How to Inexpensively and Effectively Fill a No-Dig Raised Bed for Almost No Cost: Use These 1/3 Filling Principles and They Will Also Feed Your Plants!

The Rusted Garden Seed and Garden Shop

How to Inexpensively and Effectively Fill a No-Dig Raised Bed for Almost No Cost: 

Use These 1/3 Filling Principles and They Will Also Feed Your Plants!

Filling large sided raised beds can cost 100's of dollars when using bagged potting mixes and other products. It works, but that is the most expensive way to do it. You can fill the bed for free or at a greatly reduced cost by following the principles of 1/3 filling. It is not new and it is known by many other names like hugelkultur, lasagna gardening and the simple... layering.  Of course, if  you have tons of fully broken down compost... you can just use compost to fill the beds, but most of have a limited supply.

How to Inexpensively Fill a Raised Garden Bed

This principles are best used for beds over 12 inches tall. A variation can be used for beds under 12 inches, which generally means using finer cut materials and materials that are a bit more composted or broken down. It is best to do this in the fall as to give your bed several months to establish. It can be done in the spring.  However, you may want to supplement the 'lower' layers with more nitrogen, such as blood meal, to prevent the decaying organic matter from competing with your spring plantings. Nitrogen is used by soil microbes to break down the organic matter. 

Filling a Raised Garden Bed at Little or No Cost

As you build the layers, you want to have 6-12 inches of good planting soil on top, depending on the height of the sides.. Save the good stuff for last. Most plants will establish well in that depth range of soil. If you have to spend money for materials, that is where you would spend it, the final top or planting layer. For plants like radishes, lettuces, spinach, arugula and other greens, 4 inches of good soil will work. The top layer is more important for the first year of using the bed. After a full season the bed will be established and continue to feed your plants year after year. All you have to do is add top dressings of compost, shredded hardwood, grass or combinations. Compost is always king but other materials will work as they will breakdown each season and get integrated into the raised bed by the soil life. You will not have to dig and turn this bed.

The principle is simple and can be adjusted based on the size of your bed and the materials available to you. The example 'fill', in the pictures and video, is based on a raised bed with 17 inch side. To start, the bottom is filled with coarser less decayed materials like tree branches and even logs. It can also include green grass and green yard waste as the 'green' has nitrogen and that will help the soil microbes breakdown the coarser less decayed materials. The materials in the bottom are initially less likely to impact the root systems of the plants but eventually they will enjoy what they find there, year after year, as it establishes. Cardboard can also be put down to cover over grass and weeds in shallower raised beds. It also is good to use in the lower layers as worms love it and it breaks down quickly.

Worms Love Cardboard

Coarser Materials in the Bottom & Grass Supplies Nitrogen

The bottom can also contain leaves, wood chips, materials you collected that are just starting to compost down (a couple months old). The bottom 1/3 is what will decay over time and feed your plants over the years, with help from the soil life. It will also hold moisture. An added bonus to this type of fill, is that you will have to water less and the layers will maintain even moisture over the seasons.

Materials for Filling the Lower 1/3 of the Raised Bed

Materials for Filling the Lower 1/3 of the Raised Bed

Materials for Filling the Lower 1/3 of the Raised Bed

Materials for Filling the Lower 1/3 of the Raised Bed

Partially Composted Material for Bottom or Middle 1/3

The next step is to move into better material to fill the middle 1/3. This is where I use a lot of earth from digging edges around my flower beds or when I am doing construction. Any earth will support the roots of the plants. You can also use composted materials that are not 100% composted down but getting close. A good volume addition at this point is peat moss or coco coir. They are less expensive than potting mix. They can also be used in the final or top 1/3 of filling the bed. Thinks of it this way... bottom 1/3 needs time, middle 1/3 is okay stuff and top 1/3 is better stuff for the plants to root and establish. They are so many variations to this. Don't follow this as an exact recipe but use it to create and experiment.

Takes Earth from Around Your Yard for Middle Filler

Fill the Middle Layer with Earth from the Yard

The middle layer can pretty much just be earth from around your yard. If you want, you can mix in peat moss, coco coir, compost as mentioned, but soil life will move through there over time and improve it. We will all have different resources available for the middle layer, and generally speaking, the whole filling process. The final layer should be your better layer of about 6 inches of 'good stuff'. You can buy potting mix or mix peat moss and any yard earth at a 50-50 ratio. You can mix in or completely use high quality compost to finish off the bed. They key is that the bottom 2/3 of the fill doesn't have to be costly. Just fill it and let Nature work her magic.

The general 1/3 filling principles will save you a lot of money and build great raised bed soil over time. If plants struggle the first year, don't be afraid to add higher nitrogen fertilizers, like blood meal, and/or water them often with water-soluble fertilizers, like fish emulsion.  Moving forward from year two, just add materials to the top of the raised bed and enjoy the harvest.

The Final 1/3 of the Filled Raised Garden Bed

Cheers,

Gary

Subscribe to my YouTube Channel The Rusted Garden Homestead

Nearly 500,000 Subscribers and Over 1250 Garden Videos Designed to Quickly Present Information!

Visit The Rusted Garden Seed and Garden Shop for your Seeds, Starting Supplies, Fabric Pots, Neem Oil, Peppermint and Other Oils, Calcium Nitrate and More. 
The Rusted Garden Seed and Garden Shop