your plants a bit of additional help by covering seedlings with burlap to protect them from late frosts, or by using cloches and such to fend off early ones in the autumn.
Although the ideal place for a bed like this is a sunny spot on your land, these can also thrive in partially shaded areas as well. If you plan to place your bed in a little-used spot that doesn’t get a lot of sunlight, be sure to fill it with plants that do well in dappled or partial shade, such as bok choi, arugula, spinach, lettuce, and scallions. Also, keep in mind that the “elbow” area where the hill meets flat land will be extremely nutrient rich thanks to runoff from above, so it’s a good idea to plant heavy feeders such as squash, pumpkins, zucchini, melons, eggplant, and cucumbers there.
If you decide that you’d like to make the borders around your hugelkultur bed a bit “prettier”, you can edge them in a number of different ways. Some edge theirs with holed bricks or cement blocks that can have herbs or decorative flowers grown within them, while others might use natural stone. Intricate branches or driftwood can make interesting borders, or you can just leave them natural and let them merge into their surroundings. However you decide to build and decorate yours, it will undoubtedly be a small masterpiece of permaculture, and you’ll be able to reap the benefits of your hard work for years to come.