Is a raised bed for you? If done right, it should absolutely be. Using this method of filling your raised beds can be a huge benefit, especially if you want to focus your finances on the highest quality growing medium to top it off.
But what exactly is hill culture and why are raised beds beneficial? Is this technique more valuable in its original mound shape, or does it work better when enclosed in an elevated garden? And does it actually steal nitrogen from your soil and cause plant problems?
Let's examine the sphere culture in much more detail. We're going to talk about what materials should fit in your ball culture bed, what absolutely shouldn't be included, and why these things are important. We cover the mix you should be covering your bed with too. And by the time we're done, you'll have everything you need to be successful in the raised bed!
What is hill culture?
A traditional hill culture hill. Source: eggrole
This strange-sounding word (pronounced Hoo-Gell-Kultur or Hoo-Gull-Kultur, depending on who you ask) is actually German for "hilltop". In its original form, a shallow pit was dug and filled with rotting wood, gradually creating a long and narrow mound. Dirt would be piled on the logs, creating a long, tall structure that offers much more planting space than a flat garden bed.
To begin with, the logs add more volume to the bed. As they gradually decompose, the mound gradually subsides and the rotting trunks inside hold additional moisture. As long as it remains fully planted, the soil layer is hardly eroded and it becomes a small ecosystem of its own.
In raised beds, this isn't the most common process used. Sure, you could create a long, narrow bed and fill the center with logs and then pile dirt over it for a more traditional mound structure. But for most people who grow in raised beds, they just want enough potting soil to make nice, level beds.
Hill culture raised beds offer the best of both worlds. If you're building a ball culture bed, use wood to make a little less than half the material for filling your raised beds. Other materials such as grass waste, leftover food, coffee grounds and the like can be used to fill the wood and speed up the decomposition process. In addition, add your preferred growth mix.
With this method, you can use permaculture techniques to reduce the amount of materials needed to fill your hill beds. At the same time, you can reduce the number of branches, logs, and other wooden materials that may be lying around. If you get it right, the hill culture part of your bed should be free and save you some money.
Advantages and disadvantages of Hugelkultur beds
Many different benefits have been attributed to hill culture beds on the internet. Let's list just a few of the most common:
- reduces the frequency of watering
- can consume old wood or prevent it from being burned in a pile
- increases the surface area of your garden beds
- can generate heat when the wood decomposes
- is an inexpensive way to create a high garden bed
All of these things sound amazing, don't they? But, like most things you can find online, there are both good and bad in all of these things.
Sure, a hilly bed can reduce watering somewhat. However, most of the benefits of water retention are useless until the wood actually begins to rot to the point where it is spongy and can share that water with the surrounding growth media. This can take years if you start with huge logs.
Unless you grow a lot of trees, live in a forest, or live near orchards, you probably don't have access to a lot of reclaimed wood. That means you will likely have to find sources of wood yourself. While there are options for finding large logs, they may be larger than you want and you will need a log splitter to shrink them to the size you want. Many people choose to buy a cord of firewood and use that to build their beds. However, if you're trying to build cheaply, it might not be ideal.
The mounds, built using traditional hill culture methods, add to the surface area of your beds. But what if you don't want to build mounds that rise above your raised bed walls? They don't have the same enlarged area and may not have any larger area at all.
Most raised beds will warm up earlier than a soil bed in the spring, so the warming aspects are not necessarily needed. However, wood is also carbon-tight and does not normally give off much heat when it is broken down. They are nitrogen-tight materials that give off heat when they decompose.
Find wood that is less than half the height of your bed.
What are the advantages of building a hill culture garden bed?
In my experience, the real benefits of a Hugelkultur raised bed are as follows:
- Great way to use up branches, small logs, wood shavings, wood waste, and virtually any other wood material
- Will act as a reservoir of water at the bottom of the bed over time
- Can be extremely inexpensive to build
- Adds an abundance of organics to your soil
- Definitely reduces the amount of soil you need to start your beds
- Reduces the compaction and shrinkage of your raised beds
This is a much more realistic representation of hill culture in raised beds. It won't work miracles, especially if it's brand new … but over time, the benefits far outweigh the negatives.
Does rotting wood steal nitrogen?
Mix up a good mix of rich soil for your bed.
One of the most common problems alleged by those who have experimented with hill culture is that the decomposing wood is drawing nitrogen from the surrounding soil. Claims of failed plantings are common,
In these cases, I just have to ask how little soil they put on their mounds.
You need to have more than half the material in your raised beds as the soil you will garden in. Only the soil that is directly against the wood has nitrogen loss and your goal is to limit the amount of soil pressed directly against the wood.
The best way to do this is to wrap the wood in nitrogen-tight materials. Whether you are using thin sticks or thick logs, you need to provide a few inches of nitrogen-proof material on all sides for the best effect and evenly break your bed apart. This nitrogen-tight material will also fill in existing gaps and keep the soil where you want it to be.
By incorporating this nitrogen-rich green waste into your wood, you shouldn't experience nitrogen theft by the wood as it decomposes. Assuming you water as usual, over time some nitrogen will wash through your soil anyway and replenish the nitrogen supply of the wood as it decomposes. Fertilize as usual and you will have no problem at all.
How to layer raised beds in hill culture
Now that you have better understood what Hugelkultur is and what advantages and disadvantages it has, let's talk about the right way to build a Hugelkultur raised bed!
Design properly
Make sure you have a good frame for your bed.
If you use one of the birdies raised beds sold through the Epic Gardening store, you get a galvanized steel bed that will literally last for decades. This is the perfect setting to build your elevated garden.
You can also use a wooden frame, but remember, the goal of a hill culture system is to break down the wood in the bed. Your wooden walls can also be at risk. If you plan to use this method with a wooden frame, you'll need to replace your side panels as needed. Choose woods that decompose slowly, like cedar. It may cost more, but it will be worth it.
You can also use brick, concrete blocks, or stone to make walls for your beds. These methods may cost you, but like birdies beds, they will last for years. The downside to this is that they are much thicker, which can reduce the working size of your bed itself.
Start at the bottom
One of the coolest things about a spherical culture bed is that you can reuse some of the soil that is already in your yard. If you have a decent quality floor this is a great way to get the most out of your own topsoil while also raising the height to a more manageable level!
To do this method, dig out a few inches of the shallow soil in the area where your bed is located. Either leave some hard-packed dirt behind to support the sides of the bed or bury some bricks under the bed walls to support them and keep the bed from sinking. Lay this floor on a tarp and set it aside. You will use it later.
When you've prepared the shallow trench in your bed, pack those few inches with green trash. Ingredients from your garden, grass waste, fresh manure, compost (whether finished or unfinished), kitchen waste, and the like are excellent things to put in the first few inches of space. This creates a nitrogen layer in which you can embed your wood.
Work in your wood
Add logs to form the base of the hill culture raised bed.
Now it's time for your wood. But it can't be just any old wood. You have to plan a little for it.
You want your wood to stay below the half point in your raised bed, but you also need to have at least 8 inches of clean soil for the garden. So the height of your bed is important here.
A 30-inch bed can contain up to 15-inch wood since you still have 15-inch floor above that level. But a 15 "bed should have 6" of wood at most. You need to keep this 8 inch growing medium as the top layer for gardening purposes.
For flatter beds, I recommend using twigs and twigs as a source of wood. Bundle them tightly together, tied with a string like jute that also composts in beds. If you can, tuck grass clippings or other organic material into each bundle to fill in any gaps. Slide these into your green waste layer.
For higher beds, wood that is higher but still below the center of the bed can be used. Try to use dry or already rotting logs, as this will give you a green light for their decomposition.
Add an inch or two of green trash wrapped around the sides of the bed as you fill it with stuff. Ideally, you will enclose all of the wood in organic matter that will compost over time.
If you don't have any trunks, twigs, or twigs, you can use wood shavings. But if you do, I recommend arborist wood chips, which are high in green leaf material as well as trunk material. These wood chips compost faster because they come from a little bit of their own nitrogen source. However, beds in which these are used should also add additional organics as the wood chips break down faster than larger branches and require more nitrogen initially.
Once your layer of wood is in place, add more nitrogen-proof organic material. Again, you want at least 2 to 3 inches of this. Really wrap it up there and press down to fill in any existing columns. This will keep your soil from falling between the pieces of wood and also act as a protective nitrogen barrier for the lowest level of your soil.
But not the wood
There are tree species that are considered allelopathic. These trees have compounds in their wood or bark that act as natural herbicides and stop plants from germinating.
While laying the wood under your growing medium, you don't want to risk these compounds somehow getting into the area where the plant roots are. Hence, it is good to avoid certain types of wood, leaves, or wood chips when building your ball culture base, as this poses less risk to your plants.
Common allelopathic trees are walnut (especially black walnut), eucalyptus, tree of heaven, manzanita, sugar maple, red oak, sycamore maple, goldenrod, American elm, pepper tree, and black locust. Incorporating leaves or wood from these can potentially put your plants at risk. While they will eventually compost and lose the dangerous compounds, it is better to avoid them from the start.
Fill in with your growing medium
Apply your mixed soil to your beds.
After the hillside part of the bed is in place, the next step is to add back the soil that you removed from under the bed. Spread it evenly over the entire surface to include your filler material.
In addition, you need a soil medium that is high in organic matter and can hold a significant amount of water. I recommend either a mix like Mel & # 39; s Mix or something that has a lot of coconut and composted manure in it. You can add topsoil or other ingredients if you'd like.
Make sure you know the type of dirt when you mix in dirt. Sandy soils may require a little more moisture retention. Therefore work with additional coconut coconut, peat moss, worm cast or vermiculite. Clay soils should be broken up with a lot of leaf mold, plant compost, composted horse manure or cow dung and the like. Silty soils should be mixed very well with your other components to ensure they don't fall through directly and form a thick, sticky layer on your trunks or branches.
While you want this layer to retain moisture, you also want any excess water to drain away. It shouldn't puddle on the surface. Before filling, take a saucepan with your mixture and let it soak with water. If something sits on the surface for more than a few minutes, work in coarse sand or add some perlite to ensure better drainage.
Plant it and mulch it well
This hill culture raised bed is ready to be planted!
Now that your raised beds are full, it's time to move on to the final step: planting and mulching. You want to keep weeds from growing. The best way to do this is to completely cover your floor. Wherever a plant isn't, you'll want to cover it completely with mulch to reduce the chances of weeds filling it in.
In addition, hill culture beds can help hold back water as soon as the wood begins to compost. But, as with all raised beds, you want to reduce moisture evaporation in the top few inches of your growing medium. Since your wood is new, for the first one or two growing seasons you should make sure you have something that will slow down evaporation from the surface. I often apply a thick layer of compost between the plants and then add some wood shavings. This step significantly reduces both weeds and water waste. If you want to reduce water waste even further, use a waterer hose system to water under your layer of mulch.
Planting out your raised beds is a lot easier if you don't have to bend over that far. You will find that they are easier to weed and water. I love gardening in raised beds for this very reason, and so will you!
The green fingers behind this article:
Lorin Nielsen
Lifelong gardener
