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How to fill a raised garden bed (and save money)

Raised garden beds are so very convenient and can be a great way to grow food on practically any land. But raised beds can be expensive to fill with soil, especially if they’re really tall. The good news is that you can use a variety of materials to cheaply fill raised beds and save money on soil.

growing vegetables in raised metal garden bed

Types of Raised Beds

Raised garden beds are basically mounds of soil that plants are grown in, instead of using the native soil like is done with row growing. There are many ways of making raised beds.

Wooden boxes – Building wooden boxes is a popular way of creating raised beds. Most of our raised beds are made with wood. One of the benefits of using wood is that they can be fairly easy to put together. You can by three 8-foot long boards and just cut one in half to build a 4’x8′ bed. Another benefit is that you can make them as tall as you want by adding more wood. The downside of wooden boxes is that they will deteriorate over time.

Cinder blocks – We have several garden beds made out of cinder blocks. The upside of using cinderblocks is that they won’t deteriorate, so it’s a one time purchase. They are also fairly easy to set up and don’t require any tools or building skills. A downside is that it can be time consuming to get them level and that you can’t easily make them taller.

Metal beds – Metal beds are becoming popular and for some good reasons. They won’t deteriorate and will last many years and they’re super easy to put together. It can certainly be a one person job. We have an Olle Gardens 32″ rectangle that we use for low growing crops such as herbs and greens. In time we’ll probably add more of these to our garden so we can continue gardening as we age.

Hugelkultur – Hugelkultur beds are built by layering logs and other compostable material such as rotted hay, leaves, animal bedding, compost and soil. These can be quite large, up to 5 feet, but they don’t have to be. While the term “hugelkultur” is German, this type of gardening is practiced in many cultures. We have a friend from Kenya who told me that when they build a house in her village, they dig the clay soil for making the bricks from the area that will be the garden. When the house is complete they have a deep sunken area where the garden is going to be. They fill the area with logs, branches, leaves, animal bedding and other compostable items. The next year they’ll start planting in the garden.

Filling a Raised Garden Bed

I really like the hugelkultur method and use that to cheaply fill our raised garden beds. I’ve always used our chicken bedding, leaves and pine needles when I’m filling our raised beds to save on purchasing soil. The Olle Garden is so tall that I decided to also add some rotted logs and branches that we had laying around.

The idea is to stack the item with the thing that takes the longest to break down on the bottom. The layers for a high raised garden might look be (from bottom to top) rotted logs, branches, leaf mold, animal bedding, rotting hay, lawn clippings, soil, and compost.

Below are some things that you can use to fill raised garden beds. You don’t need to use all of them, just use what you can easily get. That being said, I do think it’s important to use a variety of items.

  • Cardboard and/or newspaper – Cardboard can be put at the bottom of the bed. With a 32″ inch bed, it’s probably not necessary to lay cardboard to help with weed control but if the bed is less than 18″ I would definitely lay cardboard in the bottom of the bed.
  • Logs – Logs can really help fill up the garden bed. It’s best to use logs that are already rotting as they will use less nitrogen as they breakdown than newer logs will. If you’re using newer logs, you’ll want to be sure to add a nitrogen layer to the pile.
  • Branches – Branches will break down faster than logs and can be a little unruly. I like to cut them so that they lay pretty evenly in the bed. Branches will require nitrogen when they’re breaking down so it’s perfectly fine to add branches that still have green leaves on them.
  • Leaf mold – Decaying leaves are called “leaf mold” and are really great for the garden. The leaves are full of micro-organisms and worms that will help break down the larger items and turn them into soil. We collect our neighbors’ leaves in the winter and let them sit and begin to decompose before we put them in the garden.
  • Animal bedding – The bedding of livestock animals can be used in the garden but most of it needs to be aged first. When we clean out the chicken coop we pile the bedding and let it age for at least six months before we use it. Other manures need to be handled differently so be sure to follow these guidelines when using animal bedding.
  • Rotting hay – Old hay will add structure to garden soil and is a great item to use in a raised bed. If we have rotting hay we’ll use it in a lower layer and use hay that’s not rotting as mulch.
  • Pine needles – We have several large pine trees on our property and use the pine needles to help build soil in our raised beds. Contrary to popular belief adding pine needles to the garden will not make the soil more acidic.
  • Lawn clippings – Green lawn clippings will add a nitrogen rich layer to the garden bed. When organic matter decomposes it can use quite a bit of nitrogen. This layer will help keep the decomposing layer from pulling nitrogen from the soil above.
  • Coffee grounds – Coffee grounds are another great item to use to add nitrogen to the mix. You can get large amounts of coffee grounds from local coffee shops for free.
  • Soil – For a raised bed you’ll want at least 6 inches of garden soil for the plants to grow in. Depending on what you’re growing, you might need 12 or more inches. Choose a quality soil made for raised beds which means it will be light and loamy. This will allow for proper drainage. Heavy soil like top soil will get compacted. You can also make your own soil with peat or coco coir, compost and vermiculite.
  • Compost – Depending on the soil you use you might want to add a top dressing of compost. You can buy bagged compost that’s made from animal manure, mushrooms (which is the leftover soil from growing mushrooms) and other items. If you compost at home, use that first if you have some ready.
  • Mulch – I like to mulch all our beds since we live in a really warm climate. Mulch is great for weed control and water retention. There are many things you can use for mulch such as leaves, hay, straw, and wood chips – just use what you have.
olle garden metal raised bed kit

Review of Olle Gardens Metal Raised Beds

As I mentioned earlier we have an Olle Gardens 32″ rectangle metal garden bed. We got it because my husband has cancer and as it progresses it’s getting harder for him to bend over. That makes harvesting and enjoying the garden harder for him. With a tall garden bed he can access the the items we grow without having to bend over.

The Olle Garden came with everything I need to put it together – the panels, bolts, nuts, washers, wrench and clear, step-by-step instructions. I was able to put it together without any help. Since it’s so tall, it was a little tricky and I had to lay the bed on it’s side to get the bottom bolts in. If we had gotten a shorter bed, that would not be a problem at all.

Since this bed is so tall, we’re growing low growing plants in it – such as herbs and greens. I don’t want to grow tall plants such as okra or tomatoes in it (unless I were growing a short tomato variety.)

The 17″ beds would be good for growing taller vegetables such as okra, tomatoes, and even corn.

We love our Olle Garden metal garden bed and think you will too. In fact, we have a 10% discount code for you. You can use this link and get 10% off (the code will auto populate.)

Thanks for sharing with your friends!