Filling a Raised Bed on a Balcony – Hugelkultur Method

Raised beds on a balcony are still a new idea in 2021, which I am sure will be trending in a few years’ time. Garden enthusiasts don’t want to get limited by their space and raised bed on a balcony is the best answer to get a huge harvest from a small space.

We decided to build raised beds for our balcony this year. The detailed post on how we built the raised bed is available here.

One of the raised bed that we built for our balcony

Now that we have built the raised beds, the next step is going to be real fun, filling them up.

I have done a little bit of research on this and decided to fill my beds inspired by the Hugelkultur method. This a proven sustainable raised bed technique that the gardeners have been using for many years. In this method, different layers of materials are piled up together (just like a compost bin, but a little different).

They place heavy wood logs at the bottom, upon which waste from the garden like dried wood stems, twigs, old branches, leaves are piled up. This will layer will eventually decay very slowly, proving nutrients for the plants.

On top of this layer they lay compost (both full done and half done) and some kitchen scraps, pruned leaves from the garden.

And as the final top layer normal soil is filled on which the plants grow. The layers underneath will get composted eventually. This is the idea behind the Hugelkultur method. It is basically building a living garden bed.

But how do we bring this concept to a balcony space? The limiting factors are ofcourse the space, weight the balcony can take.

We have built a 100L x 40B x 40H cm raised bed. Since the depth of our raised bed is less than half of a classic raised bed, placing logs is out of question. So what I decided to do is to implement a miniature hugelkultur bed on my balcony.

The Layers:

Layer 1: Dead wood materials (40%)

For this layer, I chose the following materials:

  • Pine bark (wood chips are also an alternative)
  • dead grass clippings
  • twigs
  • dried plant stems
  • root balls of plants from last year
  • some old/spent potting soil

This layer acts as drainage for the whole bed which will avoid water clogging the bed and prevent root rot. Eventually, the deadwood and grass will decay providing nutrients for the plant. The pine bark will get mushy and act like a sponge that can store moisture. Plant roots can take up water from them which means less watering for us.

Layer 1: Pine bark
Layer 1: Pine bark
Layer 1: twigs, dried grass clippings, old soil
Layer 1: twigs, dried grass clippings, old soil

Layer 2: Compost (30%)

I used the following materials as the compost layer.

  • store-bought compost
  • homemade compost (not 100% composted)
  • kitchen scraps (pruned leaves from the garden can also be used)

Consider this as the green layer in a compost pile. At the time of filling, I only had access to one bucket of homemade compost. Therefore, I had to buy store-bought compost. First I used a small layer of store-bought compost, then filled in the half-done homemade compost and kitchen scraps, and finally topped with store-bought compost.

Compost will be the nutrient-rich layer for the plant. Since we have partially done compost and kitchen scraps in this layer, the composting process will go on. This will increase the heat inside the raised bed, keeping the roots of the plants warm even if the temperature outside is cold.

Layer 2: Homemade compost
Layer 2: Homemade compost
Layer 2: Store-bought compost
Layer 2: Store-bought compost

Layer 3: Vegetable garden soil (30 %)

The final layer on top is the vegetable garden soil also bought from the store. This will also contain some nutrients to kick start the growth of the plants. 

Layer 3: Vegetable garden soil
Layer 3: Vegetable garden soil
3 layers of a balcony raised bed
3 layers of a balcony raised bed

Pros of Hugelkultur method

There are several advantages to using this technique to fill up a raised bed. Some of them which convinced me to chose this method are:

  • This provides enough nutrients for the plants for the entire season. I will give them some worm casting tea once in a month depending on the growth of the plant. But other than that, the plants will be fed by the compost layer.
  • Since the bottom layers are composed of bark and compost, they can retain more moisture which will reduce our effort of watering them frequently.
  • Composting is an ongoing process in a hugelkultur raised bed. This means there will be enough heat to keep the plant roots warm. This can extend the growing season. How cool is that?
  • The whole method is less expensive as we try to use the waste materials around the house to fill up the raised bed. Otherwise to fill my bed, I would have to buy around 160 l of soil just for one raised bed. Think about the weight it would add to the balcony.

In Germany, the three layers for a raised bed are available in the market to buy, in case if you don’t have access to dead leaves/twigs or homemade compost. This technique is proven to provide a successful and productive bed which will result in a huge harvest. Let us see how mine turns out.

I already feel like there is a farm on my balcony :D. I will be planting them as soon as the weather gets better here. Updates on my experience using a raised bed will be added here or as another post.

Farm on a balcony
Farm on a balcony 🙂

Here you can find a video on how to fill raised beds and more.

Happy gardening! 🙂