A raised garden bed is a fantastic way to add value to your greenery. One of the perks of a raised garden bed is the liberty to control what goes into your soil. However, before using a raised garden bed, you must first fill it.
You can fill a raised garden bed with logs. It is a cost-effective method of raising the bed’s height. The logs will eventually decompose and release essential nutrients into the soil.
In the rest of this article, I will throw more light on what this gardening method entails, how to fill your garden bed with logs, and the benefits you stand to gain. I will also list some of the best wood you can use for your garden.
One thing to note. We often think of raised garden beds as framed structures but the term is also used interchangeably in some areas with mound beds. Ultimately, the end goal of thriving plant growth is the same.
Origin and Practice of Filling Raised Garden Beds With Logs
The method of building a raised garden bed with logs is an ancient European practice of growing plants in a mound of rotten wood and plant remains. This method is often referred to as Hugelkultur. Hugelkultur is a German word translated into English as “mound culture.”
Mound culture involves layering logs, plant debris, compost, and topsoil in a pyramid design. Raised garden beds can have surface areas as large as 20 feet (6.1 m) and may be as high as 6 feet (1.83 m).
However, the height of the mound will eventually reduce as the logs decompose.
There are several claims that the practice of filling raised beds with logs began centuries ago in Germany and some other parts of Eastern Europe.
However, the first mention of this practice in any publication wasn’t until the 1960s, when German gardener, Herman Andra, explained this gardening method and provided details of his experience using it in his gardening booklet.
Herman Andra’s advocacy for hugelkultur was influenced by his observation of how plants grew in wooden remains on his grandmother’s farm. This observation made him a strong proponent of the “hill culture” at a time when the “flat culture” was very prevalent.
Years later, other advocates like the Austrian permaculture advocate Sepp Holzer and Paul Wheaton became interested in the Hugelkultur trend and promoted it even further (source).
Here’s an excellent video demonstrating what happens when you bury logs in a raised garden bed:
How To Fill a Raised Garden Bed With Logs
The trick to getting the most out of a raised garden bed that is filled with logs is knowing how to fill the bed correctly.
Here are a few steps on how to fill your raised garden bed with logs:
- Find a good spot. Place your garden bed in a location where it can get ample sunlight. You also want to ensure that the garden bed is parallel to the slope of the land so that every part of the bed gets equal amounts of water.
- Create a barrier. Add layers of cardboard to the bottom of your bed to act as a barrier. Cardboard will inhibit the growth of weeds and will eventually decompose so that your plants can access the soil under the bed.
- Arrange the logs on the barrier. Now you can start filling your garden bed with logs up to half the height of your bed. Start with large logs and place the smaller ones last. For a 4-foot (1.22 m) bed, you can fill the logs up to 2 feet (0.61 m). Using old and rotten logs is perfectly fine.
- Fill spaces with small branches and sticks. Once you fill the bed with logs and tree branches, you will notice a few spaces here and there. You can fill those spaces with smaller branches or sticks. Whatever you do, ensure that the combination of all the logs, sticks, and large logs stays within the maximum of half the height of the bed.
- Add plant remains. Next, add some plant waste to the mound. Suitable plant matter to consider are grass clippings, straw, kitchen waste, and cut leaves. One or a combination of these will be helpful to your bed. Make sure that you keep all plant waste within 20% of your bed’s height.
- Add compost. You can use finished compost if you want from your own compost pile or commercially purchased. You may also opt for worm castings or composted leave molds.
- Fill with topsoil. Finally, add a layer of topsoil to the hill. Ensure that you use a rich soil mixture, or all your hard work may go down the drain (source).
What Is the Best Wood for Hugelkultur (PAA)?
The type of wood or logs you use to fill your raised garden bed can significantly affect the results you see, and not all woods are suitable for filling your garden bed.
The best wood types to use for hugelkultur are old logs that have started to rot. You can use hard or softwood. However, hardwood will decompose slower than softwood and will last longer. You can use logs from a tree stump or from an old house.
Examples of woods that work best for filling raised garden beds include:
- Rotten willow
- Well-aged camphorwood
Avoid filling your garden bed with black locust or redwood as these wood types are highly resistant to decomposition and can inhibit seed germination. You should also avoid using black walnut because it contains toxins that can hinder plant growth.
Benefits of Filling a Raised Garden Bed With Logs
Filling raised garden beds with logs has proven to offer many benefits (source).
Here are a few benefits to using logs in your raised garden bed:
- Provide a constant supply of nutrients to plants over a long period.
- Logs hold water during rainfall or watering periods and release the water during drier seasons.
- Improve soil aeration.
- Reduce soil erosion.
- Help gardeners control what goes into the soil.
- Serve as a legal and eco-friendly way to get rid of waste wood.
Filling a raised garden bed with logs provides a constant supply of nutrients to the soil, which are essential for healthy plant growth.
You can also fill your raised garden bed with soil if you use suitable wood and follow the proper steps. Follow the tips and processes I have shared in this article to enjoy the benefits of this gardening method but be sure to avoid the wrong wood types.
Choose well-aged wood over fresh wood for your raised garden bed. In addition, consider using hardwood instead of softwood, especially if you are keen on longevity.